Remove to_cstring() naming convention ambiguity

Add a trait for str.strdup() to replace to_cstring() which avoid the
signature ambiguity with .to_string().

Also instruduce CString::yolo() as a shortcut to
CString::new().unwrap() and use it whenever the variable does can be
deallocated by going out of scope.  This is less error prone.

Use some Path.to_c_string() functions where possible.

deltachat-ffi/src/lib.rs

@@ -15,6 +15,7 @@ use num_traits::{FromPrimitive, ToPrimitive};
 use std::ptr;
 use std::str::FromStr;
 
+use deltachat::dc_tools::StrExt;
 use deltachat::*;
 
 // TODO: constants
@@ -126,10 +127,7 @@ pub unsafe extern "C" fn dc_get_config(
     let context = &*context;
 
     match config::Config::from_str(dc_tools::as_str(key)) {
-        Ok(key) => {
+        Ok(key) => context.get_config(key).unwrap_or_default().strdup(),
-            let value = context.get_config(key).unwrap_or_default();
-            dc_tools::to_cstring(value)
-        }
         Err(_) => std::ptr::null_mut(),
     }
 }
@@ -154,7 +152,7 @@ pub unsafe extern "C" fn dc_get_oauth2_url(
     let addr = dc_tools::to_string(addr);
     let redirect = dc_tools::to_string(redirect);
     match oauth2::dc_get_oauth2_url(context, addr, redirect) {
-        Some(res) => dc_tools::to_cstring(res),
+        Some(res) => res.strdup(),
         None => std::ptr::null_mut(),
     }
 }

examples/repl/cmdline.rs

@@ -147,7 +147,7 @@ unsafe fn poke_spec(context: &Context, spec: *const libc::c_char) -> libc::c_int
         } else {
             current_block = 7149356873433890176;
         }
-        real_spec = to_cstring(rs.unwrap_or_default());
+        real_spec = rs.unwrap_or_default().strdup();
     }
     match current_block {
         8522321847195001863 => {}
@@ -184,11 +184,10 @@ unsafe fn poke_spec(context: &Context, spec: *const libc::c_char) -> libc::c_int
                         if name.ends_with(".eml") {
                             let path_plus_name = format!("{}/{}", as_str(real_spec), name);
                             info!(context, 0, "Import: {}", path_plus_name);
-                            let path_plus_name_c = to_cstring(path_plus_name);
+                            let path_plus_name_c = CString::yolo(path_plus_name);
-                            if 0 != dc_poke_eml_file(context, path_plus_name_c) {
+                            if 0 != dc_poke_eml_file(context, path_plus_name_c.as_ptr()) {
                                 read_cnt += 1
                             }
-                            free(path_plus_name_c as *mut _);
                         }
                     }
                     current_block = 1622411330066726685;
@@ -386,13 +385,13 @@ pub unsafe fn dc_cmdline(context: &Context, line: &str) -> Result<(), failure::E
     let arg1_c = if arg1.is_empty() {
         std::ptr::null()
     } else {
-        to_cstring(arg1) as *const _
+        arg1.strdup() as *const _
     };
     let arg2 = args.next().unwrap_or_default();
     let arg2_c = if arg2.is_empty() {
         std::ptr::null()
     } else {
-        to_cstring(arg2) as *const _
+        arg2.strdup() as *const _
     };
 
     match arg0 {
@@ -928,13 +927,11 @@ pub unsafe fn dc_cmdline(context: &Context, line: &str) -> Result<(), failure::E
             ensure!(!sel_chat.is_null(), "No chat selected.");
             ensure!(!arg1.is_empty(), "No message text given.");
 
-            let msg = to_cstring(format!("{} {}", arg1, arg2));
+            let msg = CString::yolo(format!("{} {}", arg1, arg2));
 
-            if 0 != dc_send_text_msg(context, dc_chat_get_id(sel_chat), msg) {
+            if 0 != dc_send_text_msg(context, dc_chat_get_id(sel_chat), msg.as_ptr()) {
                 println!("Message sent.");
-                free(msg as *mut _);
             } else {
-                free(msg as *mut _);
                 bail!("Sending failed.");
             }
         }

examples/repl/main.rs

@@ -481,7 +481,7 @@ unsafe fn handle_cmd(line: &str, ctx: Arc<RwLock<Context>>) -> Result<ExitResult
     let arg1_c = if arg1.is_empty() {
         std::ptr::null()
     } else {
-        to_cstring(arg1)
+        arg1.strdup()
     };
 
     match arg0 {

src/chatlist.rs

@@ -256,7 +256,7 @@ impl<'a> Chatlist<'a> {
 
         let mut ret = dc_lot_new();
         if index >= self.ids.len() {
-            (*ret).text2 = to_cstring("ErrBadChatlistIndex");
+            (*ret).text2 = "ErrBadChatlistIndex".strdup();
             return ret;
         }
 
@@ -267,7 +267,7 @@ impl<'a> Chatlist<'a> {
             chat = dc_chat_new(self.context);
             let chat_to_delete = chat;
             if !dc_chat_load_from_db(chat, self.ids[index].0) {
-                (*ret).text2 = to_cstring("ErrCannotReadChat");
+                (*ret).text2 = "ErrCannotReadChat".strdup();
                 dc_chat_unref(chat_to_delete);
 
                 return ret;
@@ -293,7 +293,7 @@ impl<'a> Chatlist<'a> {
         if (*chat).id == DC_CHAT_ID_ARCHIVED_LINK as u32 {
             (*ret).text2 = dc_strdup(0 as *const libc::c_char)
         } else if lastmsg.is_null() || (*lastmsg).from_id == DC_CONTACT_ID_SELF as u32 {
-            (*ret).text2 = to_cstring(self.context.stock_str(StockMessage::NoMessages));
+            (*ret).text2 = self.context.stock_str(StockMessage::NoMessages).strdup();
         } else {
             dc_lot_fill(ret, lastmsg, chat, lastcontact, self.context);
         }

src/config.rs

@@ -1,3 +1,5 @@
+use std::ffi::CString;
+
 use strum::{EnumProperty, IntoEnumIterator};
 use strum_macros::{AsRefStr, Display, EnumIter, EnumProperty, EnumString};
 
@@ -72,10 +74,8 @@ impl Context {
                 let rel_path = self.sql.get_config(self, key);
                 rel_path.map(|p| {
                     let v = unsafe {
-                        let n = to_cstring(p);
+                        let n = CString::yolo(p);
-                        let res = dc_get_abs_path(self, n);
+                        dc_get_abs_path(self, n.as_ptr())
-                        free(n as *mut libc::c_void);
-                        res
                     };
                     let r = to_string(v);
                     unsafe { free(v as *mut _) };

src/context.rs

@@ -483,7 +483,7 @@ pub unsafe fn dc_get_info(context: &Context) -> *mut libc::c_char {
         fingerprint_str,
     );
 
-    to_cstring(res)
+    res.strdup()
 }
 
 pub unsafe fn dc_get_version_str() -> *mut libc::c_char {

src/dc_array.rs

@@ -271,7 +271,7 @@ pub unsafe fn dc_array_get_marker(array: *const dc_array_t, index: size_t) -> *m
 
     if let dc_array_t::Locations(v) = &*array {
         if let Some(s) = &v[index].marker {
-            to_cstring(s)
+            s.strdup()
         } else {
             std::ptr::null_mut()
         }
@@ -375,7 +375,7 @@ pub unsafe fn dc_array_get_string(
                     res + sep + &n.to_string()
                 }
             });
-        to_cstring(res)
+        res.strdup()
     } else {
         panic!("Attempt to get string from array of other type");
     }

src/dc_chat.rs

@@ -137,14 +137,8 @@ pub fn dc_chat_load_from_db(chat: *mut Chat, chat_id: u32) -> bool {
 
             c.id = row.get(0)?;
             c.type_0 = row.get(1)?;
-            c.name = {
+            c.name = unsafe { row.get::<_, String>(2)?.strdup() };
-                let raw: String = row.get(2)?;
+            c.grpid = unsafe { row.get::<_, String>(3)?.strdup() };
-                unsafe { to_cstring(raw) }
-            };
-            c.grpid = {
-                let raw: String = row.get(3)?;
-                unsafe { to_cstring(raw) }
-            };
 
             c.param = row.get::<_, String>(4)?.parse().unwrap_or_default();
             c.archived = row.get(5)?;
@@ -172,24 +166,27 @@ pub fn dc_chat_load_from_db(chat: *mut Chat, chat_id: u32) -> bool {
             match c.id {
                 1 => unsafe {
                     free((*chat).name as *mut libc::c_void);
-                    (*chat).name = to_cstring((*chat).context.stock_str(StockMessage::DeadDrop));
+                    (*chat).name = (*chat).context.stock_str(StockMessage::DeadDrop).strdup();
                 },
                 6 => unsafe {
                     free((*chat).name as *mut libc::c_void);
                     let tempname = (*chat).context.stock_str(StockMessage::ArchivedChats);
                     let cnt = dc_get_archived_cnt((*chat).context);
-                    (*chat).name = to_cstring(format!("{} ({})", tempname, cnt));
+                    (*chat).name = format!("{} ({})", tempname, cnt).strdup();
                 },
                 5 => unsafe {
                     free((*chat).name as *mut libc::c_void);
-                    (*chat).name = to_cstring((*chat).context.stock_str(StockMessage::StarredMsgs));
+                    (*chat).name = (*chat)
+                        .context
+                        .stock_str(StockMessage::StarredMsgs)
+                        .strdup();
                 },
                 _ => {
                     if unsafe { &(*chat).param }.exists(Param::Selftalk) {
                         unsafe {
                             free((*chat).name as *mut libc::c_void);
                             (*chat).name =
-                                to_cstring((*chat).context.stock_str(StockMessage::SelfMsg));
+                                (*chat).context.stock_str(StockMessage::SelfMsg).strdup();
                         }
                     }
                 }
@@ -398,7 +395,7 @@ unsafe fn prepare_msg_common<'a>(
         let mut pathNfilename = (*msg)
             .param
             .get(Param::File)
-            .map(|s| to_cstring(s))
+            .map(|s| s.strdup())
             .unwrap_or_else(|| std::ptr::null_mut());
         if pathNfilename.is_null() {
             error!(
@@ -516,16 +513,15 @@ unsafe fn prepare_msg_raw(
         if from.is_none() {
             error!(context, 0, "Cannot send message, not configured.",);
         } else {
-            let from_c = to_cstring(from.unwrap());
+            let from_c = CString::yolo(from.unwrap());
             new_rfc724_mid = dc_create_outgoing_rfc724_mid(
                 if (*chat).type_0 == 120 || (*chat).type_0 == 130 {
                     (*chat).grpid
                 } else {
                     0 as *mut libc::c_char
                 },
-                from_c,
+                from_c.as_ptr(),
             );
-            free(from_c as *mut _);
 
             if (*chat).type_0 == DC_CHAT_TYPE_SINGLE {
                 if let Some(id) = context.sql.query_row_col(
@@ -789,9 +785,9 @@ unsafe fn get_parent_mime_headers(
                  FROM msgs WHERE chat_id=? AND from_id!=?);",
                 params![(*chat).id as i32, 1],
                 |row| {
-                    *parent_rfc724_mid = to_cstring(row.get::<_, String>(0)?);
+                    *parent_rfc724_mid = row.get::<_, String>(0)?.strdup();
-                    *parent_in_reply_to = to_cstring(row.get::<_, String>(1)?);
+                    *parent_in_reply_to = row.get::<_, String>(1)?.strdup();
-                    *parent_references = to_cstring(row.get::<_, String>(2)?);
+                    *parent_references = row.get::<_, String>(2)?.strdup();
                     Ok(())
                 },
             )
@@ -807,9 +803,9 @@ unsafe fn get_parent_mime_headers(
                      FROM msgs WHERE chat_id=? AND from_id==?);",
                     params![(*chat).id as i32, 1],
                     |row| {
-                        *parent_rfc724_mid = to_cstring(row.get::<_, String>(0)?);
+                        *parent_rfc724_mid = row.get::<_, String>(0)?.strdup();
-                        *parent_in_reply_to = to_cstring(row.get::<_, String>(1)?);
+                        *parent_in_reply_to = row.get::<_, String>(1)?.strdup();
-                        *parent_references = to_cstring(row.get::<_, String>(2)?);
+                        *parent_references = row.get::<_, String>(2)?.strdup();
                         Ok(())
                     },
                 )
@@ -1012,7 +1008,7 @@ unsafe fn set_draft_raw(context: &Context, chat_id: uint32_t, msg: *mut dc_msg_t
             let mut pathNfilename = (*msg)
                 .param
                 .get(Param::File)
-                .map(|s| to_cstring(s))
+                .map(|s| s.strdup())
                 .unwrap_or_else(|| std::ptr::null_mut());
             if pathNfilename.is_null() {
                 OK_TO_CONTINUE = false;
@@ -1620,12 +1616,14 @@ pub unsafe fn dc_add_contact_to_chat_ex(
                     if OK_TO_CONTINUE {
                         if (*chat).param.get_int(Param::Unpromoted).unwrap_or_default() == 0 {
                             (*msg).type_0 = Viewtype::Text;
-                            (*msg).text = to_cstring(context.stock_system_msg(
+                            (*msg).text = context
+                                .stock_system_msg(
                                     StockMessage::MsgAddMember,
                                     as_str((*contact).addr),
                                     "",
                                     DC_CONTACT_ID_SELF as uint32_t,
-                            ));
+                                )
+                                .strdup();
                             (*msg).param.set_int(Param::Cmd, 4);
                             if !(*contact).addr.is_null() {
                                 (*msg).param.set(Param::Arg, as_str((*contact).addr));
@@ -1733,19 +1731,23 @@ pub unsafe fn dc_remove_contact_from_chat(
                         (*msg).type_0 = Viewtype::Text;
                         if (*contact).id == 1 as libc::c_uint {
                             dc_set_group_explicitly_left(context, (*chat).grpid);
-                            (*msg).text = to_cstring(context.stock_system_msg(
+                            (*msg).text = context
+                                .stock_system_msg(
                                     StockMessage::MsgGroupLeft,
                                     "",
                                     "",
                                     DC_CONTACT_ID_SELF as u32,
-                            ));
+                                )
+                                .strdup();
                         } else {
-                            (*msg).text = to_cstring(context.stock_system_msg(
+                            (*msg).text = context
+                                .stock_system_msg(
                                     StockMessage::MsgDelMember,
                                     as_str((*contact).addr),
                                     "",
                                     DC_CONTACT_ID_SELF as u32,
-                            ));
+                                )
+                                .strdup();
                         }
                         (*msg).param.set_int(Param::Cmd, 5);
                         if !(*contact).addr.is_null() {
@@ -1846,12 +1848,14 @@ pub unsafe fn dc_set_chat_name(
                 {
                     if (*chat).param.get_int(Param::Unpromoted).unwrap_or_default() == 0 {
                         (*msg).type_0 = Viewtype::Text;
-                        (*msg).text = to_cstring(context.stock_system_msg(
+                        (*msg).text = context
+                            .stock_system_msg(
                                 StockMessage::MsgGrpName,
                                 as_str((*chat).name),
                                 as_str(new_name),
                                 DC_CONTACT_ID_SELF as u32,
-                        ));
+                            )
+                            .strdup();
                         (*msg).param.set_int(Param::Cmd, 2);
                         if !(*chat).name.is_null() {
                             (*msg).param.set(Param::Arg, as_str((*chat).name));
@@ -1918,7 +1922,8 @@ pub unsafe fn dc_set_chat_profile_image(
                             (*msg).param.set_int(Param::Cmd, 3);
                             (*msg).param.set(Param::Arg, as_str(new_image_rel));
                             (*msg).type_0 = Viewtype::Text;
-                            (*msg).text = to_cstring(context.stock_system_msg(
+                            (*msg).text = context
+                                .stock_system_msg(
                                     if !new_image_rel.is_null() {
                                         StockMessage::MsgGrpImgChanged
                                     } else {
@@ -1927,7 +1932,8 @@ pub unsafe fn dc_set_chat_profile_image(
                                     "",
                                     "",
                                     DC_CONTACT_ID_SELF as uint32_t,
-                            ));
+                                )
+                                .strdup();
                             (*msg).id = dc_send_msg(context, chat_id, msg);
                             context.call_cb(
                                 Event::MSGS_CHANGED,
@@ -2094,7 +2100,10 @@ pub unsafe fn dc_chat_get_subtitle(chat: *const Chat) -> *mut libc::c_char {
 
     let mut ret: *mut libc::c_char = std::ptr::null_mut();
     if (*chat).type_0 == 100 && (*chat).param.exists(Param::Selftalk) {
-        ret = to_cstring((*chat).context.stock_str(StockMessage::SelfTalkSubTitle));
+        ret = (*chat)
+            .context
+            .stock_str(StockMessage::SelfTalkSubTitle)
+            .strdup();
     } else if (*chat).type_0 == 100 {
         let ret_raw: String = (*chat)
             .context
@@ -2108,17 +2117,16 @@ pub unsafe fn dc_chat_get_subtitle(chat: *const Chat) -> *mut libc::c_char {
                 0,
             )
             .unwrap_or_else(|| "Err".into());
-        ret = to_cstring(ret_raw);
+        ret = ret_raw.strdup();
     } else if (*chat).type_0 == 120 || (*chat).type_0 == 130 {
         if (*chat).id == 1 {
-            ret = to_cstring((*chat).context.stock_str(StockMessage::DeadDrop));
+            ret = (*chat).context.stock_str(StockMessage::DeadDrop).strdup();
         } else {
             let cnt = dc_get_chat_contact_cnt((*chat).context, (*chat).id);
-            ret = to_cstring(
+            ret = (*chat)
-                (*chat)
                 .context
-                    .stock_string_repl_int(StockMessage::Member, cnt),
+                .stock_string_repl_int(StockMessage::Member, cnt)
-            );
+                .strdup();
         }
     }
     return if !ret.is_null() {
@@ -2146,7 +2154,11 @@ pub unsafe fn dc_chat_get_profile_image(chat: *const Chat) -> *mut libc::c_char
     let mut contacts: *mut dc_array_t = 0 as *mut dc_array_t;
     let mut contact: *mut dc_contact_t = 0 as *mut dc_contact_t;
     if !(chat.is_null() || (*chat).magic != 0xc4a7c4a7u32) {
-        image_rel = to_cstring((*chat).param.get(Param::ProfileImage).unwrap_or_default());
+        image_rel = (*chat)
+            .param
+            .get(Param::ProfileImage)
+            .unwrap_or_default()
+            .strdup();
         if !image_rel.is_null() && 0 != *image_rel.offset(0isize) as libc::c_int {
             image_abs = dc_get_abs_path((*chat).context, image_rel)
         } else if (*chat).type_0 == 100i32 {

src/dc_configure.rs

@@ -1102,14 +1102,14 @@ unsafe fn moz_autoconfigure(
         tag_config: 0,
     };
 
-    let url_c = to_cstring(url);
+    let url_c = url.strdup();
     let xml_raw = read_autoconf_file(context, url_c);
     free(url_c as *mut libc::c_void);
     if xml_raw.is_null() {
         return None;
     }
 
-    moz_ac.in_emaillocalpart = to_cstring(&param_in.addr);
+    moz_ac.in_emaillocalpart = param_in.addr.strdup();
     let p = strchr(moz_ac.in_emaillocalpart, '@' as i32);
 
     if p.is_null() {
@@ -1166,7 +1166,7 @@ unsafe fn moz_autoconfigure_text_cb(
     let mut moz_ac: *mut moz_autoconfigure_t = userdata as *mut moz_autoconfigure_t;
     let mut val: *mut libc::c_char = dc_strdup(text);
     dc_trim(val);
-    let addr = to_cstring(&(*moz_ac).in_0.addr);
+    let addr = (*moz_ac).in_0.addr.strdup();
     dc_str_replace(
         &mut val,
         b"%EMAILADDRESS%\x00" as *const u8 as *const libc::c_char,
@@ -1306,7 +1306,7 @@ fn read_autoconf_file(context: &Context, url: *const libc::c_char) -> *mut libc:
         .send()
         .and_then(|mut res| res.text())
     {
-        Ok(res) => unsafe { to_cstring(res) },
+        Ok(res) => unsafe { res.strdup() },
         Err(_err) => {
             info!(context, 0, "Can\'t read file.",);
 
@@ -1322,7 +1322,7 @@ unsafe fn outlk_autodiscover(
 ) -> Option<dc_loginparam_t> {
     let current_block: u64;
     let mut xml_raw: *mut libc::c_char = 0 as *mut libc::c_char;
-    let mut url = to_cstring(url__);
+    let mut url = url__.strdup();
     let mut outlk_ad = outlk_autodiscover_t {
         in_0: param_in,
         out: dc_loginparam_new(),

src/dc_contact.rs

@@ -278,14 +278,13 @@ pub unsafe fn dc_contact_load_from_db(
 
     if contact_id == 1 as libc::c_uint {
         (*contact).id = contact_id;
-        (*contact).name = to_cstring((*contact).context.stock_str(StockMessage::SelfMsg));
+        (*contact).name = (*contact).context.stock_str(StockMessage::SelfMsg).strdup();
-        (*contact).addr = to_cstring(
+        (*contact).addr = (*contact)
-            (*contact)
             .context
             .sql
             .get_config((*contact).context, "configured_addr")
-                .unwrap_or_default(),
+            .unwrap_or_default()
-        );
+            .strdup();
         true
     } else {
         sql.query_row(
@@ -293,11 +292,11 @@ pub unsafe fn dc_contact_load_from_db(
             params![contact_id as i32],
             |row| {
                 (*contact).id = contact_id;
-                (*contact).name = to_cstring(row.get::<_, String>(0)?);
+                (*contact).name = row.get::<_, String>(0)?.strdup();
-                (*contact).addr = to_cstring(row.get::<_, String>(1)?);
+                (*contact).addr = row.get::<_, String>(1)?.strdup();
                 (*contact).origin = row.get(2)?;
                 (*contact).blocked = row.get::<_, Option<i32>>(3)?.unwrap_or_default();
-                (*contact).authname = to_cstring(row.get::<_, String>(4)?);
+                (*contact).authname = row.get::<_, String>(4)?.strdup();
                 Ok(())
             }
         ).is_ok()
@@ -726,7 +725,7 @@ pub unsafe fn dc_get_contact_encrinfo(
     free(fingerprint_other_verified as *mut libc::c_void);
     free(fingerprint_other_unverified as *mut libc::c_void);
 
-    to_cstring(ret)
+    ret.strdup()
 }
 
 unsafe fn cat_fingerprint(
@@ -901,7 +900,7 @@ pub fn dc_contact_get_profile_image(contact: *const dc_contact_t) -> *mut libc::
     if unsafe { (*contact).id } == 1 {
         let context = unsafe { (*contact) }.context;
         if let Some(avatar) = context.get_config(config::Config::Selfavatar) {
-            image_abs = unsafe { to_cstring(avatar) };
+            image_abs = unsafe { avatar.strdup() };
         }
     }
     // TODO: else get image_abs from contact param

src/dc_dehtml.rs

@@ -53,7 +53,7 @@ pub unsafe fn dc_dehtml(buf_terminated: *mut libc::c_char) -> *mut libc::c_char
     dc_saxparser_parse(&mut saxparser, buf_terminated);
     free(dehtml.last_href as *mut libc::c_void);
 
-    to_cstring(dehtml.strbuilder)
+    dehtml.strbuilder.strdup()
 }
 
 unsafe fn dehtml_text_cb(

src/dc_e2ee.rs

@@ -177,16 +177,12 @@ pub unsafe fn dc_e2ee_encrypt(
                                     let p = peerstates[i as usize]
                                         .render_gossip_header(min_verified as usize);
 
-                                    if p.is_some() {
+                                    if let Some(header) = p {
-                                        let header = to_cstring(p.unwrap());
                                         mailimf_fields_add(
                                             imffields_encrypted,
                                             mailimf_field_new_custom(
-                                                strdup(
+                                                "Autocrypt-Gossip".strdup(),
-                                                    b"Autocrypt-Gossip\x00" as *const u8
+                                                header.strdup(),
-                                                        as *const libc::c_char,
-                                                ),
-                                                header,
                                             ),
                                         );
                                     }
@@ -296,7 +292,7 @@ pub unsafe fn dc_e2ee_encrypt(
                                 sign_key.as_ref(),
                             ) {
                                 let ctext_bytes = ctext_v.len();
-                                let ctext = to_cstring(ctext_v);
+                                let ctext = ctext_v.strdup();
                                 (*helper).cdata_to_free = ctext as *mut _;
 
                                 /* create MIME-structure that will contain the encrypted text */
@@ -354,13 +350,11 @@ pub unsafe fn dc_e2ee_encrypt(
                         14181132614457621749 => {}
                         _ => {
                             let aheader = Aheader::new(addr, public_key, prefer_encrypt);
-                            let rendered = to_cstring(aheader.to_string());
-
                             mailimf_fields_add(
                                 imffields_unprotected,
                                 mailimf_field_new_custom(
-                                    strdup(b"Autocrypt\x00" as *const u8 as *const libc::c_char),
+                                    "Autocrypt".strdup(),
-                                    rendered,
+                                    aheader.to_string().strdup(),
                                 ),
                             );
                         }

src/dc_imex.rs

@@ -515,7 +515,7 @@ pub unsafe fn dc_normalize_setup_code(
         p1 = p1.offset(1);
     }
 
-    to_cstring(out)
+    out.strdup()
 }
 
 #[allow(non_snake_case)]
@@ -524,16 +524,14 @@ pub unsafe fn dc_job_do_DC_JOB_IMEX_IMAP(context: &Context, job: *mut dc_job_t)
     let mut success: libc::c_int = 0;
     let mut ongoing_allocated_here: libc::c_int = 0;
     let what: libc::c_int;
-    let mut param1 = 0 as *mut libc::c_char;
-    let mut param2 = 0 as *mut libc::c_char;
 
     if !(0 == dc_alloc_ongoing(context)) {
         ongoing_allocated_here = 1;
         what = (*job).param.get_int(Param::Cmd).unwrap_or_default();
-        param1 = to_cstring((*job).param.get(Param::Arg).unwrap_or_default());
+        let param1 = CString::yolo((*job).param.get(Param::Arg).unwrap_or_default());
-        param2 = to_cstring((*job).param.get(Param::Arg2).unwrap_or_default());
+        let _param2 = CString::yolo((*job).param.get(Param::Arg2).unwrap_or_default());
 
-        if strlen(param1) == 0 {
+        if strlen(param1.as_ptr()) == 0 {
             error!(context, 0, "No Import/export dir/file given.",);
         } else {
             info!(context, 0, "Import/export process started.",);
@@ -551,7 +549,7 @@ pub unsafe fn dc_job_do_DC_JOB_IMEX_IMAP(context: &Context, job: *mut dc_job_t)
                         );
                         current_block = 3568988166330621280;
                     } else {
-                        dc_create_folder(context, param1);
+                        dc_create_folder(context, param1.as_ptr());
                         current_block = 4495394744059808450;
                     }
                 } else {
@@ -564,28 +562,28 @@ pub unsafe fn dc_job_do_DC_JOB_IMEX_IMAP(context: &Context, job: *mut dc_job_t)
                             current_block = 10991094515395304355;
                             match current_block {
                                 2973387206439775448 => {
-                                    if 0 == import_backup(context, param1) {
+                                    if 0 == import_backup(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
                                     }
                                 }
                                 11250025114629486028 => {
-                                    if 0 == import_self_keys(context, param1) {
+                                    if 0 == import_self_keys(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
                                     }
                                 }
                                 12669919903773909120 => {
-                                    if 0 == export_backup(context, param1) {
+                                    if 0 == export_backup(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
                                     }
                                 }
                                 _ => {
-                                    if 0 == export_self_keys(context, param1) {
+                                    if 0 == export_self_keys(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
@@ -604,28 +602,28 @@ pub unsafe fn dc_job_do_DC_JOB_IMEX_IMAP(context: &Context, job: *mut dc_job_t)
                             current_block = 11250025114629486028;
                             match current_block {
                                 2973387206439775448 => {
-                                    if 0 == import_backup(context, param1) {
+                                    if 0 == import_backup(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
                                     }
                                 }
                                 11250025114629486028 => {
-                                    if 0 == import_self_keys(context, param1) {
+                                    if 0 == import_self_keys(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
                                     }
                                 }
                                 12669919903773909120 => {
-                                    if 0 == export_backup(context, param1) {
+                                    if 0 == export_backup(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
                                     }
                                 }
                                 _ => {
-                                    if 0 == export_self_keys(context, param1) {
+                                    if 0 == export_self_keys(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
@@ -644,28 +642,28 @@ pub unsafe fn dc_job_do_DC_JOB_IMEX_IMAP(context: &Context, job: *mut dc_job_t)
                             current_block = 12669919903773909120;
                             match current_block {
                                 2973387206439775448 => {
-                                    if 0 == import_backup(context, param1) {
+                                    if 0 == import_backup(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
                                     }
                                 }
                                 11250025114629486028 => {
-                                    if 0 == import_self_keys(context, param1) {
+                                    if 0 == import_self_keys(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
                                     }
                                 }
                                 12669919903773909120 => {
-                                    if 0 == export_backup(context, param1) {
+                                    if 0 == export_backup(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
                                     }
                                 }
                                 _ => {
-                                    if 0 == export_self_keys(context, param1) {
+                                    if 0 == export_self_keys(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
@@ -684,28 +682,28 @@ pub unsafe fn dc_job_do_DC_JOB_IMEX_IMAP(context: &Context, job: *mut dc_job_t)
                             current_block = 2973387206439775448;
                             match current_block {
                                 2973387206439775448 => {
-                                    if 0 == import_backup(context, param1) {
+                                    if 0 == import_backup(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
                                     }
                                 }
                                 11250025114629486028 => {
-                                    if 0 == import_self_keys(context, param1) {
+                                    if 0 == import_self_keys(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
                                     }
                                 }
                                 12669919903773909120 => {
-                                    if 0 == export_backup(context, param1) {
+                                    if 0 == export_backup(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
                                     }
                                 }
                                 _ => {
-                                    if 0 == export_self_keys(context, param1) {
+                                    if 0 == export_self_keys(context, param1.as_ptr()) {
                                         current_block = 3568988166330621280;
                                     } else {
                                         current_block = 1118134448028020070;
@@ -727,8 +725,6 @@ pub unsafe fn dc_job_do_DC_JOB_IMEX_IMAP(context: &Context, job: *mut dc_job_t)
         }
     }
 
-    free(param1 as *mut libc::c_void);
-    free(param2 as *mut libc::c_void);
     if 0 != ongoing_allocated_here {
         dc_free_ongoing(context);
     }
@@ -875,9 +871,8 @@ unsafe fn export_backup(context: &Context, dir: *const libc::c_char) -> libc::c_
     let res = chrono::NaiveDateTime::from_timestamp(now as i64, 0)
         .format("delta-chat-%Y-%m-%d.bak")
         .to_string();
-    let buffer = to_cstring(res);
+    let buffer = CString::yolo(res);
-    let dest_pathNfilename = dc_get_fine_pathNfilename(context, dir, buffer);
+    let dest_pathNfilename = dc_get_fine_pathNfilename(context, dir, buffer.as_ptr());
-    free(buffer as *mut _);
     if dest_pathNfilename.is_null() {
         error!(context, 0, "Cannot get backup file name.",);
 
@@ -1076,7 +1071,6 @@ unsafe fn import_self_keys(context: &Context, dir_name: *const libc::c_char) ->
     let mut imported_cnt: libc::c_int = 0;
     let mut suffix: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut path_plus_name: *mut libc::c_char = 0 as *mut libc::c_char;
-    let mut name_c: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut set_default: libc::c_int;
     let mut buf: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut buf_bytes: size_t = 0 as size_t;
@@ -1104,9 +1098,8 @@ unsafe fn import_self_keys(context: &Context, dir_name: *const libc::c_char) ->
                 let entry = entry.unwrap();
                 free(suffix as *mut libc::c_void);
                 let name_f = entry.file_name();
-                free(name_c as *mut libc::c_void);
+                let name_c = name_f.to_c_string().unwrap();
-                name_c = to_cstring(name_f.to_string_lossy());
+                suffix = dc_get_filesuffix_lc(name_c.as_ptr());
-                suffix = dc_get_filesuffix_lc(name_c);
                 if suffix.is_null()
                     || strcmp(suffix, b"asc\x00" as *const u8 as *const libc::c_char) != 0
                 {
@@ -1116,7 +1109,7 @@ unsafe fn import_self_keys(context: &Context, dir_name: *const libc::c_char) ->
                 path_plus_name = dc_mprintf(
                     b"%s/%s\x00" as *const u8 as *const libc::c_char,
                     dir_name,
-                    name_c,
+                    name_c.as_ptr(),
                 );
                 info!(context, 0, "Checking: {}", as_str(path_plus_name));
                 free(buf as *mut libc::c_void);
@@ -1154,7 +1147,12 @@ unsafe fn import_self_keys(context: &Context, dir_name: *const libc::c_char) ->
                     }
                 }
                 set_default = 1;
-                if !strstr(name_c, b"legacy\x00" as *const u8 as *const libc::c_char).is_null() {
+                if !strstr(
+                    name_c.as_ptr(),
+                    b"legacy\x00" as *const u8 as *const libc::c_char,
+                )
+                .is_null()
+                {
                     info!(
                         context,
                         0,
@@ -1179,7 +1177,6 @@ unsafe fn import_self_keys(context: &Context, dir_name: *const libc::c_char) ->
         }
     }
 
-    free(name_c as *mut libc::c_void);
     free(suffix as *mut libc::c_void);
     free(path_plus_name as *mut libc::c_void);
     free(buf as *mut libc::c_void);

src/dc_job.rs

@@ -314,7 +314,7 @@ unsafe fn dc_job_do_DC_JOB_SEND(context: &Context, job: &mut dc_job_t) {
     }
     match current_block {
         13109137661213826276 => {
-            filename = to_cstring(job.param.get(Param::File).unwrap_or_default());
+            filename = job.param.get(Param::File).unwrap_or_default().strdup();
             if strlen(filename) == 0 {
                 warn!(context, 0, "Missing file name for job {}", job.job_id,);
             } else if !(0 == dc_read_file(context, filename, &mut buf, &mut buf_bytes)) {
@@ -1177,12 +1177,11 @@ pub unsafe fn dc_job_send_msg(context: &Context, msg_id: uint32_t) -> libc::c_in
     } else {
         // no redo, no IMAP. moreover, as the data does not exist, there is no need in calling dc_set_msg_failed()
         if msgtype_has_file((*mimefactory.msg).type_0) {
-            let pathNfilename = to_cstring(
+            let pathNfilename = (*mimefactory.msg)
-                (*mimefactory.msg)
                 .param
                 .get(Param::File)
-                    .unwrap_or_default(),
+                .unwrap_or_default()
-            );
+                .strdup();
             if strlen(pathNfilename) > 0 {
                 if ((*mimefactory.msg).type_0 == Viewtype::Image
                     || (*mimefactory.msg).type_0 == Viewtype::Gif)

src/dc_location.rs

@@ -100,12 +100,9 @@ pub unsafe fn dc_send_locations_to_chat(
         {
             if 0 != seconds && !is_sending_locations_before {
                 msg = dc_msg_new(context, Viewtype::Text);
-                (*msg).text = to_cstring(context.stock_system_msg(
+                (*msg).text = context
-                    StockMessage::MsgLocationEnabled,
+                    .stock_system_msg(StockMessage::MsgLocationEnabled, "", "", 0)
-                    "",
+                    .strdup();
-                    "",
-                    0,
-                ));
                 (*msg).param.set_int(Param::Cmd, 8);
                 dc_send_msg(context, chat_id, msg);
             } else if 0 == seconds && is_sending_locations_before {
@@ -351,7 +348,7 @@ pub fn dc_get_location_kml(
     }
 
     if 0 != success {
-        unsafe { to_cstring(ret) }
+        unsafe { ret.strdup() }
     } else {
         std::ptr::null_mut()
     }
@@ -365,7 +362,7 @@ unsafe fn get_kml_timestamp(utc: i64) -> *mut libc::c_char {
     let res = chrono::NaiveDateTime::from_timestamp(utc, 0)
         .format("%Y-%m-%dT%H:%M:%SZ")
         .to_string();
-    to_cstring(res)
+    res.strdup()
 }
 
 pub unsafe fn dc_get_message_kml(

src/dc_lot.rs

@@ -134,14 +134,14 @@ pub unsafe fn dc_lot_fill(
         return;
     }
     if (*msg).state == 19i32 {
-        (*lot).text1 = to_cstring(context.stock_str(StockMessage::Draft));
+        (*lot).text1 = context.stock_str(StockMessage::Draft).strdup();
         (*lot).text1_meaning = 1i32
     } else if (*msg).from_id == 1i32 as libc::c_uint {
         if 0 != dc_msg_is_info(msg) || 0 != dc_chat_is_self_talk(chat) {
             (*lot).text1 = 0 as *mut libc::c_char;
             (*lot).text1_meaning = 0i32
         } else {
-            (*lot).text1 = to_cstring(context.stock_str(StockMessage::SelfMsg));
+            (*lot).text1 = context.stock_str(StockMessage::SelfMsg).strdup();
             (*lot).text1_meaning = 3i32
         }
     } else if chat.is_null() {

src/dc_mimefactory.rs

@@ -158,13 +158,13 @@ pub unsafe fn dc_mimefactory_load_msg(
                     |rows| {
                         for row in rows {
                             let (authname, addr) = row?;
-                            let addr_c = to_cstring(addr);
+                            let addr_c = addr.strdup();
                             if clist_search_string_nocase((*factory).recipients_addr, addr_c) == 0 {
                                 clist_insert_after(
                                     (*factory).recipients_names,
                                     (*(*factory).recipients_names).last,
                                     if !authname.is_empty() {
-                                        to_cstring(authname)
+                                        authname.strdup()
                                     } else {
                                         std::ptr::null_mut()
                                     } as *mut libc::c_void,
@@ -188,7 +188,7 @@ pub unsafe fn dc_mimefactory_load_msg(
 
             if command == 5 {
                 let email_to_remove = (*(*factory).msg).param.get(Param::Arg).unwrap_or_default();
-                let email_to_remove_c = to_cstring(email_to_remove);
+                let email_to_remove_c = email_to_remove.strdup();
 
                 let self_addr = context
                     .sql
@@ -234,8 +234,8 @@ pub unsafe fn dc_mimefactory_load_msg(
         );
         match row {
             Ok((in_reply_to, references)) => {
-                (*factory).in_reply_to = to_cstring(in_reply_to);
+                (*factory).in_reply_to = in_reply_to.strdup();
-                (*factory).references = to_cstring(references);
+                (*factory).references = references.strdup();
             }
             Err(err) => {
                 error!(
@@ -259,27 +259,28 @@ pub unsafe fn dc_mimefactory_load_msg(
 
 unsafe fn load_from(mut factory: *mut dc_mimefactory_t) {
     let context = (*factory).context;
-    (*factory).from_addr = to_cstring(
+    (*factory).from_addr = context
-        context
         .sql
         .get_config(context, "configured_addr")
-            .unwrap_or_default(),
+        .unwrap_or_default()
-    );
+        .strdup();
 
-    (*factory).from_displayname = to_cstring(
+    (*factory).from_displayname = context
-        context
         .sql
         .get_config(context, "displayname")
-            .unwrap_or_default(),
+        .unwrap_or_default()
-    );
+        .strdup();
-    (*factory).selfstatus = to_cstring(
+
-        context
+    (*factory).selfstatus = context
         .sql
         .get_config(context, "selfstatus")
-            .unwrap_or_default(),
+        .unwrap_or_default()
-    );
+        .strdup();
     if (*factory).selfstatus.is_null() {
-        (*factory).selfstatus = to_cstring((*factory).context.stock_str(StockMessage::StatusLine));
+        (*factory).selfstatus = (*factory)
+            .context
+            .stock_str(StockMessage::StatusLine)
+            .strdup();
     };
 }
 
@@ -573,8 +574,7 @@ pub unsafe fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_t) -> libc:
                     ),
                 );
                 if command == 5 {
-                    let email_to_remove =
+                    let email_to_remove = (*msg).param.get(Param::Arg).unwrap_or_default().strdup();
-                        to_cstring((*msg).param.get(Param::Arg).unwrap_or_default());
                     if strlen(email_to_remove) > 0 {
                         mailimf_fields_add(
                             imf_fields,
@@ -589,7 +589,7 @@ pub unsafe fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_t) -> libc:
                     }
                 } else if command == 4 {
                     do_gossip = 1;
-                    let email_to_add = to_cstring((*msg).param.get(Param::Arg).unwrap_or_default());
+                    let email_to_add = (*msg).param.get(Param::Arg).unwrap_or_default().strdup();
                     if strlen(email_to_add) > 0 {
                         mailimf_fields_add(
                             imf_fields,
@@ -619,7 +619,7 @@ pub unsafe fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_t) -> libc:
                         );
                     }
                 } else if command == 2 {
-                    let value_to_add = to_cstring((*msg).param.get(Param::Arg).unwrap_or_default());
+                    let value_to_add = (*msg).param.get(Param::Arg).unwrap_or_default().strdup();
                     mailimf_fields_add(
                         imf_fields,
                         mailimf_field_new_custom(
@@ -661,11 +661,13 @@ pub unsafe fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_t) -> libc:
                         strdup(b"v1\x00" as *const u8 as *const libc::c_char),
                     ),
                 );
-                placeholdertext =
+                placeholdertext = (*factory)
-                    to_cstring((*factory).context.stock_str(StockMessage::AcSetupMsgBody));
+                    .context
+                    .stock_str(StockMessage::AcSetupMsgBody)
+                    .strdup();
             }
             if command == 7 {
-                let step = to_cstring((*msg).param.get(Param::Arg).unwrap_or_default());
+                let step = (*msg).param.get(Param::Arg).unwrap_or_default().strdup();
                 if strlen(step) > 0 {
                     info!(
                         (*msg).context,
@@ -680,7 +682,7 @@ pub unsafe fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_t) -> libc:
                             step,
                         ),
                     );
-                    let param2 = to_cstring((*msg).param.get(Param::Arg2).unwrap_or_default());
+                    let param2 = (*msg).param.get(Param::Arg2).unwrap_or_default().strdup();
                     if strlen(param2) > 0 {
                         mailimf_fields_add(
                             imf_fields,
@@ -708,7 +710,7 @@ pub unsafe fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_t) -> libc:
                             ),
                         );
                     }
-                    let fingerprint = to_cstring((*msg).param.get(Param::Arg3).unwrap_or_default());
+                    let fingerprint = (*msg).param.get(Param::Arg3).unwrap_or_default().strdup();
                     if strlen(fingerprint) > 0 {
                         mailimf_fields_add(
                             imf_fields,
@@ -722,7 +724,7 @@ pub unsafe fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_t) -> libc:
                         );
                     }
                     let grpid = match (*msg).param.get(Param::Arg4) {
-                        Some(id) => to_cstring(id),
+                        Some(id) => id.strdup(),
                         None => std::ptr::null_mut(),
                     };
                     if !grpid.is_null() {
@@ -958,25 +960,23 @@ pub unsafe fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_t) -> libc:
                 ) as *mut libc::c_void,
             );
             mailmime_add_part(message, multipart);
-            let p1: *mut libc::c_char;
+            let p1 = if 0
-            let p2: *mut libc::c_char;
+                != (*(*factory).msg)
-            if 0 != (*(*factory).msg)
                     .param
                     .get_int(Param::GuranteeE2ee)
                     .unwrap_or_default()
             {
-                p1 = to_cstring((*factory).context.stock_str(StockMessage::EncryptedMsg));
-            } else {
-                p1 = dc_msg_get_summarytext((*factory).msg, 32)
-            }
-            p2 = to_cstring(
                 (*factory)
                     .context
-                    .stock_string_repl_str(StockMessage::ReadRcptMailBody, as_str(p1)),
+                    .stock_str(StockMessage::EncryptedMsg)
-            );
+                    .into_owned()
-            message_text = dc_mprintf(b"%s\r\n\x00" as *const u8 as *const libc::c_char, p2);
+            } else {
-            free(p1 as *mut libc::c_void);
+                to_string(dc_msg_get_summarytext((*factory).msg, 32))
-            free(p2 as *mut libc::c_void);
+            };
+            let p2 = (*factory)
+                .context
+                .stock_string_repl_str(StockMessage::ReadRcptMailBody, p1);
+            message_text = format!("{}\r\n", p2).strdup();
             let human_mime_part: *mut mailmime = build_body_text(message_text);
             mailmime_add_part(multipart, human_mime_part);
             message_text2 =
@@ -1102,7 +1102,7 @@ unsafe fn get_subject(
         b"\x00" as *const u8 as *const libc::c_char
     };
     if (*msg).param.get_int(Param::Cmd).unwrap_or_default() == 6 {
-        ret = to_cstring(context.stock_str(StockMessage::AcSetupMsgSubject))
+        ret = context.stock_str(StockMessage::AcSetupMsgSubject).strdup()
     } else if (*chat).type_0 == DC_CHAT_TYPE_GROUP as libc::c_int
         || (*chat).type_0 == DC_CHAT_TYPE_VERIFIED_GROUP as libc::c_int
     {
@@ -1165,12 +1165,12 @@ unsafe fn build_body_file(
     let pathNfilename = (*msg)
         .param
         .get(Param::File)
-        .map(|s| to_cstring(s))
+        .map(|s| s.strdup())
         .unwrap_or_else(|| std::ptr::null_mut());
     let mut mimetype = (*msg)
         .param
         .get(Param::MimeType)
-        .map(|s| to_cstring(s))
+        .map(|s| s.strdup())
         .unwrap_or_else(|| std::ptr::null_mut());
 
     let suffix = dc_get_filesuffix_lc(pathNfilename);
@@ -1189,7 +1189,7 @@ unsafe fn build_body_file(
             let res = ts
                 .format(&format!("voice-message_%Y-%m-%d_%H-%M-%S.{}", suffix))
                 .to_string();
-            filename_to_send = to_cstring(res);
+            filename_to_send = res.strdup();
         } else if (*msg).type_0 == Viewtype::Audio {
             filename_to_send = dc_get_filename(pathNfilename)
         } else if (*msg).type_0 == Viewtype::Image || (*msg).type_0 == Viewtype::Gif {
@@ -1329,7 +1329,7 @@ unsafe fn build_body_file(
 #[allow(non_snake_case)]
 unsafe fn is_file_size_okay(msg: *const dc_msg_t) -> bool {
     let mut file_size_okay = true;
-    let pathNfilename = to_cstring((*msg).param.get(Param::File).unwrap_or_default());
+    let pathNfilename = (*msg).param.get(Param::File).unwrap_or_default().strdup();
     let bytes = dc_get_filebytes((*msg).context, pathNfilename);
 
     if bytes > (49 * 1024 * 1024 / 4 * 3) {

src/dc_mimeparser.rs

@@ -1312,9 +1312,8 @@ unsafe fn dc_mimeparser_add_single_part_if_known(
                         }
                         if !filename_parts.is_empty() {
                             free(desired_filename as *mut libc::c_void);
-                            let parts_c = to_cstring(filename_parts);
+                            let parts_c = CString::yolo(filename_parts);
-                            desired_filename = dc_decode_ext_header(parts_c);
+                            desired_filename = dc_decode_ext_header(parts_c.as_ptr());
-                            free(parts_c as *mut _);
                         }
                         if desired_filename.is_null() {
                             let param = mailmime_find_ct_parameter(

src/dc_msg.rs

@@ -65,7 +65,7 @@ pub unsafe fn dc_get_msg_info(context: &Context, msg_id: u32) -> *mut libc::c_ch
         ret += &format!("Cannot load message #{}.", msg_id as usize);
         dc_msg_unref(msg);
         dc_contact_unref(contact_from);
-        return to_cstring(ret);
+        return ret.strdup();
     }
     let rawtxt = rawtxt.unwrap();
     let rawtxt = dc_truncate_str(rawtxt.trim(), 100000);
@@ -92,7 +92,7 @@ pub unsafe fn dc_get_msg_info(context: &Context, msg_id: u32) -> *mut libc::c_ch
         // device-internal message, no further details needed
         dc_msg_unref(msg);
         dc_contact_unref(contact_from);
-        return to_cstring(ret);
+        return ret.strdup();
     }
 
     context
@@ -210,7 +210,7 @@ pub unsafe fn dc_get_msg_info(context: &Context, msg_id: u32) -> *mut libc::c_ch
 
     dc_msg_unref(msg);
     dc_contact_unref(contact_from);
-    to_cstring(ret)
+    ret.strdup()
 }
 
 pub unsafe fn dc_msg_new_untyped<'a>(context: &'a Context) -> *mut dc_msg_t<'a> {
@@ -288,18 +288,17 @@ pub unsafe fn dc_msg_get_filemime(msg: *const dc_msg_t) -> *mut libc::c_char {
     if !(msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint) {
         match (*msg).param.get(Param::MimeType) {
             Some(m) => {
-                ret = to_cstring(m);
+                ret = m.strdup();
             }
             None => {
                 if let Some(file) = (*msg).param.get(Param::File) {
-                    let file_c = to_cstring(file);
+                    let file_c = CString::yolo(file);
-                    dc_msg_guess_msgtype_from_suffix(file_c, 0 as *mut Viewtype, &mut ret);
+                    dc_msg_guess_msgtype_from_suffix(file_c.as_ptr(), 0 as *mut Viewtype, &mut ret);
                     if ret.is_null() {
                         ret = dc_strdup(
                             b"application/octet-stream\x00" as *const u8 as *const libc::c_char,
                         )
                     }
-                    free(file_c as *mut _);
                 }
             }
         }
@@ -372,9 +371,8 @@ pub unsafe fn dc_msg_get_file(msg: *const dc_msg_t) -> *mut libc::c_char {
 
     if !(msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint) {
         if let Some(file_rel) = (*msg).param.get(Param::File) {
-            let file_rel_c = to_cstring(file_rel);
+            let file_rel_c = CString::yolo(file_rel);
-            file_abs = dc_get_abs_path((*msg).context, file_rel_c);
+            file_abs = dc_get_abs_path((*msg).context, file_rel_c.as_ptr());
-            free(file_rel_c as *mut _);
         }
     }
     if !file_abs.is_null() {
@@ -464,12 +462,12 @@ pub fn dc_msg_load_from_db<'a>(msg: *mut dc_msg_t<'a>, context: &'a Context, id:
                 dc_msg_empty(msg);
 
                 (*msg).id = row.get::<_, i32>(0)? as u32;
-                (*msg).rfc724_mid = to_cstring(row.get::<_, String>(1)?);
+                (*msg).rfc724_mid = row.get::<_, String>(1)?.strdup();
                 (*msg).in_reply_to = match row.get::<_, Option<String>>(2)? {
-                    Some(s) => to_cstring(s),
+                    Some(s) => s.strdup(),
                     None => std::ptr::null_mut(),
                 };
-                (*msg).server_folder = to_cstring(row.get::<_, String>(3)?);
+                (*msg).server_folder = row.get::<_, String>(3)?.strdup();
                 (*msg).server_uid = row.get(4)?;
                 (*msg).move_state = row.get(5)?;
                 (*msg).chat_id = row.get(6)?;
@@ -481,7 +479,7 @@ pub fn dc_msg_load_from_db<'a>(msg: *mut dc_msg_t<'a>, context: &'a Context, id:
                 (*msg).type_0 = row.get(12)?;
                 (*msg).state = row.get(13)?;
                 (*msg).is_dc_message = row.get(14)?;
-                (*msg).text = to_cstring(row.get::<_, String>(15).unwrap_or_default());
+                (*msg).text = row.get::<_, String>(15).unwrap_or_default().strdup();
                 (*msg).param = row.get::<_, String>(16)?.parse().unwrap_or_default();
                 (*msg).starred = row.get(17)?;
                 (*msg).hidden = row.get(18)?;
@@ -507,10 +505,8 @@ pub unsafe fn dc_get_mime_headers(context: &Context, msg_id: uint32_t) -> *mut l
     );
 
     if let Some(headers) = headers {
-        let h = to_cstring(headers);
+        let h = CString::yolo(headers);
-        let res = dc_strdup_keep_null(h);
+        dc_strdup_keep_null(h.as_ptr())
-        free(h as *mut _);
-        res
     } else {
         std::ptr::null_mut()
     }
@@ -711,7 +707,7 @@ pub unsafe fn dc_msg_get_text(msg: *const dc_msg_t) -> *mut libc::c_char {
     }
 
     let res = dc_truncate_str(as_str((*msg).text), 30000);
-    to_cstring(res)
+    res.strdup()
 }
 
 #[allow(non_snake_case)]
@@ -720,9 +716,8 @@ pub unsafe fn dc_msg_get_filename(msg: *const dc_msg_t) -> *mut libc::c_char {
 
     if !(msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint) {
         if let Some(file) = (*msg).param.get(Param::File) {
-            let file_c = to_cstring(file);
+            let file_c = CString::yolo(file);
-            ret = dc_get_filename(file_c);
+            ret = dc_get_filename(file_c.as_ptr());
-            free(file_c as *mut _);
         }
     }
     if !ret.is_null() {
@@ -737,9 +732,8 @@ pub unsafe fn dc_msg_get_filebytes(msg: *const dc_msg_t) -> uint64_t {
 
     if !(msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint) {
         if let Some(file) = (*msg).param.get(Param::File) {
-            let file_c = to_cstring(file);
+            let file_c = CString::yolo(file);
-            ret = dc_get_filebytes((*msg).context, file_c);
+            ret = dc_get_filebytes((*msg).context, file_c.as_ptr());
-            free(file_c as *mut _);
         }
     }
 
@@ -858,16 +852,19 @@ pub unsafe fn dc_msg_get_summarytext_by_raw(
     let mut value: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut append_text: libc::c_int = 1i32;
     match type_0 {
-        Viewtype::Image => prefix = to_cstring(context.stock_str(StockMessage::Image)),
+        Viewtype::Image => prefix = context.stock_str(StockMessage::Image).strdup(),
-        Viewtype::Gif => prefix = to_cstring(context.stock_str(StockMessage::Gif)),
+        Viewtype::Gif => prefix = context.stock_str(StockMessage::Gif).strdup(),
-        Viewtype::Video => prefix = to_cstring(context.stock_str(StockMessage::Video)),
+        Viewtype::Video => prefix = context.stock_str(StockMessage::Video).strdup(),
-        Viewtype::Voice => prefix = to_cstring(context.stock_str(StockMessage::VoiceMessage)),
+        Viewtype::Voice => prefix = context.stock_str(StockMessage::VoiceMessage).strdup(),
         Viewtype::Audio | Viewtype::File => {
             if param.get_int(Param::Cmd) == Some(6) {
-                prefix = to_cstring(context.stock_str(StockMessage::AcSetupMsgSubject));
+                prefix = context.stock_str(StockMessage::AcSetupMsgSubject).strdup();
                 append_text = 0i32
             } else {
-                pathNfilename = to_cstring(param.get(Param::File).unwrap_or_else(|| "ErrFilename"));
+                pathNfilename = param
+                    .get(Param::File)
+                    .unwrap_or_else(|| "ErrFilename")
+                    .strdup();
                 value = dc_get_filename(pathNfilename);
                 let label = CString::new(
                     context
@@ -888,7 +885,7 @@ pub unsafe fn dc_msg_get_summarytext_by_raw(
         }
         _ => {
             if param.get_int(Param::Cmd) == Some(9) {
-                prefix = to_cstring(context.stock_str(StockMessage::Location));
+                prefix = context.stock_str(StockMessage::Location).strdup();
                 append_text = 0;
             }
         }
@@ -1387,7 +1384,7 @@ pub fn dc_rfc724_mid_exists(
         &[as_str(rfc724_mid)],
         |row| {
             if !ret_server_folder.is_null() {
-                unsafe { *ret_server_folder = to_cstring(row.get::<_, String>(0)?) };
+                unsafe { *ret_server_folder = row.get::<_, String>(0)?.strdup() };
             }
             if !ret_server_uid.is_null() {
                 unsafe { *ret_server_uid = row.get(1)? };

src/dc_qr.rs

@@ -59,34 +59,34 @@ pub unsafe fn dc_check_qr(context: &Context, qr: *const libc::c_char) -> *mut dc
                 let param: Params = as_str(fragment).parse().expect("invalid params");
                 addr = param
                     .get(Param::Forwarded)
-                    .map(|s| to_cstring(s))
+                    .map(|s| s.strdup())
                     .unwrap_or_else(|| std::ptr::null_mut());
                 if !addr.is_null() {
                     if let Some(ref name_enc) = param.get(Param::SetLongitude) {
                         let name_r = percent_decode_str(name_enc)
                             .decode_utf8()
                             .expect("invalid name");
-                        name = to_cstring(name_r);
+                        name = name_r.strdup();
                         dc_normalize_name(name);
                     }
                     invitenumber = param
                         .get(Param::ProfileImage)
-                        .map(|s| to_cstring(s))
+                        .map(|s| s.strdup())
                         .unwrap_or_else(|| std::ptr::null_mut());
                     auth = param
                         .get(Param::Auth)
-                        .map(|s| to_cstring(s))
+                        .map(|s| s.strdup())
                         .unwrap_or_else(|| std::ptr::null_mut());
                     grpid = param
                         .get(Param::GroupId)
-                        .map(|s| to_cstring(s))
+                        .map(|s| s.strdup())
                         .unwrap_or_else(|| std::ptr::null_mut());
                     if !grpid.is_null() {
                         if let Some(grpname_enc) = param.get(Param::GroupName) {
                             let grpname_r = percent_decode_str(grpname_enc)
                                 .decode_utf8()
                                 .expect("invalid groupname");
-                            grpname = to_cstring(grpname_r);
+                            grpname = grpname_r.strdup();
                         }
                     }
                 }
@@ -253,7 +253,7 @@ pub unsafe fn dc_check_qr(context: &Context, qr: *const libc::c_char) -> *mut dc
                                         if let Some(peerstate) = peerstate {
                                             (*qr_parsed).state = 210i32;
                                             let addr_ptr = if let Some(ref addr) = peerstate.addr {
-                                                to_cstring(addr)
+                                                addr.strdup()
                                             } else {
                                                 std::ptr::null()
                                             };

src/dc_receive_imf.rs

@@ -1210,7 +1210,7 @@ unsafe fn create_or_lookup_group(
                                         grpimage = (*part)
                                             .param
                                             .get(Param::File)
-                                            .map(|s| to_cstring(s))
+                                            .map(|s| s.strdup())
                                             .unwrap_or_else(|| std::ptr::null_mut());
                                         ok = 1
                                     }
@@ -1407,10 +1407,12 @@ unsafe fn create_or_lookup_adhoc_group(
                             {
                                 grpname = dc_strdup(mime_parser.subject)
                             } else {
-                                grpname = to_cstring(context.stock_string_repl_int(
+                                grpname = context
+                                    .stock_string_repl_int(
                                         StockMessage::Member,
                                         dc_array_get_cnt(member_ids) as libc::c_int,
-                                ));
+                                    )
+                                    .strdup();
                             }
                             chat_id =
                                 create_group_record(context, grpid, grpname, create_blocked, 0);
@@ -1519,7 +1521,7 @@ fn hex_hash(s: impl AsRef<str>) -> *const libc::c_char {
     let bytes = s.as_ref().as_bytes();
     let result = Sha256::digest(bytes);
     let result_hex = hex::encode(&result[..8]);
-    unsafe { to_cstring(result_hex) as *const _ }
+    unsafe { result_hex.strdup() as *const _ }
 }
 
 #[allow(non_snake_case)]
@@ -1604,7 +1606,7 @@ unsafe fn check_verified_properties(
     let contact = dc_contact_new(context);
 
     let verify_fail = |reason: String| {
-        *failure_reason = to_cstring(format!("{}. See \"Info\" for details.", reason));
+        *failure_reason = format!("{}. See \"Info\" for details.", reason).strdup();
         warn!(context, 0, "{}", reason);
     };
 
@@ -1714,7 +1716,7 @@ unsafe fn set_better_msg<T: AsRef<str>>(mime_parser: &dc_mimeparser_t, better_ms
             carray_get(mime_parser.parts, 0 as libc::c_uint) as *mut dc_mimepart_t;
         if (*part).type_0 == 10 {
             free((*part).msg as *mut libc::c_void);
-            (*part).msg = to_cstring(msg);
+            (*part).msg = msg.strdup();
         }
     };
 }

src/dc_securejoin.rs

@@ -40,7 +40,7 @@ pub unsafe fn dc_get_securejoin_qr(
     let mut chat = 0 as *mut Chat;
     let mut group_name = 0 as *mut libc::c_char;
     let mut group_name_urlencoded = 0 as *mut libc::c_char;
-    let mut qr = None;
+    let mut qr: Option<String> = None;
 
     dc_ensure_secret_key_exists(context);
     invitenumber = dc_token_lookup(context, DC_TOKEN_INVITENUMBER, group_chat_id);
@@ -64,7 +64,7 @@ pub unsafe fn dc_get_securejoin_qr(
         free(group_name_urlencoded as *mut libc::c_void);
 
         if let Some(qr) = qr {
-            to_cstring(qr)
+            qr.strdup()
         } else {
             std::ptr::null_mut()
         }

src/dc_simplify.rs

@@ -229,7 +229,7 @@ impl dc_simplify_t {
         }
         dc_free_splitted_lines(lines);
 
-        to_cstring(ret)
+        ret.strdup()
     }
 }
 

src/dc_strencode.rs

@@ -1,4 +1,4 @@
-use std::ffi::CStr;
+use std::ffi::{CStr, CString};
 
 use charset::Charset;
 use mmime::mailmime_decode::*;
@@ -710,9 +710,8 @@ unsafe fn print_hex(target: *mut libc::c_char, cur: *const libc::c_char) {
     assert!(!cur.is_null());
 
     let bytes = std::slice::from_raw_parts(cur as *const _, strlen(cur));
-    let raw = to_cstring(format!("={}", &hex::encode_upper(bytes)[..2]));
+    let raw = CString::yolo(format!("={}", &hex::encode_upper(bytes)[..2]));
-    libc::memcpy(target as *mut _, raw as *const _, 4);
+    libc::memcpy(target as *mut _, raw.as_ptr() as *const _, 4);
-    free(raw as *mut libc::c_void);
 }
 
 #[cfg(test)]

src/dc_token.rs

@@ -42,7 +42,7 @@ pub fn dc_token_lookup(
             params![namespc as i32, foreign_id as i32],
             0,
         )
-        .map(|s| unsafe { to_cstring(s) })
+        .map(|s| unsafe { s.strdup() })
         .unwrap_or_else(|| std::ptr::null_mut())
 }
 

src/dc_tools.rs

@@ -178,14 +178,13 @@ pub unsafe fn dc_trim(buf: *mut libc::c_char) {
 
 /* the result must be free()'d */
 pub unsafe fn dc_strlower(in_0: *const libc::c_char) -> *mut libc::c_char {
-    to_cstring(to_string(in_0).to_lowercase())
+    to_string(in_0).to_lowercase().strdup()
 }
 
 pub unsafe fn dc_strlower_in_place(in_0: *mut libc::c_char) {
-    let raw = to_cstring(to_string(in_0).to_lowercase());
+    let raw = CString::yolo(to_string(in_0).to_lowercase());
-    assert_eq!(strlen(in_0), strlen(raw));
+    assert_eq!(strlen(in_0), strlen(raw.as_ptr()));
-    memcpy(in_0 as *mut _, raw as *const _, strlen(in_0));
+    memcpy(in_0 as *mut _, raw.as_ptr() as *const _, strlen(in_0));
-    free(raw as *mut _);
 }
 
 pub unsafe fn dc_str_contains(
@@ -233,7 +232,7 @@ pub unsafe fn dc_binary_to_uc_hex(buf: *const uint8_t, bytes: size_t) -> *mut li
 
     let buf = std::slice::from_raw_parts(buf, bytes);
     let raw = hex::encode_upper(buf);
-    to_cstring(raw)
+    raw.strdup()
 }
 
 /* remove all \r characters from string */
@@ -527,7 +526,7 @@ pub unsafe fn dc_str_from_clist(
         }
     }
 
-    to_cstring(res)
+    res.strdup()
 }
 
 pub unsafe fn dc_str_to_clist(
@@ -1236,10 +1235,8 @@ pub unsafe fn dc_write_file(
 #[allow(non_snake_case)]
 pub fn dc_write_file_safe(context: &Context, pathNfilename: impl AsRef<str>, buf: &[u8]) -> bool {
     let pathNfilename_abs = unsafe {
-        let n = to_cstring(pathNfilename.as_ref());
+        let n = CString::yolo(pathNfilename.as_ref());
-        let res = dc_get_abs_path(context, n);
+        dc_get_abs_path(context, n.as_ptr())
-        free(n as *mut _);
-        res
     };
     if pathNfilename_abs.is_null() {
         return false;
@@ -1287,10 +1284,8 @@ pub unsafe fn dc_read_file(
 #[allow(non_snake_case)]
 pub fn dc_read_file_safe(context: &Context, pathNfilename: impl AsRef<str>) -> Option<Vec<u8>> {
     let pathNfilename_abs = unsafe {
-        let n = to_cstring(pathNfilename.as_ref());
+        let n = CString::yolo(pathNfilename.as_ref());
-        let p = dc_get_abs_path(context, n);
+        dc_get_abs_path(context, n.as_ptr())
-        free(n as *mut _);
-        p
     };
 
     if pathNfilename_abs.is_null() {
@@ -1523,6 +1518,51 @@ fn os_str_to_c_string_unicode(
     }
 }
 
+/// Convenience methods/associated functions for working with [CString]
+///
+/// This is helps transitioning from unsafe code.
+pub trait CStringExt {
+    /// Create a new [CString], yolo style
+    ///
+    /// This unwrap the result, panicking when there are embedded NULL
+    /// bytes.
+    fn yolo<T: Into<Vec<u8>>>(t: T) -> CString {
+        CString::new(t).expect("String contains null byte, can not be CString")
+    }
+}
+
+impl CStringExt for CString {}
+
+/// Convenience methods to make transitioning from raw C strings easier.
+///
+/// To interact with (legacy) C APIs we often need to convert from
+/// Rust strings to raw C strings.  This can be clumsy to do correctly
+/// and the compiler sometimes allows it in an unsafe way.  These
+/// methods make it more succinct and help you get it right.
+pub trait StrExt {
+    /// Allocate a new raw C `*char` version of this string.
+    ///
+    /// This allocates a new raw C string which must be freed using
+    /// `free`.  It takes care of some common pitfalls with using
+    /// [CString::as_ptr].
+    ///
+    /// [CString::as_ptr]: std::ffi::CString::as_ptr
+    ///
+    /// # Panics
+    ///
+    /// This function will panic when the original string contains an
+    /// interior null byte as this can not be represented in raw C
+    /// strings.
+    unsafe fn strdup(&self) -> *mut libc::c_char;
+}
+
+impl<T: AsRef<str>> StrExt for T {
+    unsafe fn strdup(&self) -> *mut libc::c_char {
+        let tmp = CString::yolo(self.as_ref());
+        dc_strdup(tmp.as_ptr())
+    }
+}
+
 /// Needs to free the result after use!
 pub unsafe fn to_cstring<S: AsRef<str>>(s: S) -> *mut libc::c_char {
     let cstr = CString::new(s.as_ref()).expect("invalid string converted");
@@ -2085,4 +2125,29 @@ mod tests {
         let ptr = some_path.as_ptr();
         assert_eq!(as_path_unicode(ptr), std::ffi::OsString::from("/some/path"));
     }
+
+    #[test]
+    fn test_cstring_yolo() {
+        assert_eq!(CString::new("hello").unwrap(), CString::yolo("hello"));
+    }
+
+    #[test]
+    fn test_strdup_str() {
+        unsafe {
+            let s = "hello".strdup();
+            let cmp = strcmp(s, b"hello\x00" as *const u8 as *const libc::c_char);
+            free(s as *mut libc::c_void);
+            assert_eq!(cmp, 0);
+        }
+    }
+
+    #[test]
+    fn test_strdup_string() {
+        unsafe {
+            let s = String::from("hello").strdup();
+            let cmp = strcmp(s, b"hello\x00" as *const u8 as *const libc::c_char);
+            free(s as *mut libc::c_void);
+            assert_eq!(cmp, 0);
+        }
+    }
 }

src/imap.rs

@@ -1,3 +1,4 @@
+use std::ffi::CString;
 use std::net;
 use std::sync::{Arc, Condvar, Mutex, RwLock};
 use std::time::{Duration, SystemTime};
@@ -5,10 +6,9 @@ use std::time::{Duration, SystemTime};
 use crate::constants::*;
 use crate::context::Context;
 use crate::dc_loginparam::*;
-use crate::dc_tools::to_cstring;
+use crate::dc_tools::CStringExt;
 use crate::oauth2::dc_get_oauth2_access_token;
 use crate::types::*;
-use crate::x::free;
 
 pub const DC_IMAP_SEEN: usize = 0x0001;
 pub const DC_REGENERATE: usize = 0x01;
@@ -843,10 +843,8 @@ impl Imap {
                     .expect("missing message id");
 
                 if 0 == unsafe {
-                    let message_id_c = to_cstring(message_id);
+                    let message_id_c = CString::yolo(message_id);
-                    let res = (self.precheck_imf)(context, message_id_c, folder.as_ref(), cur_uid);
+                    (self.precheck_imf)(context, message_id_c.as_ptr(), folder.as_ref(), cur_uid)
-                    free(message_id_c as *mut _);
-                    res
                 } {
                     // check passed, go fetch the rest
                     if self.fetch_single_msg(context, &folder, cur_uid) == 0 {

src/log.rs

@@ -7,10 +7,9 @@ macro_rules! info {
         #[allow(unused_unsafe)]
         unsafe {
             let formatted = format!($msg, $($args),*);
-            let formatted_c =  $crate::dc_tools::to_cstring(formatted);
+            let formatted_c =  std::ffi::CString::new(formatted).unwrap();
             $ctx.call_cb($crate::constants::Event::INFO, $data1 as libc::uintptr_t,
-                     formatted_c as libc::uintptr_t);
+                     formatted_c.as_ptr() as libc::uintptr_t);
-            libc::free(formatted_c as *mut libc::c_void);
     }};
 }
 
@@ -23,10 +22,9 @@ macro_rules! warn {
         #[allow(unused_unsafe)]
         unsafe {
             let formatted = format!($msg, $($args),*);
-            let formatted_c = $crate::dc_tools::to_cstring(formatted);
+            let formatted_c = std::ffi::CString::new(formatted).unwrap();
             $ctx.call_cb($crate::constants::Event::WARNING, $data1 as libc::uintptr_t,
-                         formatted_c as libc::uintptr_t);
+                         formatted_c.as_ptr() as libc::uintptr_t);
-            libc::free(formatted_c as *mut libc::c_void) ;
         }};
 }
 
@@ -39,10 +37,9 @@ macro_rules! error {
         #[allow(unused_unsafe)]
         unsafe {
         let formatted = format!($msg, $($args),*);
-        let formatted_c = $crate::dc_tools::to_cstring(formatted);
+        let formatted_c = std::ffi::CString::new(formatted).unwrap();
         $ctx.call_cb($crate::constants::Event::ERROR, $data1 as libc::uintptr_t,
-                     formatted_c as libc::uintptr_t);
+                     formatted_c.as_ptr() as libc::uintptr_t);
-        libc::free(formatted_c as *mut libc::c_void);
     }};
 }
 
@@ -55,9 +52,8 @@ macro_rules! log_event {
         #[allow(unused_unsafe)]
         unsafe {
             let formatted = format!($msg, $($args),*);
-            let formatted_c = $crate::dc_tools::to_cstring(formatted);
+            let formatted_c = std::ffi::CString::new(formatted).unwrap();
             $ctx.call_cb($event, $data1 as libc::uintptr_t,
-                         formatted_c as libc::uintptr_t);
+                         formatted_c.as_ptr() as libc::uintptr_t);
-            libc::free(formatted_c as *mut libc::c_void);
     }};
 }

src/peerstate.rs

@@ -462,13 +462,11 @@ mod tests {
     use super::*;
     use pretty_assertions::assert_eq;
 
-    use tempfile::{tempdir, TempDir};
+    use tempfile::TempDir;
-
-    use crate::context::*;
 
     #[test]
     fn test_peerstate_save_to_db() {
-        let ctx = unsafe { create_test_context() };
+        let ctx = crate::test_utils::dummy_context();
         let addr = "hello@mail.com";
 
         let pub_key = crate::key::Key::from_base64("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", KeyType::Public).unwrap();
@@ -506,26 +504,4 @@ mod tests {
         ctx: Context,
         dir: TempDir,
     }
-
-    unsafe extern "C" fn cb(
-        _context: &Context,
-        _event: Event,
-        _data1: libc::uintptr_t,
-        _data2: libc::uintptr_t,
-    ) -> libc::uintptr_t {
-        0
-    }
-
-    unsafe fn create_test_context() -> TestContext {
-        let mut ctx = dc_context_new(Some(cb), std::ptr::null_mut(), None);
-        let dir = tempdir().unwrap();
-        let dbfile = dir.path().join("db.sqlite");
-        assert!(
-            dc_open(&mut ctx, dbfile.to_str().unwrap(), None),
-            "Failed to open {}",
-            dbfile.to_str().unwrap()
-        );
-
-        TestContext { ctx: ctx, dir: dir }
-    }
 }

src/sql.rs

@@ -10,7 +10,6 @@ use crate::dc_tools::*;
 use crate::error::{Error, Result};
 use crate::param::*;
 use crate::peerstate::*;
-use crate::x::*;
 
 const DC_OPEN_READONLY: usize = 0x01;
 
@@ -1049,9 +1048,8 @@ pub fn housekeeping(context: &Context) {
                     entry.file_name()
                 );
                 unsafe {
-                    let path = to_cstring(entry.path().to_str().unwrap());
+                    let path = entry.path().to_c_string().unwrap();
-                    dc_delete_file(context, path);
+                    dc_delete_file(context, path.as_ptr());
-                    free(path as *mut _);
                 }
             }
         }

tests/stress.rs

@@ -671,7 +671,7 @@ fn test_encryption_decryption() {
         assert!(ctext.starts_with("-----BEGIN PGP MESSAGE-----"));
 
         let ctext_signed_bytes = ctext.len();
-        let ctext_signed = to_cstring(ctext);
+        let ctext_signed = CString::yolo(ctext);
 
         let ctext = dc_pgp_pk_encrypt(
             original_text as *const libc::c_void,
@@ -684,7 +684,7 @@ fn test_encryption_decryption() {
         assert!(ctext.starts_with("-----BEGIN PGP MESSAGE-----"));
 
         let ctext_unsigned_bytes = ctext.len();
-        let ctext_unsigned = to_cstring(ctext);
+        let ctext_unsigned = CString::yolo(ctext);
 
         let mut keyring = Keyring::default();
         keyring.add_owned(private_key);
@@ -698,7 +698,7 @@ fn test_encryption_decryption() {
         let mut valid_signatures: HashSet<String> = Default::default();
 
         let plain = dc_pgp_pk_decrypt(
-            ctext_signed as *const _,
+            ctext_signed.as_ptr() as *const _,
             ctext_signed_bytes,
             &keyring,
             &public_keyring,
@@ -713,7 +713,7 @@ fn test_encryption_decryption() {
 
         let empty_keyring = Keyring::default();
         let plain = dc_pgp_pk_decrypt(
-            ctext_signed as *const _,
+            ctext_signed.as_ptr() as *const _,
             ctext_signed_bytes,
             &keyring,
             &empty_keyring,
@@ -726,7 +726,7 @@ fn test_encryption_decryption() {
         valid_signatures.clear();
 
         let plain = dc_pgp_pk_decrypt(
-            ctext_signed as *const _,
+            ctext_signed.as_ptr() as *const _,
             ctext_signed_bytes,
             &keyring,
             &public_keyring2,
@@ -741,7 +741,7 @@ fn test_encryption_decryption() {
         public_keyring2.add_ref(&public_key);
 
         let plain = dc_pgp_pk_decrypt(
-            ctext_signed as *const _,
+            ctext_signed.as_ptr() as *const _,
             ctext_signed_bytes,
             &keyring,
             &public_keyring2,
@@ -754,7 +754,7 @@ fn test_encryption_decryption() {
         valid_signatures.clear();
 
         let plain = dc_pgp_pk_decrypt(
-            ctext_unsigned as *const _,
+            ctext_unsigned.as_ptr() as *const _,
             ctext_unsigned_bytes,
             &keyring,
             &public_keyring,
@@ -762,7 +762,6 @@ fn test_encryption_decryption() {
         )
         .unwrap();
 
-        free(ctext_unsigned as *mut _);
         assert_eq!(std::str::from_utf8(&plain).unwrap(), as_str(original_text),);
 
         valid_signatures.clear();
@@ -773,7 +772,7 @@ fn test_encryption_decryption() {
         public_keyring.add_ref(&public_key);
 
         let plain = dc_pgp_pk_decrypt(
-            ctext_signed as *const _,
+            ctext_signed.as_ptr() as *const _,
             ctext_signed_bytes,
             &keyring,
             &public_keyring,
@@ -781,7 +780,6 @@ fn test_encryption_decryption() {
         )
         .unwrap();
 
-        free(ctext_signed as *mut _);
         assert_eq!(std::str::from_utf8(&plain).unwrap(), as_str(original_text),);
     }
 }
@@ -808,7 +806,7 @@ unsafe fn create_test_context() -> TestContext {
     assert!(
         dc_open(&mut ctx, dbfile.to_str().unwrap(), None),
         "Failed to open {}",
-        dbfile.to_str().unwrap()
+        dbfile.display()
     );
     TestContext { ctx: ctx, dir: dir }
 }
@@ -931,29 +929,24 @@ fn test_stress_tests() {
 fn test_get_contacts() {
     unsafe {
         let context = create_test_context();
-        let name = to_cstring("some2");
+        let name = CString::yolo("some2");
-        let contacts = dc_get_contacts(&context.ctx, 0, name);
+        let contacts = dc_get_contacts(&context.ctx, 0, name.as_ptr());
         assert_eq!(dc_array_get_cnt(contacts), 0);
         dc_array_unref(contacts);
-        free(name as *mut _);
 
-        let name = to_cstring("bob");
+        let name = CString::yolo("bob");
-        let email = to_cstring("bob@mail.de");
+        let email = CString::yolo("bob@mail.de");
-        let id = dc_create_contact(&context.ctx, name, email);
+        let id = dc_create_contact(&context.ctx, name.as_ptr(), email.as_ptr());
         assert_ne!(id, 0);
 
-        let contacts = dc_get_contacts(&context.ctx, 0, name);
+        let contacts = dc_get_contacts(&context.ctx, 0, name.as_ptr());
         assert_eq!(dc_array_get_cnt(contacts), 1);
         dc_array_unref(contacts);
 
-        let name2 = to_cstring("alice");
+        let name2 = CString::yolo("alice");
-        let contacts = dc_get_contacts(&context.ctx, 0, name2);
+        let contacts = dc_get_contacts(&context.ctx, 0, name2.as_ptr());
         assert_eq!(dc_array_get_cnt(contacts), 0);
         dc_array_unref(contacts);
-
-        free(name as *mut _);
-        free(name2 as *mut _);
-        free(email as *mut _);
     }
 }
 
@@ -961,12 +954,10 @@ fn test_get_contacts() {
 fn test_chat() {
     unsafe {
         let context = create_test_context();
-        let name = to_cstring("bob");
+        let name = CString::yolo("bob");
-        let email = to_cstring("bob@mail.de");
+        let email = CString::yolo("bob@mail.de");
 
-        let contact1 = dc_create_contact(&context.ctx, name, email);
+        let contact1 = dc_create_contact(&context.ctx, name.as_ptr(), email.as_ptr());
-        free(name as *mut _);
-        free(email as *mut _);
         assert_ne!(contact1, 0);
 
         let chat_id = dc_create_chat_by_contact_id(&context.ctx, contact1);