display failed messages

This is an additional fix for #768 aka
commit eac8ad8369

ci_scripts/run-python.sh

@@ -43,8 +43,8 @@ if [ -n "$TESTS" ]; then
     # we split out qr-tests run to minimize likelyness of flaky tests
     # (some qr tests are pretty heavy in terms of send/received
     # messages and rust's imap code likely has concurrency problems) 
-    tox --workdir "$TOXWORKDIR" -e py37 -- -k "not qr"
-    tox --workdir "$TOXWORKDIR" -e py37 -- -k "qr"
+    tox --workdir "$TOXWORKDIR" -e py37 -- --reruns 3 -k "not qr"
+    tox --workdir "$TOXWORKDIR" -e py37 -- --reruns 3 -k "qr"
     unset DCC_PY_LIVECONFIG
     tox --workdir "$TOXWORKDIR" -p4 -e lint,py35,py36,doc
     tox --workdir "$TOXWORKDIR" -e auditwheels

deltachat-ffi/deltachat.h

@@ -338,6 +338,8 @@ char*           dc_get_blobdir               (const dc_context_t* context);
  * - `send_pw`      = SMTP-password, guessed if left out
  * - `send_port`    = SMTP-port, guessed if left out
  * - `server_flags` = IMAP-/SMTP-flags as a combination of @ref DC_LP flags, guessed if left out
+ * - `imap_certificate_checks` = how to check IMAP certificates, one of the @ref DC_CERTCK flags, defaults to #DC_CERTCK_AUTO (0)
+ * - `smtp_certificate_checks` = how to check SMTP certificates, one of the @ref DC_CERTCK flags, defaults to #DC_CERTCK_AUTO (0)
  * - `displayname`  = Own name to use when sending messages.  MUAs are allowed to spread this way eg. using CC, defaults to empty
  * - `selfstatus`   = Own status to display eg. in email footers, defaults to a standard text
  * - `selfavatar`   = File containing avatar. Will be copied to blob directory.
@@ -2610,8 +2612,6 @@ int             dc_chat_get_type             (const dc_chat_t* chat);
  *
  * To change the name, use dc_set_chat_name()
  *
- * See also: dc_chat_get_subtitle()
- *
  * @memberof dc_chat_t
  * @param chat The chat object.
  * @return Chat name as a string. Must be released using dc_str_unref() after usage. Never NULL.
@@ -2619,13 +2619,13 @@ int             dc_chat_get_type             (const dc_chat_t* chat);
 char*           dc_chat_get_name             (const dc_chat_t* chat);
 
 
-/**
+/*
  * Get a subtitle for a chat.  The subtitle is eg. the email-address or the
  * number of group members.
  *
- * See also: dc_chat_get_name()
+ * Deprecated function. Subtitles should be created in the ui
+ * where plural forms and other specials can be handled more gracefully.
  *
- * @memberof dc_chat_t
  * @param chat The chat object to calulate the subtitle for.
  * @return Subtitle as a string. Must be released using dc_str_unref() after usage. Never NULL.
  */
@@ -3894,7 +3894,7 @@ int64_t          dc_lot_get_timestamp     (const dc_lot_t* lot);
  *
  * These constants configure TLS certificate checks for IMAP and SMTP connections.
  *
- * These constants are set via dc_set_config
+ * These constants are set via dc_set_config()
  * using keys "imap_certificate_checks" and "smtp_certificate_checks".
  *
  * @addtogroup DC_CERTCK
@@ -3907,8 +3907,8 @@ int64_t          dc_lot_get_timestamp     (const dc_lot_t* lot);
 #define DC_CERTCK_AUTO 0
 
 /**
- * Strictly check TLS certificates.
- * Require that both the certificate and hostname are valid.
+ * Strictly check TLS certificates;
+ * require that both the certificate and hostname are valid.
  */
 #define DC_CERTCK_STRICT 1
 

deltachat-ffi/src/providers.rs

@@ -2,7 +2,7 @@ extern crate deltachat_provider_database;
 
 use std::ptr;
 
-use deltachat::dc_tools::{as_str, StrExt};
+use deltachat::dc_tools::{to_string_lossy, StrExt};
 use deltachat_provider_database::StatusState;
 
 #[no_mangle]
@@ -12,7 +12,7 @@ pub type dc_provider_t = deltachat_provider_database::Provider;
 pub unsafe extern "C" fn dc_provider_new_from_domain(
     domain: *const libc::c_char,
 ) -> *const dc_provider_t {
-    match deltachat_provider_database::get_provider_info(as_str(domain)) {
+    match deltachat_provider_database::get_provider_info(&to_string_lossy(domain)) {
         Some(provider) => provider,
         None => ptr::null(),
     }
@@ -22,7 +22,8 @@ pub unsafe extern "C" fn dc_provider_new_from_domain(
 pub unsafe extern "C" fn dc_provider_new_from_email(
     email: *const libc::c_char,
 ) -> *const dc_provider_t {
-    let domain = deltachat_provider_database::get_domain_from_email(as_str(email));
+    let email = to_string_lossy(email);
+    let domain = deltachat_provider_database::get_domain_from_email(&email);
     match deltachat_provider_database::get_provider_info(domain) {
         Some(provider) => provider,
         None => ptr::null(),

examples/repl/cmdline.rs

@@ -517,15 +517,13 @@ pub unsafe fn dc_cmdline(context: &Context, line: &str) -> Result<(), failure::E
 
                 for i in (0..cnt).rev() {
                     let chat = Chat::load_from_db(context, chatlist.get_chat_id(i))?;
-                    let temp_subtitle = chat.get_subtitle(context);
                     let temp_name = chat.get_name();
                     info!(
                         context,
-                        "{}#{}: {} [{}] [{} fresh]",
+                        "{}#{}: {} [{} fresh]",
                         chat_prefix(&chat),
                         chat.get_id(),
                         temp_name,
-                        temp_subtitle,
                         chat::get_fresh_msg_cnt(context, chat.get_id()),
                     );
                     let lot = chatlist.get_summary(context, i, Some(&chat));
@@ -583,7 +581,13 @@ pub unsafe fn dc_cmdline(context: &Context, line: &str) -> Result<(), failure::E
             let sel_chat = sel_chat.as_ref().unwrap();
 
             let msglist = chat::get_chat_msgs(context, sel_chat.get_id(), 0x1, None);
-            let temp2 = sel_chat.get_subtitle(context);
+            let members = chat::get_chat_contacts(context, sel_chat.id);
+            let temp2 = if sel_chat.get_type() == Chattype::Single && members.len() >= 1 {
+                let contact = Contact::get_by_id(context, members[0])?;
+                contact.get_addr().to_string()
+            } else {
+                format!("{} member(s)", members.len())
+            };
             let temp_name = sel_chat.get_name();
             info!(
                 context,

src/blob.rs

@@ -1,3 +1,4 @@
+use std::ffi::OsStr;
 use std::fmt;
 use std::fs;
 use std::io::Write;
@@ -145,6 +146,9 @@ impl<'a> BlobObject<'a> {
             .as_ref()
             .strip_prefix(context.get_blobdir())
             .map_err(|_| BlobError::new_wrong_blobdir(context.get_blobdir(), path.as_ref()))?;
+        if !BlobObject::is_acceptible_blob_name(&rel_path) {
+            return Err(BlobError::new_wrong_name(path.as_ref()));
+        }
         let name = rel_path
             .to_str()
             .ok_or_else(|| BlobError::new_wrong_name(path.as_ref()))?;
@@ -171,8 +175,7 @@ impl<'a> BlobObject<'a> {
             true => name.splitn(2, '/').last().unwrap().to_string(),
             false => name,
         };
-        let (stem, ext) = BlobObject::sanitise_name(name.clone());
-        if format!("{}{}", stem, ext) != name.as_ref() {
+        if !BlobObject::is_acceptible_blob_name(&name) {
             return Err(BlobError::new_wrong_name(name));
         }
         Ok(BlobObject {
@@ -266,6 +269,28 @@ impl<'a> BlobObject<'a> {
             _ => (stem, format!(".{}", ext).to_lowercase()),
         }
     }
+
+    /// Checks whether a name is a valid blob name.
+    ///
+    /// This is slightly less strict than stanitise_name, presumably
+    /// someone already created a file with such a name so we just
+    /// ensure it's not actually a path in disguise is actually utf-8.
+    fn is_acceptible_blob_name(name: impl AsRef<OsStr>) -> bool {
+        let uname = match name.as_ref().to_str() {
+            Some(name) => name,
+            None => return false,
+        };
+        if uname.find('/').is_some() {
+            return false;
+        }
+        if uname.find('\\').is_some() {
+            return false;
+        }
+        if uname.find('\0').is_some() {
+            return false;
+        }
+        true
+    }
 }
 
 impl<'a> fmt::Display for BlobObject<'a> {
@@ -615,4 +640,14 @@ mod tests {
             "$BLOBDIR/autocrypt-setup-message-4137848473.html"
         );
     }
+
+    #[test]
+    fn test_is_blob_name() {
+        assert!(BlobObject::is_acceptible_blob_name("foo"));
+        assert!(BlobObject::is_acceptible_blob_name("foo.txt"));
+        assert!(BlobObject::is_acceptible_blob_name("f".repeat(128)));
+        assert!(!BlobObject::is_acceptible_blob_name("foo/bar"));
+        assert!(!BlobObject::is_acceptible_blob_name("foo\\bar"));
+        assert!(!BlobObject::is_acceptible_blob_name("foo\x00bar"));
+    }
 }

src/dc_mimeparser.rs

@@ -117,18 +117,30 @@ impl<'a> MimeParser<'a> {
         );
 
         if r == MAILIMF_NO_ERROR as libc::c_int && !self.mimeroot.is_null() {
-            let (encrypted, signatures, gossipped_addr) =
-                e2ee::try_decrypt(self.context, self.mimeroot)?;
-            self.encrypted = encrypted;
-            self.signatures = signatures;
-            self.gossipped_addr = gossipped_addr;
+            match e2ee::try_decrypt(self.context, self.mimeroot) {
+                Ok((encrypted, signatures, gossipped_addr)) => {
+                    self.encrypted = encrypted;
+                    self.signatures = signatures;
+                    self.gossipped_addr = gossipped_addr;
+                }
+                Err(err) => {
+                    // continue with the current, still encrypted, mime tree.
+                    // unencrypted parts will be replaced by an error message
+                    // that is added as "the message" to the chat then.
+                    //
+                    // if we just return here, the header is missing
+                    // and the caller cannot display the message
+                    // and try to assign the message to a chat
+                    warn!(self.context, "decryption failed: {}", err);
+                }
+            }
+
             self.parse_mime_recursive(self.mimeroot);
 
             if let Some(field) = self.lookup_field("Subject") {
                 if (*field).fld_type == MAILIMF_FIELD_SUBJECT as libc::c_int {
                     let subj = (*(*field).fld_data.fld_subject).sbj_value;
-
-                    self.subject = as_opt_str(subj).map(dc_decode_header_words);
+                    self.subject = to_opt_string_lossy(subj).map(|x| dc_decode_header_words(&x));
                 }
             }
 
@@ -630,7 +642,7 @@ impl<'a> MimeParser<'a> {
                             self.context,
                             "Cannot convert {} bytes from \"{}\" to \"utf-8\".",
                             decoded_data.len(),
-                            as_str(charset),
+                            to_string_lossy(charset),
                         );
                     }
                 }
@@ -729,8 +741,10 @@ impl<'a> MimeParser<'a> {
                     if !(*mime).mm_content_type.is_null()
                         && !(*(*mime).mm_content_type).ct_subtype.is_null()
                     {
-                        desired_filename =
-                            format!("file.{}", as_str((*(*mime).mm_content_type).ct_subtype));
+                        desired_filename = format!(
+                            "file.{}",
+                            to_string_lossy((*(*mime).mm_content_type).ct_subtype)
+                        );
                     } else {
                         return false;
                     }
@@ -850,7 +864,8 @@ impl<'a> MimeParser<'a> {
             }) as *mut mailimf_mailbox;
 
             if !mb.is_null() {
-                let from_addr_norm = addr_normalize(as_str((*mb).mb_addr_spec));
+                let from_addr = to_string_lossy((*mb).mb_addr_spec);
+                let from_addr_norm = addr_normalize(&from_addr);
                 let recipients = wrapmime::mailimf_get_recipients(self.header_root);
                 if recipients.len() == 1 && recipients.contains(from_addr_norm) {
                     sender_equals_recipient = true;
@@ -989,15 +1004,16 @@ unsafe fn mailmime_get_mime_type(mime: *mut Mailmime) -> (libc::c_int, Viewtype,
                     }
                 }
 
-                let raw_mime = reconcat_mime(Some("text"), as_opt_str((*c).ct_subtype));
+                let raw_mime = reconcat_mime(Some("text"), to_opt_string_lossy((*c).ct_subtype));
                 (DC_MIMETYPE_FILE, Viewtype::File, Some(raw_mime))
             }
             MAILMIME_DISCRETE_TYPE_IMAGE => {
-                let subtype = as_opt_str((*c).ct_subtype);
-                let msg_type = match subtype {
+                let subtype = to_opt_string_lossy((*c).ct_subtype);
+                let msg_type = match subtype.as_ref().map(|x| x.as_str()) {
                     Some("gif") => Viewtype::Gif,
                     Some("svg+xml") => {
-                        let raw_mime = reconcat_mime(Some("image"), as_opt_str((*c).ct_subtype));
+                        let raw_mime =
+                            reconcat_mime(Some("image"), to_opt_string_lossy((*c).ct_subtype));
                         return (DC_MIMETYPE_FILE, Viewtype::File, Some(raw_mime));
                     }
                     _ => Viewtype::Image,
@@ -1007,11 +1023,11 @@ unsafe fn mailmime_get_mime_type(mime: *mut Mailmime) -> (libc::c_int, Viewtype,
                 (DC_MIMETYPE_IMAGE, msg_type, Some(raw_mime))
             }
             MAILMIME_DISCRETE_TYPE_AUDIO => {
-                let raw_mime = reconcat_mime(Some("audio"), as_opt_str((*c).ct_subtype));
+                let raw_mime = reconcat_mime(Some("audio"), to_opt_string_lossy((*c).ct_subtype));
                 (DC_MIMETYPE_AUDIO, Viewtype::Audio, Some(raw_mime))
             }
             MAILMIME_DISCRETE_TYPE_VIDEO => {
-                let raw_mime = reconcat_mime(Some("video"), as_opt_str((*c).ct_subtype));
+                let raw_mime = reconcat_mime(Some("video"), to_opt_string_lossy((*c).ct_subtype));
                 (DC_MIMETYPE_VIDEO, Viewtype::Video, Some(raw_mime))
             }
             _ => {
@@ -1022,13 +1038,15 @@ unsafe fn mailmime_get_mime_type(mime: *mut Mailmime) -> (libc::c_int, Viewtype,
                         b"autocrypt-setup\x00" as *const u8 as *const libc::c_char,
                     ) == 0i32
                 {
-                    let raw_mime = reconcat_mime(None, as_opt_str((*c).ct_subtype));
+                    let raw_mime = reconcat_mime(None, to_opt_string_lossy((*c).ct_subtype));
                     return (DC_MIMETYPE_AC_SETUP_FILE, Viewtype::File, Some(raw_mime));
                 }
 
                 let raw_mime = reconcat_mime(
-                    as_opt_str((*(*(*c).ct_type).tp_data.tp_discrete_type).dt_extension),
-                    as_opt_str((*c).ct_subtype),
+                    to_opt_string_lossy((*(*(*c).ct_type).tp_data.tp_discrete_type).dt_extension)
+                        .as_ref()
+                        .map(|x| x.as_str()),
+                    to_opt_string_lossy((*c).ct_subtype),
                 );
 
                 (DC_MIMETYPE_FILE, Viewtype::File, Some(raw_mime))
@@ -1038,9 +1056,9 @@ unsafe fn mailmime_get_mime_type(mime: *mut Mailmime) -> (libc::c_int, Viewtype,
             if (*(*(*c).ct_type).tp_data.tp_composite_type).ct_type
                 == MAILMIME_COMPOSITE_TYPE_MULTIPART as libc::c_int
             {
-                let subtype = as_opt_str((*c).ct_subtype);
+                let subtype = to_opt_string_lossy((*c).ct_subtype);
 
-                let mime_type = match subtype {
+                let mime_type = match subtype.as_ref().map(|x| x.as_str()) {
                     Some("alternative") => DC_MIMETYPE_MP_ALTERNATIVE,
                     Some("related") => DC_MIMETYPE_MP_RELATED,
                     Some("encrypted") => {
@@ -1075,9 +1093,9 @@ unsafe fn mailmime_get_mime_type(mime: *mut Mailmime) -> (libc::c_int, Viewtype,
     }
 }
 
-fn reconcat_mime(typ: Option<&str>, subtype: Option<&str>) -> String {
+fn reconcat_mime(typ: Option<&str>, subtype: Option<String>) -> String {
     let typ = typ.unwrap_or("application");
-    let subtype = subtype.unwrap_or("octet-stream");
+    let subtype = subtype.unwrap_or("octet-stream".to_string());
 
     format!("{}/{}", typ, subtype)
 }

src/dc_receive_imf.rs

@@ -65,12 +65,12 @@ pub unsafe fn dc_receive_imf(
 
     let mut mime_parser = MimeParser::new(context);
     if let Err(err) = mime_parser.parse(imf_raw) {
-        error!(context, "dc_receive_imf parse error: {}", err);
+        warn!(context, "dc_receive_imf parse error: {}", err);
     };
 
     if mime_parser.header.is_empty() {
         // Error - even adding an empty record won't help as we do not know the message ID
-        info!(context, "No header.");
+        warn!(context, "No header.");
         return;
     }
 
@@ -808,9 +808,9 @@ unsafe fn handle_reports(
                                     && !of_org_msgid.is_null()
                                     && !(*of_org_msgid).fld_value.is_null()
                                 {
-                                    if let Ok(rfc724_mid) = wrapmime::parse_message_id(as_str(
-                                        (*of_org_msgid).fld_value,
-                                    )) {
+                                    if let Ok(rfc724_mid) = wrapmime::parse_message_id(
+                                        &to_string_lossy((*of_org_msgid).fld_value),
+                                    ) {
                                         if let Some((chat_id, msg_id)) = message::mdn_from_ext(
                                             context,
                                             from_id,
@@ -993,7 +993,7 @@ unsafe fn create_or_lookup_group(
             let fld_message_id = (*field).fld_data.fld_message_id;
             if !fld_message_id.is_null() {
                 if let Some(extracted_grpid) =
-                    dc_extract_grpid_from_rfc724_mid(as_str((*fld_message_id).mid_value))
+                    dc_extract_grpid_from_rfc724_mid(&to_string_lossy((*fld_message_id).mid_value))
                 {
                     grpid = extracted_grpid.to_string();
                 } else {
@@ -1731,7 +1731,7 @@ fn is_known_rfc724_mid(context: &Context, rfc724_mid: *const libc::c_char) -> li
              LEFT JOIN chats c ON m.chat_id=c.id  \
              WHERE m.rfc724_mid=?  \
              AND m.chat_id>9 AND c.blocked=0;",
-            params![as_str(rfc724_mid)],
+            params![to_string_lossy(rfc724_mid)],
         )
         .unwrap_or_default() as libc::c_int
 }
@@ -1783,11 +1783,7 @@ unsafe fn is_msgrmsg_rfc724_mid_in_list(context: &Context, mid_list: *const clis
         while !cur.is_null() {
             if 0 != is_msgrmsg_rfc724_mid(
                 context,
-                if !cur.is_null() {
-                    as_str((*cur).data as *const libc::c_char)
-                } else {
-                    ""
-                },
+                &to_string_lossy((*cur).data as *const libc::c_char),
             ) {
                 return 1;
             }
@@ -1923,7 +1919,7 @@ unsafe fn add_or_lookup_contact_by_addr(
         .get_config(Config::ConfiguredAddr)
         .unwrap_or_default();
 
-    if addr_cmp(self_addr, as_str(addr_spec)) {
+    if addr_cmp(self_addr, to_string_lossy(addr_spec)) {
         *check_self = 1;
     }
 
@@ -1933,13 +1929,18 @@ unsafe fn add_or_lookup_contact_by_addr(
     /* add addr_spec if missing, update otherwise */
     let mut display_name_dec = "".to_string();
     if !display_name_enc.is_null() {
-        let tmp = dc_decode_header_words(as_str(display_name_enc));
+        let tmp = dc_decode_header_words(&to_string_lossy(display_name_enc));
         display_name_dec = normalize_name(&tmp);
     }
     /*can be NULL*/
-    let row_id = Contact::add_or_lookup(context, display_name_dec, as_str(addr_spec), origin)
-        .map(|(id, _)| id)
-        .unwrap_or_default();
+    let row_id = Contact::add_or_lookup(
+        context,
+        display_name_dec,
+        to_string_lossy(addr_spec),
+        origin,
+    )
+    .map(|(id, _)| id)
+    .unwrap_or_default();
     if 0 != row_id && !ids.contains(&row_id) {
         ids.push(row_id);
     };

src/dc_tools.rs

@@ -82,7 +82,7 @@ pub(crate) fn dc_str_from_clist(list: *const clist, delimiter: &str) -> String {
             if !res.is_empty() {
                 res += delimiter;
             }
-            res += as_str(rfc724_mid as *const libc::c_char);
+            res += &to_string_lossy(rfc724_mid as *const libc::c_char);
         }
     }
     res
@@ -303,9 +303,9 @@ pub(crate) fn dc_extract_grpid_from_rfc724_mid_list(list: *const clist) -> *mut
     if !list.is_null() {
         unsafe {
             for cur in (*list).into_iter() {
-                let mid = as_str(cur as *const libc::c_char);
+                let mid = to_string_lossy(cur as *const libc::c_char);
 
-                if let Some(grpid) = dc_extract_grpid_from_rfc724_mid(mid) {
+                if let Some(grpid) = dc_extract_grpid_from_rfc724_mid(&mid) {
                     return grpid.strdup();
                 }
             }
@@ -420,8 +420,8 @@ pub(crate) fn dc_delete_file(context: &Context, path: impl AsRef<std::path::Path
             context.call_cb(Event::DeletedBlobFile(dpath));
             true
         }
-        Err(_err) => {
-            warn!(context, "Cannot delete \"{}\".", dpath);
+        Err(err) => {
+            warn!(context, "Cannot delete \"{}\": {}", dpath, err);
             false
         }
     }
@@ -436,12 +436,13 @@ pub(crate) fn dc_copy_file(
     let dest_abs = dc_get_abs_path(context, &dest);
     match fs::copy(&src_abs, &dest_abs) {
         Ok(_) => true,
-        Err(_) => {
+        Err(err) => {
             error!(
                 context,
-                "Cannot copy \"{}\" to \"{}\".",
+                "Cannot copy \"{}\" to \"{}\": {}",
                 src.as_ref().display(),
                 dest.as_ref().display(),
+                err
             );
             false
         }
@@ -453,11 +454,12 @@ pub(crate) fn dc_create_folder(context: &Context, path: impl AsRef<std::path::Pa
     if !path_abs.exists() {
         match fs::create_dir_all(path_abs) {
             Ok(_) => true,
-            Err(_err) => {
+            Err(err) => {
                 warn!(
                     context,
-                    "Cannot create directory \"{}\".",
+                    "Cannot create directory \"{}\": {}",
                     path.as_ref().display(),
+                    err
                 );
                 false
             }
@@ -470,12 +472,13 @@ pub(crate) fn dc_create_folder(context: &Context, path: impl AsRef<std::path::Pa
 /// Write a the given content to provied file path.
 pub(crate) fn dc_write_file(context: &Context, path: impl AsRef<Path>, buf: &[u8]) -> bool {
     let path_abs = dc_get_abs_path(context, &path);
-    if let Err(_err) = fs::write(&path_abs, buf) {
+    if let Err(err) = fs::write(&path_abs, buf) {
         warn!(
             context,
-            "Cannot write {} bytes to \"{}\".",
+            "Cannot write {} bytes to \"{}\": {}",
             buf.len(),
             path.as_ref().display(),
+            err
         );
         false
     } else {
@@ -494,8 +497,9 @@ pub fn dc_read_file<P: AsRef<std::path::Path>>(
         Err(err) => {
             warn!(
                 context,
-                "Cannot read \"{}\" or file is empty.",
-                path.as_ref().display()
+                "Cannot read \"{}\" or file is empty: {}",
+                path.as_ref().display(),
+                err
             );
             Err(err.into())
         }
@@ -513,8 +517,9 @@ pub fn dc_open_file<P: AsRef<std::path::Path>>(
         Err(err) => {
             warn!(
                 context,
-                "Cannot read \"{}\" or file is empty.",
-                path.as_ref().display()
+                "Cannot read \"{}\" or file is empty: {}",
+                path.as_ref().display(),
+                err
             );
             Err(err.into())
         }
@@ -704,27 +709,6 @@ pub fn to_opt_string_lossy(s: *const libc::c_char) -> Option<String> {
     Some(to_string_lossy(s))
 }
 
-pub fn as_str<'a>(s: *const libc::c_char) -> &'a str {
-    as_str_safe(s).unwrap_or_else(|err| panic!("{}", err))
-}
-
-/// Converts a C string to either a Rust `&str` or `None` if  it is a null pointer.
-pub fn as_opt_str<'a>(s: *const libc::c_char) -> Option<&'a str> {
-    if s.is_null() {
-        return None;
-    }
-    Some(as_str(s))
-}
-
-fn as_str_safe<'a>(s: *const libc::c_char) -> Result<&'a str, Error> {
-    assert!(!s.is_null(), "cannot be used on null pointers");
-
-    let cstr = unsafe { CStr::from_ptr(s) };
-
-    cstr.to_str()
-        .map_err(|err| format_err!("Non utf8 string: '{:?}' ({:?})", cstr.to_bytes(), err))
-}
-
 /// Convert a C `*char` pointer to a [std::path::Path] slice.
 ///
 /// This converts a `*libc::c_char` pointer to a [Path] slice.  This
@@ -761,7 +745,11 @@ pub fn as_path<'a>(s: *const libc::c_char) -> &'a std::path::Path {
 #[allow(dead_code)]
 fn as_path_unicode<'a>(s: *const libc::c_char) -> &'a std::path::Path {
     assert!(!s.is_null(), "cannot be used on null pointers");
-    std::path::Path::new(as_str(s))
+
+    let cstr = unsafe { CStr::from_ptr(s) };
+    let str = cstr.to_str().unwrap_or_else(|err| panic!("{}", err));
+
+    std::path::Path::new(str)
 }
 
 pub(crate) fn time() -> i64 {

src/e2ee.rs

@@ -449,7 +449,7 @@ fn update_gossip_peerstates(
 
             let optional_field = unsafe { *optional_field };
             if !optional_field.fld_name.is_null()
-                && as_str(optional_field.fld_name) == "Autocrypt-Gossip"
+                && to_string_lossy(optional_field.fld_name) == "Autocrypt-Gossip"
             {
                 let value = to_string_lossy(optional_field.fld_value);
                 let gossip_header = Aheader::from_str(&value);
@@ -655,7 +655,7 @@ fn contains_report(mime: *mut Mailmime) -> bool {
 
         if tp_type == MAILMIME_TYPE_COMPOSITE_TYPE as libc::c_int
             && ct_type == MAILMIME_COMPOSITE_TYPE_MULTIPART as libc::c_int
-            && as_str(unsafe { (*mime.mm_content_type).ct_subtype }) == "report"
+            && to_string_lossy(unsafe { (*mime.mm_content_type).ct_subtype }) == "report"
         {
             return true;
         }

src/imex.rs

@@ -490,7 +490,7 @@ fn export_backup(context: &Context, dir: impl AsRef<Path>) -> Result<()> {
     context.sql.close(context);
     info!(
         context,
-        "Backup \"{}\" to \"{}\".",
+        "Backup '{}' to '{}'.",
         context.get_dbfile().display(),
         dest_path_filename.display(),
     );
@@ -499,8 +499,8 @@ fn export_backup(context: &Context, dir: impl AsRef<Path>) -> Result<()> {
     if !copied {
         let s = dest_path_filename.to_string_lossy().to_string();
         bail!(
-            "could not copy file from {:?} to {:?}",
-            context.get_dbfile(),
+            "could not copy file from '{}' to '{}'",
+            context.get_dbfile().display(),
             s
         );
     }

src/wrapmime.rs

@@ -143,7 +143,8 @@ pub fn get_field_date(imffields: *mut mailimf_fields) -> Result<i64, Error> {
 
 fn mailimf_get_recipients_add_addr(recipients: &mut HashSet<String>, mb: *mut mailimf_mailbox) {
     if !mb.is_null() {
-        let addr_norm = addr_normalize(as_str(unsafe { (*mb).mb_addr_spec }));
+        let addr = to_string_lossy(unsafe { (*mb).mb_addr_spec });
+        let addr_norm = addr_normalize(&addr);
         recipients.insert(addr_norm.into());
     }
 }
@@ -382,8 +383,8 @@ pub fn mailimf_find_first_addr(mb_list: *const mailimf_mailbox_list) -> Option<S
     for cur in unsafe { (*(*mb_list).mb_list).into_iter() } {
         let mb = cur as *mut mailimf_mailbox;
         if !mb.is_null() && !unsafe { (*mb).mb_addr_spec.is_null() } {
-            let addr = unsafe { as_str((*mb).mb_addr_spec) };
-            return Some(addr_normalize(addr).to_string());
+            let addr = unsafe { to_string_lossy((*mb).mb_addr_spec) };
+            return Some(addr_normalize(&addr).to_string());
         }
     }
 
@@ -489,7 +490,9 @@ pub fn content_type_needs_encoding(content: *const mailmime_content) -> bool {
         if (*(*content).ct_type).tp_type == MAILMIME_TYPE_COMPOSITE_TYPE as libc::c_int {
             let composite = (*(*content).ct_type).tp_data.tp_composite_type;
             match (*composite).ct_type as u32 {
-                MAILMIME_COMPOSITE_TYPE_MESSAGE => as_str((*content).ct_subtype) != "rfc822",
+                MAILMIME_COMPOSITE_TYPE_MESSAGE => {
+                    to_string_lossy((*content).ct_subtype) != "rfc822"
+                }
                 MAILMIME_COMPOSITE_TYPE_MULTIPART => false,
                 _ => false,
             }