bump version to 1.28

fix imap delimiter

CHANGELOG.md

@@ -1,5 +1,19 @@
 # Changelog 
 
+## 1.28.0
+
+- new flag DC_GCL_FOR_FORWARDING for dc_get_chatlist()
+  that will sort the "saved messages" chat to the top of the chatlist #1336
+- mark mails as being deleted from server in dc_empty_server() #1333
+- fix interaction with servers that do not allow folder creation on root-level;
+  use path separator as defined by the email server #1359
+- fix group creation if group was created by non-delta clients #1357
+- fix showing replies from non-delta clients #1353
+- fix member list on rejoining left groups #1343
+- fix crash when using empty groups #1354
+- fix potential crash on special names #1350
+
+
 ## 1.27.0
 
 - handle keys reliably on armv7 #1327

Cargo.lock

@@ -624,7 +624,7 @@ dependencies = [
 
 [[package]]
 name = "deltachat"
-version = "1.27.0"
+version = "1.28.0"
 dependencies = [
  "async-imap 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "async-native-tls 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -690,9 +690,9 @@ dependencies = [
 
 [[package]]
 name = "deltachat_ffi"
-version = "1.27.0"
+version = "1.28.0"
 dependencies = [
- "deltachat 1.27.0",
+ "deltachat 1.28.0",
  "failure 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "human-panic 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.67 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "deltachat"
-version = "1.27.0"
+version = "1.28.0"
 authors = ["Delta Chat Developers (ML) <delta@codespeak.net>"]
 edition = "2018"
 license = "MPL-2.0"

ci_scripts/old/run-python.sh

@@ -46,6 +46,7 @@ if [ -n "$TESTS" ]; then
     tox --workdir "$TOXWORKDIR" -e py37 -- --reruns 3 -k "not qr"
     tox --workdir "$TOXWORKDIR" -e py37 -- --reruns 3 -k "qr"
     unset DCC_PY_LIVECONFIG
+    unset DCC_NEW_TMP_EMAIL
     tox --workdir "$TOXWORKDIR" -p4 -e lint,py35,py36,doc
     tox --workdir "$TOXWORKDIR" -e auditwheels
     popd

ci_scripts/remote_python_packaging.sh

@@ -32,11 +32,11 @@ ssh $SSHTARGET bash -c "cat >$BUILDDIR/exec_docker_run" <<_HERE
     set +x -e
     cd $BUILDDIR
     export DCC_PY_LIVECONFIG=$DCC_PY_LIVECONFIG
-
+    export DCC_NEW_TMP_EMAIL=$DCC_NEW_TMP_EMAIL
     set -x
 
     # run everything else inside docker 
-    docker run -e DCC_PY_LIVECONFIG \
+    docker run -e DCC_NEW_TMP_EMAIL -e DCC_PY_LIVECONFIG \
        --rm -it -v \$(pwd):/mnt -w /mnt \
        deltachat/coredeps ci_scripts/run_all.sh
 

ci_scripts/remote_tests_python.sh

@@ -30,6 +30,7 @@ ssh $SSHTARGET <<_HERE
     export CARGO_TARGET_DIR=\`pwd\`/../target
     export TARGET=release
     export DCC_PY_LIVECONFIG=$DCC_PY_LIVECONFIG
+    export DCC_NEW_TMP_EMAIL=$DCC_NEW_TMP_EMAIL
 
     #we rely on tox/virtualenv being available in the host
     #rm -rf virtualenv venv

ci_scripts/run_all.sh

@@ -37,7 +37,8 @@ mkdir -p $TOXWORKDIR
 # XXX we may switch on some live-tests on for better ensurances 
 # Note that the independent remote_tests_python step does all kinds of
 # live-testing already. 
-unset DCC_PY_LIVECONFIG 
+unset DCC_PY_LIVECONFIG
+unset DCC_NEW_TMP_EMAIL
 tox --workdir "$TOXWORKDIR" -e py35,py36,py37,py38,auditwheels
 popd
 

deltachat-ffi/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "deltachat_ffi"
-version = "1.27.0"
+version = "1.28.0"
 description = "Deltachat FFI"
 authors = ["Delta Chat Developers (ML) <delta@codespeak.net>"]
 edition = "2018"

deltachat-ffi/deltachat.h

@@ -901,6 +901,7 @@ int             dc_preconfigure_keypair        (dc_context_t* context, const cha
 #define         DC_GCL_ARCHIVED_ONLY         0x01
 #define         DC_GCL_NO_SPECIALS           0x02
 #define         DC_GCL_ADD_ALLDONE_HINT      0x04
+#define         DC_GCL_FOR_FORWARDING        0x08
 
 
 /**
@@ -939,6 +940,8 @@ int             dc_preconfigure_keypair        (dc_context_t* context, const cha
  *       if DC_GCL_ARCHIVED_ONLY is not set, only unarchived chats are returned and
  *       the pseudo-chat DC_CHAT_ID_ARCHIVED_LINK is added if there are _any_ archived
  *       chats
+ *     - the flag DC_GCL_FOR_FORWARDING sorts "Saved messages" to the top of the chatlist,
+ *       typically used on forwarding, may be combined with DC_GCL_NO_SPECIALS
  *     - if the flag DC_GCL_NO_SPECIALS is set, deaddrop and archive link are not added
  *       to the list (may be used eg. for selecting chats on forwarding, the flag is
  *       not needed when DC_GCL_ARCHIVED_ONLY is already set)

python/tests/test_account.py

@@ -76,6 +76,20 @@ class TestOfflineAccountBasic:
         with pytest.raises(KeyError):
             ac1.get_config("123123")
 
+    def test_empty_group_bcc_self_enabled(self, acfactory):
+        ac1 = acfactory.get_configured_offline_account()
+        ac1.set_config("bcc_self", "1")
+        chat = ac1.create_group_chat(name="group1")
+        msg = chat.send_text("msg1")
+        assert msg in chat.get_messages()
+
+    def test_empty_group_bcc_self_disabled(self, acfactory):
+        ac1 = acfactory.get_configured_offline_account()
+        ac1.set_config("bcc_self", "0")
+        chat = ac1.create_group_chat(name="group1")
+        msg = chat.send_text("msg1")
+        assert msg in chat.get_messages()
+
 
 class TestOfflineContact:
     def test_contact_attr(self, acfactory):
@@ -1366,6 +1380,80 @@ class TestGroupStressTests:
         # Message should be encrypted because keys of other members are gossiped
         assert msg.is_encrypted()
 
+    def test_synchronize_member_list_on_group_rejoin(self, acfactory, lp):
+        """
+        Test that user recreates group member list when it joins the group again.
+
+        ac1 creates a group with two other accounts: ac2 and ac3
+        Then it removes ac2, removes ac3 and adds ac2 back.
+        ac2 did not see that ac3 is removed, so it should rebuild member list from scratch.
+        """
+        lp.sec("creating and configuring five accounts")
+        accounts = [acfactory.get_online_configuring_account() for i in range(3)]
+        for acc in accounts:
+            wait_configuration_progress(acc, 1000)
+        ac1 = accounts.pop()
+
+        lp.sec("ac1: setting up contacts with 2 other members")
+        contacts = []
+        for acc, name in zip(accounts, ["ac2", "ac3"]):
+            contact = ac1.create_contact(acc.get_config("addr"), name=name)
+            contacts.append(contact)
+
+            # make sure we accept the "hi" message
+            ac1.create_chat_by_contact(contact)
+
+            # make sure the other side accepts our messages
+            c1 = acc.create_contact(ac1.get_config("addr"), "a member")
+            chat1 = acc.create_chat_by_contact(c1)
+
+            # send a message to get the contact key via autocrypt header
+            chat1.send_text("hi")
+            msg = ac1.wait_next_incoming_message()
+            assert msg.text == "hi"
+
+        ac2, ac3 = accounts
+
+        lp.sec("ac1: creating group chat with 2 other members")
+        chat = ac1.create_group_chat("title1")
+        for contact in contacts:
+            chat.add_contact(contact)
+        assert not chat.is_promoted()
+
+        lp.sec("ac1: send mesage to new group chat")
+        msg = chat.send_text("hello")
+        assert chat.is_promoted()
+        assert msg.is_encrypted()
+
+        num_contacts = len(chat.get_contacts())
+        assert num_contacts == 3
+
+        lp.sec("checking that the chat arrived correctly")
+        for ac in accounts:
+            msg = ac.wait_next_incoming_message()
+            assert msg.text == "hello"
+            print("chat is", msg.chat)
+            assert len(msg.chat.get_contacts()) == 3
+
+        lp.sec("ac1: removing ac2")
+        chat.remove_contact(contacts[0])
+
+        lp.sec("ac2: wait for a message about removal from the chat")
+        msg = ac2.wait_next_incoming_message()
+
+        lp.sec("ac1: removing ac3")
+        chat.remove_contact(contacts[1])
+
+        lp.sec("ac1: adding ac2 back")
+        # Group is promoted, message is sent automatically
+        assert chat.is_promoted()
+        chat.add_contact(contacts[0])
+
+        lp.sec("ac2: check that ac3 is removed")
+        msg = ac2.wait_next_incoming_message()
+
+        assert len(msg.chat.get_contacts()) == len(chat.get_contacts())
+
 
 class TestOnlineConfigureFails:
     def test_invalid_password(self, acfactory):

python/tox.ini

@@ -14,6 +14,7 @@ passenv =
     DCC_RS_DEV
     DCC_RS_TARGET
     DCC_PY_LIVECONFIG
+    DCC_NEW_TMP_EMAIL
     CARGO_TARGET_DIR
     RUSTC_WRAPPER
 deps = 

src/chatlist.rs

@@ -1,5 +1,6 @@
 //! # Chat list module
 
+use crate::chat;
 use crate::chat::*;
 use crate::constants::*;
 use crate::contact::*;
@@ -73,6 +74,8 @@ impl Chatlist {
     ///   if DC_GCL_ARCHIVED_ONLY is not set, only unarchived chats are returned and
     ///   the pseudo-chat DC_CHAT_ID_ARCHIVED_LINK is added if there are *any* archived
     ///   chats
+    /// - the flag DC_GCL_FOR_FORWARDING sorts "Saved messages" to the top of the chatlist,
+    //    typically used on forwarding, may be combined with DC_GCL_NO_SPECIALS
     /// - if the flag DC_GCL_NO_SPECIALS is set, deaddrop and archive link are not added
     ///   to the list (may be used eg. for selecting chats on forwarding, the flag is
     ///   not needed when DC_GCL_ARCHIVED_ONLY is already set)
@@ -190,6 +193,13 @@ impl Chatlist {
             )?
         } else {
             //  show normal chatlist
+            let sort_id_up = if 0 != listflags & DC_GCL_FOR_FORWARDING {
+                chat::lookup_by_contact_id(context, DC_CONTACT_ID_SELF)
+                    .unwrap_or_default()
+                    .0
+            } else {
+                ChatId::new(0)
+            };
             let mut ids = context.sql.query_map(
                 "SELECT c.id, m.id
                  FROM chats c
@@ -204,17 +214,19 @@ impl Chatlist {
                    AND c.blocked=0
                    AND NOT c.archived=?2
                  GROUP BY c.id
-                 ORDER BY c.archived=?3 DESC, IFNULL(m.timestamp,c.created_timestamp) DESC, m.id DESC;",
-                params![MessageState::OutDraft, ChatVisibility::Archived, ChatVisibility::Pinned],
+                 ORDER BY c.id=?3 DESC, c.archived=?4 DESC, IFNULL(m.timestamp,c.created_timestamp) DESC, m.id DESC;",
+                params![MessageState::OutDraft, ChatVisibility::Archived, sort_id_up, ChatVisibility::Pinned],
                 process_row,
                 process_rows,
             )?;
             if 0 == listflags & DC_GCL_NO_SPECIALS {
                 if let Some(last_deaddrop_fresh_msg_id) = get_last_deaddrop_fresh_msg(context) {
-                    ids.insert(
-                        0,
-                        (ChatId::new(DC_CHAT_ID_DEADDROP), last_deaddrop_fresh_msg_id),
-                    );
+                    if 0 == listflags & DC_GCL_FOR_FORWARDING {
+                        ids.insert(
+                            0,
+                            (ChatId::new(DC_CHAT_ID_DEADDROP), last_deaddrop_fresh_msg_id),
+                        );
+                    }
                 }
                 add_archived_link_item = true;
             }
@@ -399,6 +411,22 @@ mod tests {
         assert_eq!(chats.len(), 1);
     }
 
+    #[test]
+    fn test_sort_self_talk_up_on_forward() {
+        let t = dummy_context();
+        t.ctx.update_device_chats().unwrap();
+
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert!(Chat::load_from_db(&t.ctx, chats.get_chat_id(0))
+            .unwrap()
+            .is_device_talk());
+
+        let chats = Chatlist::try_load(&t.ctx, DC_GCL_FOR_FORWARDING, None, None).unwrap();
+        assert!(Chat::load_from_db(&t.ctx, chats.get_chat_id(0))
+            .unwrap()
+            .is_self_talk());
+    }
+
     #[test]
     fn test_search_special_chat_names() {
         let t = dummy_context();

src/configure/mod.rs

@@ -371,7 +371,7 @@ pub(crate) fn JobConfigureImap(context: &Context) -> job::Status {
                 let create_mvbox = context.get_config_bool(Config::MvboxWatch)
                     || context.get_config_bool(Config::MvboxMove);
                 let imap = &context.inbox_thread.read().unwrap().imap;
-                if let Err(err) = imap.ensure_configured_folders(context, create_mvbox) {
+                if let Err(err) = imap.configure_folders(context, create_mvbox) {
                     warn!(context, "configuring folders failed: {:?}", err);
                     false
                 } else {

src/constants.rs

@@ -80,6 +80,7 @@ pub(crate) const DC_FROM_HANDSHAKE: i32 = 0x01;
 pub const DC_GCL_ARCHIVED_ONLY: usize = 0x01;
 pub const DC_GCL_NO_SPECIALS: usize = 0x02;
 pub const DC_GCL_ADD_ALLDONE_HINT: usize = 0x04;
+pub const DC_GCL_FOR_FORWARDING: usize = 0x08;
 
 pub const DC_GCM_ADDDAYMARKER: u32 = 0x01;
 
@@ -213,6 +214,9 @@ pub const DC_BOB_SUCCESS: i32 = 1;
 // max. width/height of an avatar
 pub const AVATAR_SIZE: u32 = 192;
 
+// this value can be increased if the folder configuration is changed and must be redone on next program start
+pub const DC_FOLDERS_CONFIGURED_VERSION: i32 = 3;
+
 #[derive(
     Debug,
     Display,

src/contact.rs

@@ -1067,7 +1067,7 @@ pub fn normalize_name(full_name: impl AsRef<str>) -> String {
     }
 
     let len = full_name.len();
-    if len > 0 {
+    if len > 1 {
         let firstchar = full_name.as_bytes()[0];
         let lastchar = full_name.as_bytes()[len - 1];
         if firstchar == b'\'' && lastchar == b'\''
@@ -1176,6 +1176,10 @@ mod tests {
     fn test_normalize_name() {
         assert_eq!(&normalize_name("Doe, John"), "John Doe");
         assert_eq!(&normalize_name(" hello world   "), "hello world");
+        assert_eq!(&normalize_name("<"), "<");
+        assert_eq!(&normalize_name(">"), ">");
+        assert_eq!(&normalize_name("'"), "'");
+        assert_eq!(&normalize_name("\""), "\"");
     }
 
     #[test]

src/dc_receive_imf.rs

@@ -389,7 +389,11 @@ fn add_parts(
             let (new_chat_id, new_chat_id_blocked) = create_or_lookup_group(
                 context,
                 &mut mime_parser,
-                allow_creation,
+                if test_normal_chat_id.is_unset() {
+                    allow_creation
+                } else {
+                    true
+                },
                 create_blocked,
                 from_id,
                 to_ids,
@@ -1023,6 +1027,17 @@ fn create_or_lookup_group(
     // add members to group/check members
     if recreate_member_list {
         if !chat::is_contact_in_chat(context, chat_id, DC_CONTACT_ID_SELF) {
+            // Members could have been removed while we were
+            // absent. We can't use existing member list and need to
+            // start from scratch.
+            sql::execute(
+                context,
+                &context.sql,
+                "DELETE FROM chats_contacts WHERE chat_id=?;",
+                params![chat_id],
+            )
+            .ok();
+
             chat::add_to_chat_contacts_table(context, chat_id, DC_CONTACT_ID_SELF);
         }
         if from_id > DC_CONTACT_ID_LAST_SPECIAL
@@ -1477,6 +1492,7 @@ fn is_known_rfc724_mid_in_list(context: &Context, mid_list: &str) -> bool {
 
 /// Check if a message is a reply to a known message (messenger or non-messenger).
 fn is_known_rfc724_mid(context: &Context, rfc724_mid: &str) -> bool {
+    let rfc724_mid = rfc724_mid.trim_start_matches('<').trim_end_matches('>');
     context
         .sql
         .exists(
@@ -1523,6 +1539,7 @@ pub(crate) fn is_msgrmsg_rfc724_mid_in_list(context: &Context, mid_list: &str) -
 
 /// Check if a message is a reply to any messenger message.
 fn is_msgrmsg_rfc724_mid(context: &Context, rfc724_mid: &str) -> bool {
+    let rfc724_mid = rfc724_mid.trim_start_matches('<').trim_end_matches('>');
     context
         .sql
         .exists(
@@ -1612,7 +1629,9 @@ fn dc_create_incoming_rfc724_mid(
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::test_utils::dummy_context;
+    use crate::chatlist::Chatlist;
+    use crate::message::Message;
+    use crate::test_utils::{dummy_context, TestContext};
 
     #[test]
     fn test_hex_hash() {
@@ -1671,4 +1690,170 @@ mod tests {
             Some("123-45-9@stub".into())
         );
     }
+
+    #[test]
+    fn test_is_known_rfc724_mid() {
+        let t = dummy_context();
+        let mut msg = Message::new(Viewtype::Text);
+        msg.text = Some("first message".to_string());
+        let msg_id = chat::add_device_msg(&t.ctx, None, Some(&mut msg)).unwrap();
+        let msg = Message::load_from_db(&t.ctx, msg_id).unwrap();
+
+        // Message-IDs may or may not be surrounded by angle brackets
+        assert!(is_known_rfc724_mid(
+            &t.ctx,
+            format!("<{}>", msg.rfc724_mid).as_str()
+        ));
+        assert!(is_known_rfc724_mid(&t.ctx, &msg.rfc724_mid));
+        assert!(!is_known_rfc724_mid(&t.ctx, "nonexistant@message.id"));
+    }
+
+    #[test]
+    fn test_is_msgrmsg_rfc724_mid() {
+        let t = dummy_context();
+        let mut msg = Message::new(Viewtype::Text);
+        msg.text = Some("first message".to_string());
+        let msg_id = chat::add_device_msg(&t.ctx, None, Some(&mut msg)).unwrap();
+        let msg = Message::load_from_db(&t.ctx, msg_id).unwrap();
+
+        // Message-IDs may or may not be surrounded by angle brackets
+        assert!(is_msgrmsg_rfc724_mid(
+            &t.ctx,
+            format!("<{}>", msg.rfc724_mid).as_str()
+        ));
+        assert!(is_msgrmsg_rfc724_mid(&t.ctx, &msg.rfc724_mid));
+        assert!(!is_msgrmsg_rfc724_mid(&t.ctx, "nonexistant@message.id"));
+    }
+
+    fn configured_offline_context() -> TestContext {
+        let t = dummy_context();
+        t.ctx
+            .set_config(Config::Addr, Some("alice@example.org"))
+            .unwrap();
+        t.ctx
+            .set_config(Config::ConfiguredAddr, Some("alice@example.org"))
+            .unwrap();
+        t.ctx.set_config(Config::Configured, Some("1")).unwrap();
+        t
+    }
+
+    static MSGRMSG: &[u8] = b"From: Bob <bob@example.org>\n\
+                    To: alice@example.org\n\
+                    Chat-Version: 1.0\n\
+                    Subject: Chat: hello\n\
+                    Message-ID: <Mr.1111@example.org>\n\
+                    Date: Sun, 22 Mar 2020 22:37:55 +0000\n\
+                    \n\
+                    hello\n";
+
+    static ONETOONE_NOREPLY_MAIL: &[u8] = b"From: Bob <bob@example.org>\n\
+                    To: alice@example.org\n\
+                    Subject: Chat: hello\n\
+                    Message-ID: <2222@example.org>\n\
+                    Date: Sun, 22 Mar 2020 22:37:56 +0000\n\
+                    \n\
+                    hello\n";
+
+    static GRP_MAIL: &[u8] = b"From: bob@example.org\n\
+                    To: alice@example.org, claire@example.org\n\
+                    Subject: group with Alice, Bob and Claire\n\
+                    Message-ID: <3333@example.org>\n\
+                    Date: Sun, 22 Mar 2020 22:37:57 +0000\n\
+                    \n\
+                    hello\n";
+
+    #[test]
+    fn test_adhoc_group_show_chats_only() {
+        let t = configured_offline_context();
+        assert_eq!(t.ctx.get_config_int(Config::ShowEmails), 0);
+
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert_eq!(chats.len(), 0);
+
+        dc_receive_imf(&t.ctx, MSGRMSG, "INBOX", 1, false).unwrap();
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert_eq!(chats.len(), 1);
+
+        dc_receive_imf(&t.ctx, ONETOONE_NOREPLY_MAIL, "INBOX", 1, false).unwrap();
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert_eq!(chats.len(), 1);
+
+        dc_receive_imf(&t.ctx, GRP_MAIL, "INBOX", 1, false).unwrap();
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert_eq!(chats.len(), 1);
+    }
+
+    #[test]
+    fn test_adhoc_group_show_accepted_contact_unknown() {
+        let t = configured_offline_context();
+        t.ctx.set_config(Config::ShowEmails, Some("1")).unwrap();
+        dc_receive_imf(&t.ctx, GRP_MAIL, "INBOX", 1, false).unwrap();
+
+        // adhoc-group with unknown contacts with show_emails=accepted is ignored for unknown contacts
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert_eq!(chats.len(), 0);
+    }
+
+    #[test]
+    fn test_adhoc_group_show_accepted_contact_known() {
+        let t = configured_offline_context();
+        t.ctx.set_config(Config::ShowEmails, Some("1")).unwrap();
+        Contact::create(&t.ctx, "Bob", "bob@example.org").unwrap();
+        dc_receive_imf(&t.ctx, GRP_MAIL, "INBOX", 1, false).unwrap();
+
+        // adhoc-group with known contacts with show_emails=accepted is still ignored for known contacts
+        // (and existent chat is required)
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert_eq!(chats.len(), 0);
+    }
+
+    #[test]
+    fn test_adhoc_group_show_accepted_contact_accepted() {
+        let t = configured_offline_context();
+        t.ctx.set_config(Config::ShowEmails, Some("1")).unwrap();
+
+        // accept Bob by accepting a delta-message from Bob
+        dc_receive_imf(&t.ctx, MSGRMSG, "INBOX", 1, false).unwrap();
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert_eq!(chats.len(), 1);
+        assert!(chats.get_chat_id(0).is_deaddrop());
+        let chat_id = chat::create_by_msg_id(&t.ctx, chats.get_msg_id(0).unwrap()).unwrap();
+        assert!(!chat_id.is_special());
+        let chat = chat::Chat::load_from_db(&t.ctx, chat_id).unwrap();
+        assert_eq!(chat.typ, Chattype::Single);
+        assert_eq!(chat.name, "Bob");
+        assert_eq!(chat::get_chat_contacts(&t.ctx, chat_id).len(), 1);
+        assert_eq!(chat::get_chat_msgs(&t.ctx, chat_id, 0, None).len(), 1);
+
+        // receive a non-delta-message from Bob, shows up because of the show_emails setting
+        dc_receive_imf(&t.ctx, ONETOONE_NOREPLY_MAIL, "INBOX", 2, false).unwrap();
+        assert_eq!(chat::get_chat_msgs(&t.ctx, chat_id, 0, None).len(), 2);
+
+        // let Bob create an adhoc-group by a non-delta-message, shows up because of the show_emails setting
+        dc_receive_imf(&t.ctx, GRP_MAIL, "INBOX", 3, false).unwrap();
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert_eq!(chats.len(), 2);
+        let chat_id = chat::create_by_msg_id(&t.ctx, chats.get_msg_id(0).unwrap()).unwrap();
+        let chat = chat::Chat::load_from_db(&t.ctx, chat_id).unwrap();
+        assert_eq!(chat.typ, Chattype::Group);
+        assert_eq!(chat.name, "group with Alice, Bob and Claire");
+        assert_eq!(chat::get_chat_contacts(&t.ctx, chat_id).len(), 3);
+    }
+
+    #[test]
+    fn test_adhoc_group_show_all() {
+        let t = configured_offline_context();
+        t.ctx.set_config(Config::ShowEmails, Some("2")).unwrap();
+        dc_receive_imf(&t.ctx, GRP_MAIL, "INBOX", 1, false).unwrap();
+
+        // adhoc-group with unknown contacts with show_emails=all will show up in the deaddrop
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert_eq!(chats.len(), 1);
+        assert!(chats.get_chat_id(0).is_deaddrop());
+        let chat_id = chat::create_by_msg_id(&t.ctx, chats.get_msg_id(0).unwrap()).unwrap();
+        let chat = chat::Chat::load_from_db(&t.ctx, chat_id).unwrap();
+        assert_eq!(chat.typ, Chattype::Group);
+        assert_eq!(chat.name, "group with Alice, Bob and Claire");
+        assert_eq!(chat::get_chat_contacts(&t.ctx, chat_id).len(), 3);
+    }
 }

src/imap/mod.rs

@@ -188,7 +188,6 @@ struct ImapConfig {
     /// True if the server has MOVE capability as defined in
     /// https://tools.ietf.org/html/rfc6851
     pub can_move: bool,
-    pub imap_delimiter: char,
 }
 
 impl Default for ImapConfig {
@@ -206,7 +205,6 @@ impl Default for ImapConfig {
             selected_folder_needs_expunge: false,
             can_idle: false,
             can_move: false,
-            imap_delimiter: '.',
         }
     }
 }
@@ -1074,12 +1072,14 @@ impl Imap {
         let folders_configured = context
             .sql
             .get_raw_config_int(context, "folders_configured");
-        if folders_configured.unwrap_or_default() >= 3 {
-            // the "3" here we increase if we have future updates to
-            // to folder configuration
+        if folders_configured.unwrap_or_default() >= DC_FOLDERS_CONFIGURED_VERSION {
             return Ok(());
         }
 
+        self.configure_folders(context, create_mvbox)
+    }
+
+    pub fn configure_folders(&self, context: &Context, create_mvbox: bool) -> Result<()> {
         task::block_on(async move {
             if !self.is_connected().await {
                 return Err(Error::NoConnection);
@@ -1104,7 +1104,15 @@ impl Imap {
                         });
                 info!(context, "sentbox folder is {:?}", sentbox_folder);
 
-                let delimiter = self.config.read().await.imap_delimiter;
+                let mut delimiter = ".";
+                if let Some(folder) = folders.first() {
+                    if let Some(d) = folder.delimiter() {
+                        if !d.is_empty() {
+                            delimiter = d;
+                        }
+                    }
+                }
+                info!(context, "Using \"{}\" as folder-delimiter.", delimiter);
                 let fallback_folder = format!("INBOX{}DeltaChat", delimiter);
 
                 let mut mvbox_folder = folders
@@ -1168,9 +1176,11 @@ impl Imap {
                         Some(sentbox_folder.name()),
                     )?;
                 }
-                context
-                    .sql
-                    .set_raw_config_int(context, "folders_configured", 3)?;
+                context.sql.set_raw_config_int(
+                    context,
+                    "folders_configured",
+                    DC_FOLDERS_CONFIGURED_VERSION,
+                )?;
             }
             info!(context, "FINISHED configuring IMAP-folders.");
             Ok(())
@@ -1234,6 +1244,18 @@ impl Imap {
                     error!(context, "expunge failed {}: {:?}", folder, err);
                 }
             }
+
+            if let Err(err) = crate::sql::execute(
+                context,
+                &context.sql,
+                "UPDATE msgs SET server_folder='',server_uid=0 WHERE server_folder=?",
+                params![folder],
+            ) {
+                warn!(
+                    context,
+                    "Failed to reset server_uid and server_folder for deleted messages: {}", err
+                );
+            }
         });
     }
 }

src/mimefactory.rs

@@ -368,7 +368,7 @@ impl<'a, 'b> MimeFactory<'a, 'b> {
             self.from_addr.clone(),
         );
 
-        let mut to = Vec::with_capacity(self.recipients.len());
+        let mut to = Vec::new();
         for (name, addr) in self.recipients.iter() {
             if name.is_empty() {
                 to.push(Address::new_mailbox(addr.clone()));
@@ -380,6 +380,10 @@ impl<'a, 'b> MimeFactory<'a, 'b> {
             }
         }
 
+        if to.is_empty() {
+            to.push(from.clone());
+        }
+
         if !self.references.is_empty() {
             unprotected_headers.push(Header::new("References".into(), self.references.clone()));
         }