Rewrite IMAP expunge

k9mail-library/src/main/java/com/fsck/k9/mail/Folder.java

@@ -116,6 +116,9 @@ public abstract void setFlags(List<? extends Message> messages, Set<Flag> flags,
     public void expunge() throws MessagingException
         {}
 
+    public void expungeUids(List<String> uids) throws MessagingException {
+    }
+
     /**
      * Populate a list of messages based upon a FetchProfile.  See {@link FetchProfile} for the things that can
      * be fetched.

k9mail-library/src/main/java/com/fsck/k9/mail/store/imap/Capabilities.java

@@ -14,4 +14,5 @@ class Capabilities {
     public static final String COMPRESS_DEFLATE = "COMPRESS=DEFLATE";
     public static final String STARTTLS = "STARTTLS";
     public static final String SPECIAL_USE = "SPECIAL-USE";
+    public static final String UID_PLUS = "UIDPLUS";
 }

k9mail-library/src/main/java/com/fsck/k9/mail/store/imap/Commands.java

@@ -18,4 +18,5 @@ class Commands {
     public static final String UID_STORE = "UID STORE";
     public static final String UID_FETCH = "UID FETCH";
     public static final String UID_COPY = "UID COPY";
+    public static final String UID_EXPUNGE = "UID EXPUNGE";
 }

k9mail-library/src/main/java/com/fsck/k9/mail/store/imap/ImapConnection.java

@@ -710,6 +710,10 @@ protected boolean isIdleCapable() {
         return capabilities.contains(Capabilities.IDLE);
     }
 
+    boolean isUidPlusCapable() {
+        return capabilities.contains(Capabilities.UID_PLUS);
+    }
+
     public void close() {
         open = false;
         stacktraceForClose = new Exception();

k9mail-library/src/main/java/com/fsck/k9/mail/store/imap/ImapFolder.java

@@ -1259,6 +1259,30 @@ public void expunge() throws MessagingException {
         }
     }
 
+    @Override
+    public void expungeUids(List<String> uids) throws MessagingException {
+        if (uids == null || uids.isEmpty()) {
+            throw new IllegalArgumentException("expungeUids() must be called with a non-empty set of UIDs");
+        }
+
+        open(OPEN_MODE_RW);
+        checkOpen();
+
+        try {
+            if (connection.isUidPlusCapable()) {
+                Set<Long> longUids = new HashSet<>(uids.size());
+                for (String uid : uids) {
+                    longUids.add(Long.parseLong(uid));
+                }
+                connection.executeCommandWithIdSet(Commands.UID_EXPUNGE, "", longUids);
+            } else {
+                executeSimpleCommand("EXPUNGE");
+            }
+        } catch (IOException ioe) {
+            throw ioExceptionHandler(connection, ioe);
+        }
+    }
+
     @Override
     public void setFlags(Set<Flag> flags, boolean value) throws MessagingException {
         open(OPEN_MODE_RW);

k9mail-library/src/test/java/com/fsck/k9/mail/store/imap/ImapFolderTest.java

@@ -1005,6 +1005,28 @@ public void expunge_shouldIssueExpungeCommand() throws Exception {
         verify(imapConnection).executeSimpleCommand("EXPUNGE");
     }
 
+    @Test
+    public void expungeUids_withUidPlus_shouldIssueUidExpungeCommand() throws Exception {
+        ImapFolder folder = createFolder("Folder");
+        prepareImapFolderForOpen(OPEN_MODE_RW);
+        when(imapConnection.isUidPlusCapable()).thenReturn(true);
+
+        folder.expungeUids(singletonList("1"));
+
+        assertCommandWithIdsIssued("UID EXPUNGE 1");
+    }
+
+    @Test
+    public void expungeUids_withoutUidPlus_shouldIssueExpungeCommand() throws Exception {
+        ImapFolder folder = createFolder("Folder");
+        prepareImapFolderForOpen(OPEN_MODE_RW);
+        when(imapConnection.isUidPlusCapable()).thenReturn(false);
+
+        folder.expungeUids(singletonList("1"));
+
+        verify(imapConnection).executeSimpleCommand("EXPUNGE");
+    }
+
     @Test
     public void setFlags_shouldIssueUidStoreCommand() throws Exception {
         ImapFolder folder = createFolder("Folder");
@@ -1226,8 +1248,8 @@ private void assertCommandWithIdsIssued(String expectedCommand) throws Messaging
 
         for (int i = 0, end = commandPrefixes.size(); i < end; i++) {
             String command = commandPrefixes.get(i) +
-                    " " + ImapUtility.join(",", commandUids.get(i)) + " " +
-                    commandSuffixes.get(i);
+                    " " + ImapUtility.join(",", commandUids.get(i)) +
+                    ((commandSuffixes.get(i).length() == 0) ? "" : " " + commandSuffixes.get(i));
             if (command.equals(expectedCommand)) {
                 return;
             }

k9mail/src/main/java/com/fsck/k9/controller/MessagingController.java

@@ -1830,7 +1830,7 @@ void processPendingAppend(PendingAppend command, Account account) throws Messagi
                     if (remoteDate != null) {
                         remoteMessage.setFlag(Flag.DELETED, true);
                         if (Expunge.EXPUNGE_IMMEDIATELY == account.getExpungePolicy()) {
-                            remoteFolder.expunge();
+                            remoteFolder.expungeUids(Collections.singletonList(remoteMessage.getUid()));
                         }
                     }
                 }
@@ -1914,7 +1914,11 @@ void processPendingMoveOrCopy(PendingMoveOrCopy command, Account account) throws
             }
             if (!isCopy && Expunge.EXPUNGE_IMMEDIATELY == account.getExpungePolicy()) {
                 Timber.i("processingPendingMoveOrCopy expunging folder %s:%s", account.getDescription(), srcFolder);
-                remoteSrcFolder.expunge();
+                List<String> movedUids = new ArrayList<>(messages.size());
+                for (Message message : messages) {
+                    movedUids.add(message.getUid());
+                }
+                remoteSrcFolder.expungeUids(movedUids);
             }
 
             /*