Check folder capability

app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java

@@ -374,7 +374,7 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
                                 // https://tools.ietf.org/html/rfc3501#section-6.4.4
                                 if (criteria.query != null &&
                                         criteria.query.startsWith("raw:") &&
-                                        state.iservice.hasCapability("X-GM-EXT-1") &&
+                                        protocol.hasCapability("X-GM-EXT-1") &&
                                         EntityFolder.ARCHIVE.equals(browsable.type)) {
                                     // https://support.google.com/mail/answer/7190
                                     // https://developers.google.com/gmail/imap/imap-extensions#extension_of_the_search_command_x-gm-raw

app/src/main/java/eu/faircode/email/Core.java

@@ -873,7 +873,7 @@ class Core {
 
         // Add message
         Long newuid = null;
-        if (istore.hasCapability("UIDPLUS")) {
+        if (MessageHelper.hasCapability(ifolder, "UIDPLUS")) {
             // https://tools.ietf.org/html/rfc4315
             AppendUID[] uids = ifolder.appendUIDMessages(new Message[]{imessage});
             if (uids != null && uids.length > 0 && uids[0] != null && uids[0].uid > 0) {
@@ -956,12 +956,7 @@ class Core {
             }
 
         // Some servers return different capabilities for different sessions
-        boolean canMove = (Boolean) ifolder.doCommand(new IMAPFolder.ProtocolCommand() {
-            @Override
-            public Object doCommand(IMAPProtocol protocol) throws ProtocolException {
-                return protocol.hasCapability("MOVE");
-            }
-        });
+        boolean canMove = MessageHelper.hasCapability(ifolder, "MOVE");
 
         // Some providers do not support the COPY operation for drafts
         boolean draft = (EntityFolder.DRAFTS.equals(folder.type) || EntityFolder.DRAFTS.equals(target.type));

app/src/main/java/eu/faircode/email/MessageHelper.java

@@ -29,8 +29,10 @@ import androidx.documentfile.provider.DocumentFile;
 import androidx.preference.PreferenceManager;
 
 import com.sun.mail.gimap.GmailMessage;
+import com.sun.mail.iap.ProtocolException;
 import com.sun.mail.imap.IMAPFolder;
 import com.sun.mail.imap.IMAPMessage;
+import com.sun.mail.imap.protocol.IMAPProtocol;
 import com.sun.mail.util.ASCIIUtility;
 import com.sun.mail.util.BASE64DecoderStream;
 import com.sun.mail.util.FolderClosedIOException;
@@ -2313,6 +2315,16 @@ public class MessageHelper {
         }
     }
 
+    static boolean hasCapability(IMAPFolder ifolder, final String capability) throws MessagingException {
+        // Folder can have different capabilities than the store
+        return (boolean) ifolder.doCommand(new IMAPFolder.ProtocolCommand() {
+            @Override
+            public Object doCommand(IMAPProtocol protocol) throws ProtocolException {
+                return protocol.hasCapability(capability);
+            }
+        });
+    }
+
     static String sanitizeKeyword(String keyword) {
         // https://tools.ietf.org/html/rfc3501
         StringBuilder sb = new StringBuilder();

app/src/main/java/eu/faircode/email/ServiceSynchronize.java

@@ -1097,6 +1097,9 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                             db.folder().setFolderState(folder.id, "connected");
                             db.folder().setFolderError(folder.id, null);
 
+                            if (capIdle != MessageHelper.hasCapability(ifolder, "IDLE"))
+                                Log.e("Conflicting IDLE=" + capIdle + " host=" + account.host);
+
                             int count = MessageHelper.getMessageCount(ifolder);
                             db.folder().setFolderTotal(folder.id, count < 0 ? null : count);