Fixed connection pool lock

app/src/main/java/com/sun/mail/imap/IMAPFolder.java

@@ -3963,7 +3963,8 @@ public class IMAPFolder extends Folder implements UIDFolder, ResponseHandler {
 		protocol.noop(); 
 	}
 
-        if (keepStoreAlive && ((IMAPStore)store).hasSeparateStoreConnection()) {
+        if (keepStoreAlive && ((IMAPStore)store).hasSeparateStoreConnection() &&
+				!((IMAPStore)store).isStoreConnectionInUse()) {
             IMAPProtocol p = null;
 	    try {
 		p = ((IMAPStore)store).getFolderStoreProtocol();

app/src/main/java/com/sun/mail/imap/IMAPStore.java

@@ -1264,7 +1264,11 @@ public class IMAPStore extends Store
         return pool.separateStoreConnection;
     }
 
-    /** 
+    boolean isStoreConnectionInUse() {
+		return pool.storeConnectionInUse;
+	}
+
+    /**
      * Return the connection pool logger.
      */ 
     MailLogger getConnectionPoolLogger() {

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

@@ -2286,7 +2286,6 @@ public class MessageHelper {
 
     static int getMessageCount(Folder folder) throws MessagingException {
         // Keep alive
-        int total = folder.getMessageCount();
         try {
             int count = 0;
             for (Message message : folder.getMessages())
@@ -2295,8 +2294,8 @@ public class MessageHelper {
 
             return count;
         } catch (Throwable ex) {
-            Log.w(ex);
-            return total;
+            Log.e(ex);
+            return -1;
         }
     }