[geary/wip/26-proton-mail-bridge] Ensure IDLE is not sent after is it is disabled for a connection.

[Michael Gratton <mjog src gnome org>]

commit 2e26d5b4723d286b7000e160df4f66ea29e68e2d
Author: Michael James Gratton <mike vee net>
Date:   Fri Jul 13 10:58:29 2018 +1000

    Ensure IDLE is not sent after is it is disabled for a connection.
    
    Since the idle timer was not being cancelled, when idle_when_quiet was
    set to false the connection would still send IDLE. This also removes the
    need to send a NOOP to get in/out of IDLE.

 .../imap/transport/imap-client-connection.vala     | 45 +++++++++++++++-------
 src/engine/imap/transport/imap-client-session.vala | 11 ++----
 2 files changed, 36 insertions(+), 20 deletions(-)
---
diff --git a/src/engine/imap/transport/imap-client-connection.vala 
b/src/engine/imap/transport/imap-client-connection.vala
index 3e4e4429..bde973d1 100644
--- a/src/engine/imap/transport/imap-client-connection.vala
+++ b/src/engine/imap/transport/imap-client-connection.vala
@@ -64,14 +64,8 @@ public class Geary.Imap.ClientConnection : BaseObject {
      * resorting to NOOP keepalives.  (Note that keepalives are still
      * required to hold the connection open, according to the IMAP
      * specification.)
-     *
-     * Note that setting this false will *not* break a connection out
-     * of IDLE state alone; a command needs to be flushed down the
-     * pipe to do that.  (NOOP would be a good choice.)  Nor will this
-     * initiate an IDLE command either; it can only do that after
-     * sending a command (again, NOOP would be a good choice).
      */
-    public bool idle_when_quiet = false;
+    public bool idle_when_quiet { get; private set; default = false; }
 
     private Geary.Endpoint endpoint;
     private SocketConnection? cx = null;
@@ -198,6 +192,28 @@ public class Geary.Imap.ClientConnection : BaseObject {
         return (this.current_command is IdleCommand);
     }
 
+    /**
+     * Sets whether this connection should automatically IDLE.
+     *
+     * If true, this will cause the connection to send an IDLE command
+     * when no other commands have been sent after a short period of
+     * time
+     *
+     * If false, any existing IDLE command will be cancelled, and the
+     * connection will no longer be automatically sent.
+     */
+    public void enable_idle_when_quiet(bool do_idle) {
+        this.idle_when_quiet = do_idle;
+        if (do_idle) {
+            if (!this.idle_timer.is_running) {
+                this.idle_timer.start();
+            }
+        } else {
+            this.idle_timer.reset();
+            exit_idle();
+        }
+    }
+
     /**
      * Returns silently if a connection is already established.
      */
@@ -302,12 +318,8 @@ public class Geary.Imap.ClientConnection : BaseObject {
 
         this.pending_queue.send(new_command);
 
-        // If the current command is an IDLE, tell it to exit so we
-        // can get on with life.
-        IdleCommand? idle = this.current_command as IdleCommand;
-        if (idle != null) {
-            idle.exit_idle();
-        }
+        // Exit IDLE so we can get on with life
+        exit_idle();
     }
 
     public string to_string() {
@@ -374,6 +386,13 @@ public class Geary.Imap.ClientConnection : BaseObject {
         }
     }
 
+    private inline void exit_idle() {
+        IdleCommand? idle = this.current_command as IdleCommand;
+        if (idle != null) {
+            idle.exit_idle();
+        }
+    }
+
     // Generates a unique tag for the IMAP connection in the form of
     // "<a-z><000-999>".
     private Tag generate_tag() {
diff --git a/src/engine/imap/transport/imap-client-session.vala 
b/src/engine/imap/transport/imap-client-session.vala
index 239c48c7..b65b357a 100644
--- a/src/engine/imap/transport/imap-client-session.vala
+++ b/src/engine/imap/transport/imap-client-session.vala
@@ -1129,8 +1129,7 @@ public class Geary.Imap.ClientSession : BaseObject {
             case ProtocolState.AUTHORIZED:
             case ProtocolState.SELECTED:
             case ProtocolState.SELECTING:
-                this.cx.idle_when_quiet = true;
-                yield send_command_async(new NoopCommand(), cancellable);
+                this.cx.enable_idle_when_quiet(true);
                 break;
 
             default:
@@ -1403,9 +1402,7 @@ public class Geary.Imap.ClientSession : BaseObject {
                 debug("[%s]: Unable to SELECT/EXAMINE: %s", to_string(), completion_response.to_string());
 
                 // turn off IDLE, client should request it again if desired.
-                if (cx.idle_when_quiet) {
-                    cx.idle_when_quiet = false;
-                }
+                this.cx.enable_idle_when_quiet(false);
 
                 return State.AUTHORIZED;
         }
@@ -1439,7 +1436,7 @@ public class Geary.Imap.ClientSession : BaseObject {
             return state;
 
         // returning to AUTHORIZED state, turn off IDLE
-        cx.idle_when_quiet = false;
+        this.cx.enable_idle_when_quiet(false);
 
         return State.CLOSING_MAILBOX;
     }
@@ -1496,7 +1493,7 @@ public class Geary.Imap.ClientSession : BaseObject {
             return state;
 
         // Leaving AUTHORIZED state, turn off IDLE
-        cx.idle_when_quiet = false;
+        this.cx.enable_idle_when_quiet(false);
 
         return State.LOGGING_OUT;
     }