patch 7.4.1451

Problem:    Vim hangs when a channel has a callback but isn't referenced.
Solution:   Have channel_unref() only return TRUE when the channel was
            actually freed.

src/channel.c

@@ -334,12 +334,17 @@ channel_still_useful(channel_T *channel)
  * Close a channel and free all its resources if there is no further action
  * possible, there is no callback to be invoked or the associated job was
  * killed.
+ * Return TRUE if the channel was freed.
  */
-    void
+    int
 channel_may_free(channel_T *channel)
 {
     if (!channel_still_useful(channel))
+    {
 	channel_free(channel);
+	return TRUE;
+    }
+    return FALSE;
 }
 
 /*

src/eval.c

@@ -7747,10 +7747,7 @@ failret:
 channel_unref(channel_T *channel)
 {
     if (channel != NULL && --channel->ch_refcount <= 0)
-    {
+	return channel_may_free(channel);
-	channel_may_free(channel);
-	return TRUE;
-    }
     return FALSE;
 }
 #endif

src/proto/channel.pro

@@ -4,7 +4,7 @@ int ch_log_active(void);
 void ch_log(channel_T *ch, char *msg);
 void ch_logs(channel_T *ch, char *msg, char *name);
 channel_T *add_channel(void);
-void channel_may_free(channel_T *channel);
+int channel_may_free(channel_T *channel);
 void channel_free(channel_T *channel);
 void channel_gui_register(channel_T *channel);
 void channel_gui_register_all(void);

src/version.c

@@ -743,6 +743,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1451,
 /**/
     1450,
 /**/