patch 8.0.1795: lose contact with jobs when :gui forks

Problem:    Lose contact with jobs when :gui forks.
Solution:   Don't fork when there is a running job. Make log message for a
            died job clearer.  Also close the terminal when stderr and stdout
            are the same FD.

src/channel.c

@@ -485,7 +485,7 @@ channel_read_fd(int fd)
  */
 #ifdef FEAT_GUI_X11
     static void
-messageFromServer(XtPointer clientData,
+messageFromServerX11(XtPointer clientData,
 		  int *unused1 UNUSED,
 		  XtInputId *unused2 UNUSED)
 {
@@ -496,7 +496,7 @@ messageFromServer(XtPointer clientData,
 #ifdef FEAT_GUI_GTK
 # if GTK_CHECK_VERSION(3,0,0)
     static gboolean
-messageFromServer(GIOChannel *unused1 UNUSED,
+messageFromServerGtk3(GIOChannel *unused1 UNUSED,
 		  GIOCondition unused2 UNUSED,
 		  gpointer clientData)
 {
@@ -506,7 +506,7 @@ messageFromServer(GIOChannel *unused1 UNUSED,
 }
 # else
     static void
-messageFromServer(gpointer clientData,
+messageFromServerGtk2(gpointer clientData,
 		  gint unused1 UNUSED,
 		  GdkInputCondition unused2 UNUSED)
 {
@@ -526,41 +526,48 @@ channel_gui_register_one(channel_T *channel, ch_part_T part)
 	return;
 
 # ifdef FEAT_GUI_X11
-    /* Tell notifier we are interested in being called
-     * when there is input on the editor connection socket. */
+    /* Tell notifier we are interested in being called when there is input on
+     * the editor connection socket. */
     if (channel->ch_part[part].ch_inputHandler == (XtInputId)NULL)
+    {
+	ch_log(channel, "Registering part %s with fd %d",
+		part_names[part], channel->ch_part[part].ch_fd);
+
 	channel->ch_part[part].ch_inputHandler = XtAppAddInput(
 		(XtAppContext)app_context,
 		channel->ch_part[part].ch_fd,
 		(XtPointer)(XtInputReadMask + XtInputExceptMask),
-		messageFromServer,
+		messageFromServerX11,
 		(XtPointer)(long)channel->ch_part[part].ch_fd);
+    }
 # else
 #  ifdef FEAT_GUI_GTK
-    /* Tell gdk we are interested in being called when there
-     * is input on the editor connection socket. */
+    /* Tell gdk we are interested in being called when there is input on the
+     * editor connection socket. */
     if (channel->ch_part[part].ch_inputHandler == 0)
-#   if GTK_CHECK_VERSION(3,0,0)
     {
+	ch_log(channel, "Registering part %s with fd %d",
+		part_names[part], channel->ch_part[part].ch_fd);
+#   if GTK_CHECK_VERSION(3,0,0)
 	GIOChannel *chnnl = g_io_channel_unix_new(
 		(gint)channel->ch_part[part].ch_fd);
 
 	channel->ch_part[part].ch_inputHandler = g_io_add_watch(
 		chnnl,
 		G_IO_IN|G_IO_HUP|G_IO_ERR|G_IO_PRI,
-		messageFromServer,
+		messageFromServerGtk3,
 		GINT_TO_POINTER(channel->ch_part[part].ch_fd));
 
 	g_io_channel_unref(chnnl);
-    }
 #   else
 	channel->ch_part[part].ch_inputHandler = gdk_input_add(
 		(gint)channel->ch_part[part].ch_fd,
 		(GdkInputCondition)
 			     ((int)GDK_INPUT_READ + (int)GDK_INPUT_EXCEPTION),
-		messageFromServer,
+		messageFromServerGtk2,
 		(gpointer)(long)channel->ch_part[part].ch_fd);
 #   endif
+    }
 #  endif
 # endif
 }
@@ -598,6 +605,7 @@ channel_gui_unregister_one(channel_T *channel, ch_part_T part)
 # ifdef FEAT_GUI_X11
     if (channel->ch_part[part].ch_inputHandler != (XtInputId)NULL)
     {
+	ch_log(channel, "Unregistering part %s", part_names[part]);
 	XtRemoveInput(channel->ch_part[part].ch_inputHandler);
 	channel->ch_part[part].ch_inputHandler = (XtInputId)NULL;
     }
@@ -605,6 +613,7 @@ channel_gui_unregister_one(channel_T *channel, ch_part_T part)
 #  ifdef FEAT_GUI_GTK
     if (channel->ch_part[part].ch_inputHandler != 0)
     {
+	ch_log(channel, "Unregistering part %s", part_names[part]);
 #   if GTK_CHECK_VERSION(3,0,0)
 	g_source_remove(channel->ch_part[part].ch_inputHandler);
 #   else
@@ -3245,7 +3254,16 @@ ch_close_part_on_error(
 			      (int)STRLEN(DETACH_MSG_RAW), FALSE, "PUT ");
 
     /* When reading is not possible close this part of the channel.  Don't
-     * close the channel yet, there may be something to read on another part. */
+     * close the channel yet, there may be something to read on another part.
+     * When stdout and stderr use the same FD we get the error only on one of
+     * them, also close the other. */
+    if (part == PART_OUT || part == PART_ERR)
+    {
+	ch_part_T other = part == PART_OUT ? PART_ERR : PART_OUT;
+
+	if (channel->ch_part[part].ch_fd == channel->ch_part[other].ch_fd)
+	    ch_close_part(channel, other);
+    }
     ch_close_part(channel, part);
 
 #ifdef FEAT_GUI
@@ -5115,6 +5133,22 @@ job_still_useful(job_T *job)
     return job_need_end_check(job) || job_channel_still_useful(job);
 }
 
+#if defined(GUI_MAY_FORK) || defined(PROTO)
+/*
+ * Return TRUE when there is any running job that we care about.
+ */
+    int
+job_any_running()
+{
+    job_T	*job;
+
+    for (job = first_job; job != NULL; job = job->jv_next)
+	if (job_still_useful(job))
+	    return TRUE;
+    return FALSE;
+}
+#endif
+
 #if !defined(USE_ARGV) || defined(PROTO)
 /*
  * Escape one argument for an external command.