Bug#860927: Tk applications segmentation fault when ibus-daemon IME is restarted

[Jonathan Nieder]

Package: tk8.6
Version: 8.6.1-3ubuntu2
Severity: important
Tags: upstream patch
Forwarded: http://core.tcl.tk/tk/tktview?name=7d967c68a0

Hi,

Steve Paik (cc-ed) reported that gitk is crashing periodically.  This
patch, from upstream tk, should fix it.

Thoughts?

Please forgive the whitespace damage.  Copy/paste was the simplest way
to get this here.

Thanks,
Jonathan

commit 0175bc1be685a5ce4a92f7c153eb12e28c28cb1d (origin/bug_7d967c68)
Author: jan.nijtmans <nijtm...@users.sourceforge.net>
Date:   Thu Dec 15 16:07:06 2016 +0000

    Proposed fix for [7d967c68a09e07e355358af40f36dd5dd84c7022|7d967c68]: Tk 
applications segmentation fault when ibus-daemon IME is restarted

diff --git a/generic/tkEvent.c b/generic/tkEvent.c
index 95aeda1dd..d058e7cd6 100644
--- a/generic/tkEvent.c
+++ b/generic/tkEvent.c
@@ -356,6 +356,7 @@ CreateXIC(
        /* XCreateIC failed. */
        return;
     }
+    winPtr->ximGeneration = dispPtr->ximGeneration;
 
     /*
      * Adjust the window's event mask if the IM requires it.
@@ -1288,6 +1289,14 @@ Tk_HandleEvent(
      */
 
 #ifdef TK_USE_INPUT_METHODS
+    /*
+     * If the XIC has been invalidated, it must be recreated.
+     */
+    if (winPtr->dispPtr->ximGeneration != winPtr->ximGeneration) {
+       winPtr->flags &= ~TK_CHECKED_IC;
+       winPtr->inputContext = NULL;
+    }
+
     if ((winPtr->dispPtr->flags & TK_DISPLAY_USE_IM)) {
        if (!(winPtr->flags & (TK_CHECKED_IC|TK_ALREADY_DEAD))) {
            winPtr->flags |= TK_CHECKED_IC;
@@ -1295,7 +1304,9 @@ Tk_HandleEvent(
                CreateXIC(winPtr);
            }
        }
-       if (eventPtr->type == FocusIn && winPtr->inputContext != NULL) {
+       if ((eventPtr->type == FocusIn) &&
+               (winPtr->dispPtr->inputMethod != NULL) &&
+               (winPtr->inputContext != NULL)) {
            XSetICFocus(winPtr->inputContext);
        }
     }

commit 596abb7b53897447dda6044725ea94a664dae64e
Author: jan.nijtmans <nijtm...@users.sourceforge.net>
Date:   Fri Feb 10 11:38:55 2017 +0000

    Fix [7d967c68a09e07e355358af40f36dd5dd84c7022|7d967c68a0] follow-up: Tk 
applications segmentation fault when ibus-daemon IME is restarted. Patch by 
Brad Lanam.

diff --git a/generic/tkWindow.c b/generic/tkWindow.c
index e4d696bdd..690a8412d 100644
--- a/generic/tkWindow.c
+++ b/generic/tkWindow.c
@@ -475,9 +475,6 @@ GetScreen(
            dispPtr->cursorFont = None;
            dispPtr->warpWindow = NULL;
            dispPtr->multipleAtom = None;
-#ifdef TK_USE_INPUT_METHODS
-           dispPtr->ximGeneration = 0;
-#endif /*TK_USE_INPUT_METHODS*/
 
            /*
             * By default we do want to collapse motion events in
@@ -656,6 +653,7 @@ TkAllocWindow(
     winPtr->flags = 0;
     winPtr->handlerList = NULL;
 #ifdef TK_USE_INPUT_METHODS
+    winPtr->ximGeneration = 0;
     winPtr->inputContext = NULL;
 #endif /* TK_USE_INPUT_METHODS */
     winPtr->tagPtr = NULL;