textscreen: Fix use-after-free with mouse press.

When propagating mouse button presses to widgets within the window,
return from MouseButtonPress() immediately, or we will fall through
to additional code that references the window structure. If the
handler for the widget we clicked on closes the window, this will
have been freed.

This fixed #439. Thanks to DuClare for telling me about this.

1 files changed, 2 insertions, 2 deletions

diff --git a/textscreen/txt_window.c b/textscreen/txt_window.c
index 1d925beb..7fe83662 100644
--- a/textscreen/txt_window.c
+++ b/textscreen/txt_window.c
@@ -402,6 +402,7 @@ static void MouseButtonPress(txt_window_t *window, int b)
      && y >= widgets->y && y < (signed) (widgets->y + widgets->h))
     {
         TXT_WidgetMousePress(window, x, y, b);
+        return;
     }
 
     // Was one of the action area buttons pressed?
@@ -428,8 +429,7 @@ static void MouseButtonPress(txt_window_t *window, int b)
             // Pass through mouse press.
 
             TXT_WidgetMousePress(widget, x, y, b);
-
-            break;
+            return;
         }
     }
 }