(svn r27085) -Fix: Always return a valid window to the world generation gui code.

2 files changed, 7 insertions, 4 deletions

diff --git a/src/genworld_gui.cpp b/src/genworld_gui.cpp
index 6ea4b5f62..603fef90d 100644
--- a/src/genworld_gui.cpp
+++ b/src/genworld_gui.cpp
@@ -837,7 +837,8 @@ static void _ShowGenerateLandscape(GenenerateLandscapeWindowMode mode)
 		if (!GetHeightmapDimensions(_file_to_saveload.name, &x, &y)) return;
 	}
 
-	GenerateLandscapeWindow *w = AllocateWindowDescFront<GenerateLandscapeWindow>((mode == GLWM_HEIGHTMAP) ? &_heightmap_load_desc : &_generate_landscape_desc, mode);
+	WindowDesc *desc = (mode == GLWM_HEIGHTMAP) ? &_heightmap_load_desc : &_generate_landscape_desc;
+	GenerateLandscapeWindow *w = AllocateWindowDescFront<GenerateLandscapeWindow>(desc, mode, true);
 
 	if (mode == GLWM_HEIGHTMAP) {
 		w->x = x;
diff --git a/src/window_gui.h b/src/window_gui.h
index 539156560..70b80c682 100644
--- a/src/window_gui.h
+++ b/src/window_gui.h
@@ -851,12 +851,14 @@ Window *FindWindowFromPt(int x, int y);
  * @tparam Wcls %Window class to use if the window does not exist.
  * @param desc The pointer to the WindowDesc to be created
  * @param window_number the window number of the new window
- * @return %Window pointer of the newly created window, or \c NULL.
+ * @param return_existing If set, also return the window if it already existed.
+ * @return %Window pointer of the newly created window, or the existing one if \a return_existing is set, or \c NULL.
  */
 template <typename Wcls>
-Wcls *AllocateWindowDescFront(WindowDesc *desc, int window_number)
+Wcls *AllocateWindowDescFront(WindowDesc *desc, int window_number, bool return_existing = false)
 {
-	if (BringWindowToFrontById(desc->cls, window_number)) return NULL;
+	Wcls *w = static_cast<Wcls *>(BringWindowToFrontById(desc->cls, window_number));
+	if (w != NULL) return return_existing ? w : NULL;
 	return new Wcls(desc, window_number);
 }