Handle weird reparenting cases.

3 files changed, 42 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index 22ebaba..e42ad7f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2009-12-06  Gary Wong  <gtw@gnu.org>
+
+	* root.c (root_reparent_notify): Handle cases where a window is
+	"reparented" to its current parent.
+
+	* window-table.c (stack_move_above): Treat moving a window above
+	itself as a no-op.
+	(stack_insert_singleton, stack_insert_above, stack_remove)
+	(stack_move_above): Add extra assertions.
+
 2009-09-11  Gary Wong  <gtw@gnu.org>
 
 	* decorate-core.c (decorate_core_init): Moved to the initialisation
diff --git a/root.c b/root.c
index 6f468c3..14ece34 100644
--- a/root.c
+++ b/root.c
@@ -129,11 +129,18 @@ static void root_destroy_notify( struct gwm_window *window,
 static void root_reparent_notify( struct gwm_window *window,
 				  xcb_reparent_notify_event_t *ev ) {
 
-    if( ev->parent == window->w )
-	stack_insert_above( &window_stack, ev->window,
-			    stack_lookup( &window_stack, window->w |
-					  STACK_END )->lower_window );
-    else
+    if( ev->parent == window->w ) {
+	/* It's possible to reparent a window to its current parent,
+	   so we can't assume the window is not already in the stack. */
+	if( stack_lookup( &window_stack, ev->window ) )
+	    stack_move_above( &window_stack, ev->window,
+			      stack_lookup( &window_stack, window->w |
+					    STACK_END )->lower_window );
+	else
+	    stack_insert_above( &window_stack, ev->window,
+				stack_lookup( &window_stack, window->w |
+					      STACK_END )->lower_window );
+    } else
 	stack_remove( &window_stack, ev->window );
 }
 
diff --git a/window-table.c b/window-table.c
index fb71d86..981d6b1 100644
--- a/window-table.c
+++ b/window-table.c
@@ -495,7 +495,12 @@ static void stack_insert_new( struct window_stack *stack, xcb_window_t window,
 extern void stack_insert_singleton( struct window_stack *stack,
 				    xcb_window_t key ) {
 
+    if( !key )
+	return;
+
     stack_insert_new( stack, key, key, key );
+
+    assert( stack_lookup( stack, key ) );
 }
 
 extern void stack_insert_above( struct window_stack *stack,
@@ -504,6 +509,9 @@ extern void stack_insert_above( struct window_stack *stack,
     struct stacking_order *l, *h;
     xcb_window_t higher_window;
 
+    if( !key )
+	return;
+
     l = stack_lookup( stack, lower_window );
     assert( l );
     higher_window = l->higher_window;
@@ -515,6 +523,10 @@ extern void stack_insert_above( struct window_stack *stack,
     h = stack_lookup( stack, higher_window );
     h->lower_window = key;
     l->higher_window = key;
+
+    assert( stack_lookup( stack, key ) );
+    assert( l );
+    assert( h );
 }
 
 extern void stack_remove( struct window_stack *stack, xcb_window_t window ) {
@@ -546,9 +558,14 @@ extern void stack_remove( struct window_stack *stack, xcb_window_t window ) {
 		/* Load becoming low: resize. */
 		stack_rehash( stack, stack->hash, stack->n >> 1,
 			      stack->max - 4 );
+
+	    assert( !stack_lookup( stack, window ) );
+
 	    return;
 	}
     }
+
+    assert( FALSE );
 }
 
 extern void stack_move_above( struct window_stack *stack,
@@ -557,7 +574,7 @@ extern void stack_move_above( struct window_stack *stack,
 
     struct stacking_order *l, *h, *entry;
 
-    if( !window )
+    if( !window || window == lower_window )
 	return;
 
     entry = stack_lookup( stack, window );
@@ -585,6 +602,8 @@ extern void stack_move_above( struct window_stack *stack,
     l->higher_window = window;
     entry->lower_window = lower_window;
     entry->higher_window = h->window;
+
+    assert( stack_lookup( stack, window ) );
 }
 
 extern xcb_window_t stack_real_below( struct window_stack *stack,