Fixed the same oversight as the previous commit on the Windows and OS X backends. Added comments to document the oversight.

new/darwin/container.m

@@ -112,6 +112,9 @@ static void containerShow(uiControl *cc)
 	containerView *c = (containerView *) (cc->Internal);
 
 	[c setHidden:NO];
+	// hidden controls don't count in boxes and grids
+	if (c.containerParent != NULL)
+		uiContainerUpdate(c.containerParent);
 	c.containerHidden = 0;
 }
 
@@ -120,6 +123,8 @@ static void containerHide(uiControl *cc)
 	containerView *c = (containerView *) (cc->Internal);
 
 	[c setHidden:YES];
+	if (c.containerParent != NULL)
+		uiContainerUpdate(c.containerParent);
 	c.containerHidden = 1;
 }
 

new/unix/container.c

@@ -177,6 +177,7 @@ static void containerShow(uiControl *cc)
 
 	// don't use gtk_widget_show_all(); that'll show every widget, including ones hidden by the user
 	gtk_widget_show(GTK_WIDGET(c));
+	// hidden controls don't count in boxes and grids
 	if (c->parent != NULL)
 		uiContainerUpdate(c->parent);
 	c->hidden = 0;

new/windows/container.c

@@ -178,6 +178,9 @@ static void containerShow(uiControl *cc)
 	struct container *c = (struct container *) (cc->Internal);
 
 	ShowWindow(c->hwnd, SW_SHOW);
+	// hidden controls don't count in boxes and grids
+	if (c->parent != NULL)
+		uiContainerUpdate(c->parent);
 	c->hidden = 0;
 }
 
@@ -186,6 +189,8 @@ static void containerHide(uiControl *cc)
 	struct container *c = (struct container *) (cc->Internal);
 
 	ShowWindow(c->hwnd, SW_HIDE);
+	if (c->parent != NULL)
+		uiContainerUpdate(c->parent);
 	c->hidden = 1;
 }