bug 1272194 explicitly invalidate after change style contexts belonging to widgets r=stransky+263117

This fixes menu item rendering during hover.

MozReview-Commit-ID: CEa6aorqBZM

--HG--
extra : rebase_source : 19b1d4f26541b8b5a435252552352592791c080d

widget/gtk/WidgetStyleCache.cpp

@@ -280,13 +280,32 @@ GtkStyleContext*
 ClaimStyleContext(WidgetNodeType aNodeType, GtkTextDirection aDirection,
                   GtkStateFlags aStateFlags, StyleFlags aFlags)
 {
+  MOZ_ASSERT(!sStyleContextNeedsRestore);
   GtkStyleContext* style = GetStyleInternal(aNodeType);
 #ifdef DEBUG
   MOZ_ASSERT(!sCurrentStyleContext);
   sCurrentStyleContext = style;
 #endif
-  gtk_style_context_set_state(style, aStateFlags);
-  gtk_style_context_set_direction(style, aDirection);
+  GtkStateFlags oldState = gtk_style_context_get_state(style);
+  GtkTextDirection oldDirection = gtk_style_context_get_direction(style);
+  if (oldState != aStateFlags || oldDirection != aDirection) {
+    // From GTK 3.8, set_state() will overwrite the direction, so set
+    // direction after state.
+    gtk_style_context_set_state(style, aStateFlags);
+    gtk_style_context_set_direction(style, aDirection);
+
+    // This invalidate is necessary for unsaved style contexts from GtkWidgets
+    // in pre-3.18 GTK, because automatic invalidation of such contexts
+    // was delayed until a resize event runs.
+    //
+    // https://bugzilla.mozilla.org/show_bug.cgi?id=1272194#c7
+    //
+    // Avoid calling invalidate on saved contexts to avoid performing
+    // build_properties() (in 3.16 stylecontext.c) unnecessarily early.
+    if (!sStyleContextNeedsRestore) {
+      gtk_style_context_invalidate(style);
+    }
+  }
   return style;
 }
 

widget/gtk/mozgtk/mozgtk.c

@@ -548,6 +548,7 @@ STUB(gtk_style_context_get_background_color)
 STUB(gtk_style_context_get_border)
 STUB(gtk_style_context_get_border_color)
 STUB(gtk_style_context_get_color)
+STUB(gtk_style_context_get_direction)
 STUB(gtk_style_context_get_margin)
 STUB(gtk_style_context_get_padding)
 STUB(gtk_style_context_get_path)
@@ -555,6 +556,7 @@ STUB(gtk_style_context_get_property)
 STUB(gtk_style_context_get_state)
 STUB(gtk_style_context_get_style)
 STUB(gtk_style_context_has_class)
+STUB(gtk_style_context_invalidate)
 STUB(gtk_style_context_new)
 STUB(gtk_style_context_remove_class)
 STUB(gtk_style_context_remove_region)