Changeset 192724 in webkit

Timestamp:

Nov 21, 2015 9:00:00 AM (8 years ago)

Author:

Michael Catanzaro

Message:

[GTK] Off-by-one error in getStyleContext()
​https://bugs.webkit.org/show_bug.cgi?id=151524

Reviewed by Carlos Garcia Campos.

GtkWidgetPath* path = gtk_widget_path_new();
gtk_widget_path_append_type(path, widgetType);
...
gtk_widget_path_iter_add_class(path, 0, GTK_STYLE_CLASS_BUTTON);
gtk_widget_path_iter_add_class(path, 1, "text-button");

Only one widget type was appended to the widget path, so the maximum valid index is 0. This
code means to add both style classes to the first widget type in the widget path, so the
second call should use index 0 rather than index 1.

This caused no bug in practice, because when the index is invalid,
gtk_widget_path_iter_add_class() automatically changes the index to the last valid position
in the widget path -- in this case, 0. This is routinely done with -1 as a convention for
specifying the last position in the widget path.

• rendering/RenderThemeGtk.cpp:

(WebCore::getStyleContext):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• rendering/RenderThemeGtk.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2015-11-21  Michael Catanzaro  <mcatanzaro@igalia.com>
+
+        [GTK] Off-by-one error in getStyleContext()
+        https://bugs.webkit.org/show_bug.cgi?id=151524
+
+        Reviewed by Carlos Garcia Campos.
+
+        GtkWidgetPath* path = gtk_widget_path_new();
+        gtk_widget_path_append_type(path, widgetType);
+        // ...
+        gtk_widget_path_iter_add_class(path, 0, GTK_STYLE_CLASS_BUTTON);
+        gtk_widget_path_iter_add_class(path, 1, "text-button");
+
+        Only one widget type was appended to the widget path, so the maximum valid index is 0. This
+        code means to add both style classes to the first widget type in the widget path, so the
+        second call should use index 0 rather than index 1.
+
+        This caused no bug in practice, because when the index is invalid,
+        gtk_widget_path_iter_add_class() automatically changes the index to the last valid position
+        in the widget path -- in this case, 0. This is routinely done with -1 as a convention for
+        specifying the last position in the widget path.
+
+        * rendering/RenderThemeGtk.cpp:
+        (WebCore::getStyleContext):
+
 2015-11-21  Michael Catanzaro  <mcatanzaro@igalia.com>
 

trunk/Source/WebCore/rendering/RenderThemeGtk.cpp

@@ -176 +176 @@
     else if (widgetType == GTK_TYPE_BUTTON) {
         gtk_widget_path_iter_add_class(path, 0, GTK_STYLE_CLASS_BUTTON);
-        gtk_widget_path_iter_add_class(path, 1, "text-button");
+        gtk_widget_path_iter_add_class(path, 0, "text-button");
     } else if (widgetType == GTK_TYPE_SCALE)
         gtk_widget_path_iter_add_class(path, 0, GTK_STYLE_CLASS_SCALE);