[gtk+] css: Ensure the tree built is always the same

[Alexander Larsson <alexl src gnome org>]

commit 146b6f3a93f3a1f969240a494b5e3ab03815391d
Author: Alexander Larsson <alexl redhat com>
Date:   Thu Nov 29 16:20:14 2012 +0100

    css: Ensure the tree built is always the same
    
    We add some "artificial" ordering to the otherwise unordered
    tree nodes. This means the tree will be the same every time for the
    same input. This is good because e.g. tree order affects the
    reordering of the simple selectors, which may affect how
    css providers are printed, which need to be consistent for
    the css tests to work.

 gtk/gtkcssselector.c |  109 +++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 107 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkcssselector.c b/gtk/gtkcssselector.c
index 831b089..57dbb88 100644
--- a/gtk/gtkcssselector.c
+++ b/gtk/gtkcssselector.c
@@ -38,6 +38,8 @@ struct _GtkCssSelectorClass {
                                      const GtkCssMatcher        *matcher,
 				     GHashTable                  *res);
   GtkCssChange      (* get_change)  (const GtkCssSelector       *selector);
+  int               (* compare_one) (const GtkCssSelector       *a,
+				     const GtkCssSelector       *b);
 
   guint         increase_id_specificity :1;
   guint         increase_class_specificity :1;
@@ -121,6 +123,15 @@ gtk_css_selector_get_change (const GtkCssSelector *selector)
   return selector->class->get_change (selector);
 }
 
+static int
+gtk_css_selector_compare_one (const GtkCssSelector *a, const GtkCssSelector *b)
+{
+  if (a->class != b->class)
+    return strcmp (a->class->name, b->class->name);
+  else
+    return a->class->compare_one (a, b);
+}
+  
 static const GtkCssSelector *
 gtk_css_selector_previous (const GtkCssSelector *selector)
 {
@@ -177,6 +188,13 @@ gtk_css_selector_descendant_tree_match (const GtkCssSelectorTree *tree,
     }
 }
 
+static int
+gtk_css_selector_descendant_compare_one (const GtkCssSelector *a,
+					 const GtkCssSelector *b)
+{
+  return 0;
+}
+  
 static GtkCssChange
 gtk_css_selector_descendant_get_change (const GtkCssSelector *selector)
 {
@@ -189,6 +207,7 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_DESCENDANT = {
   gtk_css_selector_descendant_match,
   gtk_css_selector_descendant_tree_match,
   gtk_css_selector_descendant_get_change,
+  gtk_css_selector_descendant_compare_one,
   FALSE, FALSE, FALSE, FALSE, FALSE
 };
 
@@ -234,12 +253,20 @@ gtk_css_selector_child_get_change (const GtkCssSelector *selector)
   return _gtk_css_change_for_child (gtk_css_selector_get_change (gtk_css_selector_previous (selector)));
 }
 
+static int
+gtk_css_selector_child_compare_one (const GtkCssSelector *a,
+				    const GtkCssSelector *b)
+{
+  return 0;
+}
+
 static const GtkCssSelectorClass GTK_CSS_SELECTOR_CHILD = {
   "child",
   gtk_css_selector_child_print,
   gtk_css_selector_child_match,
   gtk_css_selector_child_tree_match,
   gtk_css_selector_child_get_change,
+  gtk_css_selector_child_compare_one,
   FALSE, FALSE, FALSE, FALSE, FALSE
 };
 
@@ -297,12 +324,21 @@ gtk_css_selector_sibling_get_change (const GtkCssSelector *selector)
   return _gtk_css_change_for_sibling (gtk_css_selector_get_change (gtk_css_selector_previous (selector)));
 }
 
+static int
+gtk_css_selector_sibling_compare_one (const GtkCssSelector *a,
+				      const GtkCssSelector *b)
+{
+  return 0;
+}
+  
+
 static const GtkCssSelectorClass GTK_CSS_SELECTOR_SIBLING = {
   "sibling",
   gtk_css_selector_sibling_print,
   gtk_css_selector_sibling_match,
   gtk_css_selector_sibling_tree_match,
   gtk_css_selector_sibling_get_change,
+  gtk_css_selector_sibling_compare_one,
   FALSE, FALSE, FALSE, FALSE, FALSE
 };
 
@@ -350,12 +386,20 @@ gtk_css_selector_adjacent_get_change (const GtkCssSelector *selector)
   return _gtk_css_change_for_sibling (gtk_css_selector_get_change (gtk_css_selector_previous (selector)));
 }
 
+static int
+gtk_css_selector_adjacent_compare_one (const GtkCssSelector *a,
+				       const GtkCssSelector *b)
+{
+  return 0;
+}
+
 static const GtkCssSelectorClass GTK_CSS_SELECTOR_ADJACENT = {
   "adjacent",
   gtk_css_selector_adjacent_print,
   gtk_css_selector_adjacent_match,
   gtk_css_selector_adjacent_tree_match,
   gtk_css_selector_adjacent_get_change,
+  gtk_css_selector_adjacent_compare_one,
   FALSE, FALSE, FALSE, FALSE, FALSE
 };
 
@@ -413,12 +457,20 @@ gtk_css_selector_any_get_change (const GtkCssSelector *selector)
   return gtk_css_selector_get_change (gtk_css_selector_previous (selector));
 }
 
+static int
+gtk_css_selector_any_compare_one (const GtkCssSelector *a,
+				  const GtkCssSelector *b)
+{
+  return 0;
+}
+
 static const GtkCssSelectorClass GTK_CSS_SELECTOR_ANY = {
   "any",
   gtk_css_selector_any_print,
   gtk_css_selector_any_match,
   gtk_css_selector_any_tree_match,
   gtk_css_selector_any_get_change,
+  gtk_css_selector_any_compare_one,
   FALSE, FALSE, FALSE, TRUE, TRUE
 };
 
@@ -464,12 +516,20 @@ gtk_css_selector_name_get_change (const GtkCssSelector *selector)
   return gtk_css_selector_get_change (gtk_css_selector_previous (selector)) | GTK_CSS_CHANGE_NAME;
 }
 
+static int
+gtk_css_selector_name_compare_one (const GtkCssSelector *a,
+				   const GtkCssSelector *b)
+{
+  return strcmp (a->data, b->data);
+}
+
 static const GtkCssSelectorClass GTK_CSS_SELECTOR_NAME = {
   "name",
   gtk_css_selector_name_print,
   gtk_css_selector_name_match,
   gtk_css_selector_name_tree_match,
   gtk_css_selector_name_get_change,
+  gtk_css_selector_name_compare_one,
   FALSE, FALSE, TRUE, TRUE, FALSE
 };
 
@@ -535,12 +595,20 @@ gtk_css_selector_region_get_change (const GtkCssSelector *selector)
   return change;
 }
 
+static int
+gtk_css_selector_region_compare_one (const GtkCssSelector *a,
+				     const GtkCssSelector *b)
+{
+  return strcmp (a->data, b->data);
+}
+
 static const GtkCssSelectorClass GTK_CSS_SELECTOR_REGION = {
   "region",
   gtk_css_selector_region_print,
   gtk_css_selector_region_match,
   gtk_css_selector_region_tree_match,
   gtk_css_selector_region_get_change,
+  gtk_css_selector_region_compare_one,
   FALSE, FALSE, TRUE, TRUE, TRUE
 };
 
@@ -586,12 +654,21 @@ gtk_css_selector_class_get_change (const GtkCssSelector *selector)
   return gtk_css_selector_get_change (gtk_css_selector_previous (selector)) | GTK_CSS_CHANGE_CLASS;
 }
 
+static int
+gtk_css_selector_class_compare_one (const GtkCssSelector *a,
+				    const GtkCssSelector *b)
+{
+  return strcmp (g_quark_to_string (GPOINTER_TO_UINT (a->data)),
+		 g_quark_to_string (GPOINTER_TO_UINT (b->data)));
+}
+
 static const GtkCssSelectorClass GTK_CSS_SELECTOR_CLASS = {
   "class",
   gtk_css_selector_class_print,
   gtk_css_selector_class_match,
   gtk_css_selector_class_tree_match,
   gtk_css_selector_class_get_change,
+  gtk_css_selector_class_compare_one,
   FALSE, TRUE, FALSE, TRUE, FALSE
 };
 
@@ -637,12 +714,21 @@ gtk_css_selector_id_get_change (const GtkCssSelector *selector)
   return gtk_css_selector_get_change (gtk_css_selector_previous (selector)) | GTK_CSS_CHANGE_ID;
 }
 
+
+static int
+gtk_css_selector_id_compare_one (const GtkCssSelector *a,
+				 const GtkCssSelector *b)
+{
+  return strcmp (a->data, b->data);
+}
+
 static const GtkCssSelectorClass GTK_CSS_SELECTOR_ID = {
   "id",
   gtk_css_selector_id_print,
   gtk_css_selector_id_match,
   gtk_css_selector_id_tree_match,
   gtk_css_selector_id_get_change,
+  gtk_css_selector_id_compare_one,
   TRUE, FALSE, FALSE, TRUE, FALSE
 };
 
@@ -714,12 +800,20 @@ gtk_css_selector_pseudoclass_state_get_change (const GtkCssSelector *selector)
   return gtk_css_selector_get_change (gtk_css_selector_previous (selector)) | GTK_CSS_CHANGE_STATE;
 }
 
+static int
+gtk_css_selector_pseudoclass_state_compare_one (const GtkCssSelector *a,
+						const GtkCssSelector *b)
+{
+  return GPOINTER_TO_UINT (a->data) - GPOINTER_TO_UINT (b->data);
+}
+
 static const GtkCssSelectorClass GTK_CSS_SELECTOR_PSEUDOCLASS_STATE = {
   "pseudoclass-state",
   gtk_css_selector_pseudoclass_state_print,
   gtk_css_selector_pseudoclass_state_match,
   gtk_css_selector_pseudoclass_state_tree_match,
   gtk_css_selector_pseudoclass_state_get_change,
+  gtk_css_selector_pseudoclass_state_compare_one,
   FALSE, TRUE, FALSE, TRUE, FALSE
 };
 
@@ -1057,12 +1151,20 @@ gtk_css_selector_pseudoclass_position_get_change (const GtkCssSelector *selector
   return gtk_css_selector_get_change (gtk_css_selector_previous (selector)) | GTK_CSS_CHANGE_POSITION;
 }
 
+static int
+gtk_css_selector_pseudoclass_position_compare_one (const GtkCssSelector *a,
+						   const GtkCssSelector *b)
+{
+  return GPOINTER_TO_UINT (a->data) - GPOINTER_TO_UINT (b->data);
+}
+
 static const GtkCssSelectorClass GTK_CSS_SELECTOR_PSEUDOCLASS_POSITION = {
   "pseudoclass-position",
   gtk_css_selector_pseudoclass_position_print,
   gtk_css_selector_pseudoclass_position_match,
   gtk_css_selector_pseudoclass_position_tree_match,
   gtk_css_selector_pseudoclass_position_get_change,
+  gtk_css_selector_pseudoclass_position_compare_one,
   FALSE, TRUE, FALSE, TRUE, TRUE
 };
 
@@ -1740,10 +1842,13 @@ subdivide_infos (GList *infos, GtkCssSelectorTree *parent)
   g_hash_table_iter_init (&iter, ht);
   while (g_hash_table_iter_next (&iter, &key, &value))
     {
-      if (GPOINTER_TO_UINT (value) > max_count)
+      GtkCssSelector *selector = key;
+      if (GPOINTER_TO_UINT (value) > max_count ||
+	  (GPOINTER_TO_UINT (value) == max_count &&
+	  gtk_css_selector_compare_one (selector, max_selector) < 0))
 	{
 	  max_count = GPOINTER_TO_UINT (value);
-	  max_selector = key;
+	  max_selector = selector;
 	}
     }