css: Don't reorder some selectors when building selector tree

When building the tree we generally reorder the selectors inside
the same simple selector in order to pick a good first selector
to balance the tree better. However, some kinds of selectors
can't really be reordered, even thought they are simple.

This is since the matching code for some types handle
the existance of a directly preceeding selector differently:

 REGION and ANY selectors look for a DESCENDANT previous
 POSITION selector look for a REGION previous

1 files changed, 20 insertions, 15 deletions

diff --git a/gtk/gtkcssselector.c b/gtk/gtkcssselector.c
index 2197b1ea7e..6d767b2c0a 100644
--- a/gtk/gtkcssselector.c
+++ b/gtk/gtkcssselector.c
@@ -43,6 +43,7 @@ struct _GtkCssSelectorClass {
   guint         increase_class_specificity :1;
   guint         increase_element_specificity :1;
   guint         is_simple :1;
+  guint         must_keep_order :1; /* Due to region weirdness these must be kept before a DESCENDANT, so don't reorder */
 };
 
 struct _GtkCssSelector
@@ -187,7 +188,7 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_DESCENDANT = {
   gtk_css_selector_descendant_match,
   gtk_css_selector_descendant_tree_match,
   gtk_css_selector_descendant_get_change,
-  FALSE, FALSE, FALSE, FALSE
+  FALSE, FALSE, FALSE, FALSE, FALSE
 };
 
 /* CHILD */
@@ -238,7 +239,7 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_CHILD = {
   gtk_css_selector_child_match,
   gtk_css_selector_child_tree_match,
   gtk_css_selector_child_get_change,
-  FALSE, FALSE, FALSE, FALSE
+  FALSE, FALSE, FALSE, FALSE, FALSE
 };
 
 /* SIBLING */
@@ -301,7 +302,7 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_SIBLING = {
   gtk_css_selector_sibling_match,
   gtk_css_selector_sibling_tree_match,
   gtk_css_selector_sibling_get_change,
-  FALSE, FALSE, FALSE, FALSE
+  FALSE, FALSE, FALSE, FALSE, FALSE
 };
 
 /* ADJACENT */
@@ -354,7 +355,7 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_ADJACENT = {
   gtk_css_selector_adjacent_match,
   gtk_css_selector_adjacent_tree_match,
   gtk_css_selector_adjacent_get_change,
-  FALSE, FALSE, FALSE, FALSE
+  FALSE, FALSE, FALSE, FALSE, FALSE
 };
 
 /* ANY */
@@ -417,7 +418,7 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_ANY = {
   gtk_css_selector_any_match,
   gtk_css_selector_any_tree_match,
   gtk_css_selector_any_get_change,
-  FALSE, FALSE, FALSE, TRUE
+  FALSE, FALSE, FALSE, TRUE, TRUE
 };
 
 /* NAME */
@@ -468,7 +469,7 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_NAME = {
   gtk_css_selector_name_match,
   gtk_css_selector_name_tree_match,
   gtk_css_selector_name_get_change,
-  FALSE, FALSE, TRUE, TRUE
+  FALSE, FALSE, TRUE, TRUE, FALSE
 };
 
 /* REGION */
@@ -539,7 +540,7 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_REGION = {
   gtk_css_selector_region_match,
   gtk_css_selector_region_tree_match,
   gtk_css_selector_region_get_change,
-  FALSE, FALSE, TRUE, TRUE
+  FALSE, FALSE, TRUE, TRUE, TRUE
 };
 
 /* CLASS */
@@ -590,7 +591,7 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_CLASS = {
   gtk_css_selector_class_match,
   gtk_css_selector_class_tree_match,
   gtk_css_selector_class_get_change,
-  FALSE, TRUE, FALSE, TRUE
+  FALSE, TRUE, FALSE, TRUE, FALSE
 };
 
 /* ID */
@@ -641,7 +642,7 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_ID = {
   gtk_css_selector_id_match,
   gtk_css_selector_id_tree_match,
   gtk_css_selector_id_get_change,
-  TRUE, FALSE, FALSE, TRUE
+  TRUE, FALSE, FALSE, TRUE, FALSE
 };
 
 /* PSEUDOCLASS FOR STATE */
@@ -718,7 +719,7 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_PSEUDOCLASS_STATE = {
   gtk_css_selector_pseudoclass_state_match,
   gtk_css_selector_pseudoclass_state_tree_match,
   gtk_css_selector_pseudoclass_state_get_change,
-  FALSE, TRUE, FALSE, TRUE
+  FALSE, TRUE, FALSE, TRUE, FALSE
 };
 
 /* PSEUDOCLASS FOR POSITION */
@@ -1062,7 +1063,7 @@ static const GtkCssSelectorClass GTK_CSS_SELECTOR_PSEUDOCLASS_POSITION = {
   gtk_css_selector_pseudoclass_position_match,
   gtk_css_selector_pseudoclass_position_tree_match,
   gtk_css_selector_pseudoclass_position_get_change,
-  FALSE, TRUE, FALSE, TRUE
+  FALSE, TRUE, FALSE, TRUE, TRUE
 };
 
 /* API */
@@ -1525,14 +1526,16 @@ gtk_css_selectors_count_initial_init (void)
 static void
 gtk_css_selectors_count_initial (const GtkCssSelector *selector, GHashTable *hash)
 {
-  if (!selector->class->is_simple)
+  if (!selector->class->is_simple || selector->class->must_keep_order)
     {
       guint count = GPOINTER_TO_INT (g_hash_table_lookup (hash, selector));
       g_hash_table_replace (hash, (gpointer)selector, GUINT_TO_POINTER (count + 1));
       return;
     }
 
-  for (; selector && selector->class->is_simple; selector = gtk_css_selector_previous (selector))
+  for (;
+       selector && selector->class->is_simple && !selector->class->must_keep_order;
+       selector = gtk_css_selector_previous (selector))
     {
       guint count = GPOINTER_TO_INT (g_hash_table_lookup (hash, selector));
       g_hash_table_replace (hash, (gpointer)selector, GUINT_TO_POINTER (count + 1));
@@ -1542,10 +1545,12 @@ gtk_css_selectors_count_initial (const GtkCssSelector *selector, GHashTable *has
 static gboolean
 gtk_css_selectors_has_initial_selector (const GtkCssSelector *selector, const GtkCssSelector *initial)
 {
-  if (!selector->class->is_simple)
+  if (!selector->class->is_simple || selector->class->must_keep_order)
     return gtk_css_selector_equal (selector, initial);
 
-  for (; selector && selector->class->is_simple; selector = gtk_css_selector_previous (selector))
+  for (;
+       selector && selector->class->is_simple && !selector->class->must_keep_order;
+       selector = gtk_css_selector_previous (selector))
     {
       if (gtk_css_selector_equal (selector, initial))
 	return TRUE;