[gtk+] Handle match_all returning NULL

[Matthias Clasen <matthiasc src gnome org>]

commit 2d29ae4159a084262e3aefd79d61987476e54a91
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Sep 9 10:55:31 2015 -0400

    Handle match_all returning NULL
    
    This is in preparation for not allocating an array at all if there
    are no matches.

 gtk/gtkcssprovider.c |  132 ++++++++++++++++++++++++++------------------------
 1 files changed, 69 insertions(+), 63 deletions(-)
---
diff --git a/gtk/gtkcssprovider.c b/gtk/gtkcssprovider.c
index 66e7d85..18a2c9c 100644
--- a/gtk/gtkcssprovider.c
+++ b/gtk/gtkcssprovider.c
@@ -1638,15 +1638,20 @@ verify_tree_get_change_results (GtkCssProvider *provider,
     int i;
 
     tree_rules = _gtk_css_selector_tree_match_all (provider->priv->tree, matcher);
-    verify_tree_match_results (provider, matcher, tree_rules);
-
-    for (i = tree_rules->len - 1; i >= 0; i--)
+    if (tree_rules)
       {
-       GtkCssRuleset *ruleset;
+        verify_tree_match_results (provider, matcher, tree_rules);
+
+        for (i = tree_rules->len - 1; i >= 0; i--)
+          {
+           GtkCssRuleset *ruleset;
 
-       ruleset = tree_rules->pdata[i];
+            ruleset = tree_rules->pdata[i];
+
+            verify_change |= _gtk_css_selector_get_change (ruleset->selector);
+          }
 
-       verify_change |= _gtk_css_selector_get_change (ruleset->selector);
+        g_ptr_array_free (tree_rules, TRUE);
       }
 
     if (change != verify_change)
@@ -1671,8 +1676,6 @@ verify_tree_get_change_results (GtkCssProvider *provider,
        g_warning (s->str);
        g_string_free (s, TRUE);
       }
-
-    g_ptr_array_free (tree_rules, TRUE);
   }
 #endif
 }
@@ -1711,46 +1714,46 @@ gtk_css_provider_get_style_property (GtkStyleProvider *provider,
     }
 
   tree_rules = _gtk_css_selector_tree_match_all (priv->tree, &matcher);
-  verify_tree_match_results (css_provider, &matcher, tree_rules);
-
-  prop_name = g_strdup_printf ("-%s-%s",
-                               g_type_name (pspec->owner_type),
-                               pspec->name);
-
-  for (i = tree_rules->len - 1; i >= 0; i--)
+  if (tree_rules)
     {
-      GtkCssRuleset *ruleset = tree_rules->pdata[i];
+      verify_tree_match_results (css_provider, &matcher, tree_rules);
 
-      if (ruleset->widget_style == NULL)
-        continue;
+      prop_name = g_strdup_printf ("-%s-%s",
+                                   g_type_name (pspec->owner_type),
+                                   pspec->name);
 
-      for (val = ruleset->widget_style; val != NULL; val = val->next)
-       {
-         if (strcmp (val->name, prop_name) == 0)
-           {
-             GtkCssScanner *scanner;
-
-             scanner = gtk_css_scanner_new (css_provider,
-                                            NULL,
-                                            val->section,
-                                            val->section != NULL ? gtk_css_section_get_file (val->section) : 
NULL,
-                                            val->value);
+      for (i = tree_rules->len - 1; i >= 0; i--)
+        {
+          GtkCssRuleset *ruleset = tree_rules->pdata[i];
 
-             found = _gtk_css_style_funcs_parse_value (value,
-                                                       scanner->parser);
+          if (ruleset->widget_style == NULL)
+            continue;
 
-             gtk_css_scanner_destroy (scanner);
+          for (val = ruleset->widget_style; val != NULL; val = val->next)
+            {
+              if (strcmp (val->name, prop_name) == 0)
+                {
+                  GtkCssScanner *scanner;
+
+                 scanner = gtk_css_scanner_new (css_provider,
+                                                 NULL,
+                                                 val->section,
+                                                 val->section != NULL ? gtk_css_section_get_file 
(val->section) : NULL,
+                                                 val->value);
+                  found = _gtk_css_style_funcs_parse_value (value, scanner->parser);
+                  gtk_css_scanner_destroy (scanner);
+                 break;
+                }
+            }
 
-             break;
-           }
-       }
+          if (found)
+            break;
+        }
 
-      if (found)
-       break;
+      g_free (prop_name);
+      g_ptr_array_free (tree_rules, TRUE);
     }
 
-  g_free (prop_name);
-  g_ptr_array_free (tree_rules, TRUE);
   gtk_widget_path_unref (path);
 
   return found;
@@ -1797,39 +1800,42 @@ gtk_css_style_provider_lookup (GtkStyleProviderPrivate *provider,
   priv = css_provider->priv;
 
   tree_rules = _gtk_css_selector_tree_match_all (priv->tree, matcher);
-  verify_tree_match_results (css_provider, matcher, tree_rules);
-
-  for (i = tree_rules->len - 1; i >= 0; i--)
+  if (tree_rules)
     {
-      ruleset = tree_rules->pdata[i];
+      verify_tree_match_results (css_provider, matcher, tree_rules);
 
-      if (ruleset->styles == NULL)
-        continue;
-
-      if (!_gtk_bitmask_intersects (_gtk_css_lookup_get_missing (lookup),
-                                    ruleset->set_styles))
-        continue;
-
-      for (j = 0; j < ruleset->n_styles; j++)
+      for (i = tree_rules->len - 1; i >= 0; i--)
         {
-          GtkCssStyleProperty *prop = ruleset->styles[j].property;
-          guint id = _gtk_css_style_property_get_id (prop);
+          ruleset = tree_rules->pdata[i];
 
-          if (!_gtk_css_lookup_is_missing (lookup, id))
+          if (ruleset->styles == NULL)
             continue;
 
-          _gtk_css_lookup_set (lookup,
-                               id,
-                               ruleset->styles[j].section,
-                               ruleset->styles[j].value);
+          if (!_gtk_bitmask_intersects (_gtk_css_lookup_get_missing (lookup),
+                                        ruleset->set_styles))
+          continue;
+
+          for (j = 0; j < ruleset->n_styles; j++)
+            {
+              GtkCssStyleProperty *prop = ruleset->styles[j].property;
+              guint id = _gtk_css_style_property_get_id (prop);
+
+              if (!_gtk_css_lookup_is_missing (lookup, id))
+                continue;
+
+              _gtk_css_lookup_set (lookup,
+                                   id,
+                                   ruleset->styles[j].section,
+                                  ruleset->styles[j].value);
+            }
+
+          if (_gtk_bitmask_is_empty (_gtk_css_lookup_get_missing (lookup)))
+            break;
         }
 
-      if (_gtk_bitmask_is_empty (_gtk_css_lookup_get_missing (lookup)))
-        break;
+      g_ptr_array_free (tree_rules, TRUE);
     }
 
-  g_ptr_array_free (tree_rules, TRUE);
-
   if (change)
     {
       GtkCssMatcher change_matcher;