cssprovider: Keep track of passed in error differently

Instead of having an error member in the CSS provider's private struct,
connect a signal handler when an error is passed in. This has two
advantages:
1) It makes the code clearer as we don't have to keep track of an error
   member anywhere.
2) It causes a non-emission of the g_warning() when an error was passed
   in, because it only triggers when no signal handlers are connected.
   So we get identical behavior to GTK 3.0 where warnings where only
   emitted when no error was passed in.

diff --git a/gtk/gtkcssprovider.c b/gtk/gtkcssprovider.c
index c121bed7ea61b64b35ec3d3c82379a1ab25365bc..fda123b7accc1b8470bb4fcd23b75c8ef25598e8 100644 (file)
--- a/gtk/gtkcssprovider.c
+++ b/gtk/gtkcssprovider.c
@@ -800,9 +800,6 @@ struct _GtkCssProviderPrivate
   GHashTable *symbolic_colors;
 
   GPtrArray *selectors_info;
-
-  /* Current parser state */
-  GError *error;
 };
 
 enum ParserScope {
@@ -869,14 +866,6 @@ gtk_css_provider_parsing_error (GtkCssProvider  *provider,
                                 guint            position,
                                 const GError *   error)
 {
-  GtkCssProviderPrivate *priv = provider->priv;
-
-  if (!priv->error)
-    {
-      priv->error = g_error_copy (error);
-      g_prefix_error (&priv->error, "%s:%u:%u: ", path ? path : "<unknown>", line, position);
-    }
-
   /* Only emit a warning when we have no error handlers. This is our
    * default handlers. And in this case erroneous CSS files are a bug
    * and should be fixed.
@@ -1774,10 +1763,6 @@ css_provider_reset_parser (GtkCssProvider *css_provider)
   priv = css_provider->priv;
 
   gtk_css_scanner_reset (priv->scanner);
-
-  if (priv->error)
-    g_error_free (priv->error);
-  priv->error = NULL;
 }
 
 static void
@@ -2599,18 +2584,37 @@ gtk_css_provider_reset (GtkCssProvider *css_provider)
     g_ptr_array_remove_range (priv->selectors_info, 0, priv->selectors_info->len);
 }
 
+static void
+gtk_css_provider_propagate_error (GtkCssProvider  *provider,
+                                  const gchar     *path,
+                                  guint            line,
+                                  guint            position,
+                                  const GError    *error,
+                                  GError         **propagate_to)
+{
+  /* we already set an error. And we'd like to keep the first one */
+  if (*propagate_to)
+    return;
+
+  *propagate_to = g_error_copy (error);
+  g_prefix_error (propagate_to, "%s:%u:%u: ", path ? path : "<unknown>", line, position);
+}
 
 static gboolean
 parse_stylesheet (GtkCssProvider  *css_provider,
                   GScanner        *scanner,
                   GError         **error)
 {
-  GtkCssProviderPrivate *priv;
-  gboolean result;
+  gulong error_handler;
 
-  result = TRUE;
+  if (error)
+    error_handler = g_signal_connect (css_provider,
+                                      "parsing-error",
+                                      G_CALLBACK (gtk_css_provider_propagate_error),
+                                      error);
+  else
+    error_handler = 0; /* silence gcc */
 
-  priv = css_provider->priv;
   g_scanner_get_next_token (scanner);
 
   while (!g_scanner_eof (scanner))
@@ -2634,7 +2638,19 @@ parse_stylesheet (GtkCssProvider  *css_provider,
       g_scanner_get_next_token (scanner);
     }
 
-  return result;
+  if (error)
+    {
+      g_signal_handler_disconnect (css_provider, error_handler);
+      
+      if (*error)
+        {
+          /* We clear all contents from the provider for backwards compat reasons */
+          gtk_css_provider_reset (css_provider);
+          return FALSE;
+        }
+    }
+
+  return TRUE;
 }
 
 /**