[gtk+] cssprovider: Have a section on import error

[Benjamin Otte <otte src gnome org>]

commit 0a4e88b79b9fa20ae0bd61ff68e99abeb5753da3
Author: Benjamin Otte <otte redhat com>
Date:   Mon Nov 16 17:36:50 2015 +0100

    cssprovider: Have a section on import error
    
    When loading a nonexisting CSS file using
    gtk_css_provider_load_from_file() or gtk_css_provider_load_from_path()
    we would emit the error using a NULL scanner. Don't do that, because
    we'll have a NULL section in that case and error handlers don't like
    that.
    
    Testcase attached.
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1277959

 gtk/gtkcssprovider.c        |   22 ++++++++++++++--------
 testsuite/gtk/cssprovider.c |   13 +++++++++++++
 2 files changed, 27 insertions(+), 8 deletions(-)
---
diff --git a/gtk/gtkcssprovider.c b/gtk/gtkcssprovider.c
index 50108c3..fbe9163 100644
--- a/gtk/gtkcssprovider.c
+++ b/gtk/gtkcssprovider.c
@@ -1943,6 +1943,9 @@ gtk_css_provider_error (GtkCssProvider *provider,
   GError *error;
   va_list args;
 
+  gtk_internal_return_if_fail (GTK_IS_CSS_PROVIDER (provider));
+  gtk_internal_return_if_fail (scanner != NULL);
+
   va_start (args, format);
   error = g_error_new_valist (domain, code, format, args);
   va_end (args);
@@ -2725,21 +2728,24 @@ gtk_css_provider_load_internal (GtkCssProvider *css_provider,
         }
       else
         {
-          GtkCssSection *section;
-          
-          if (parent)
-            section = gtk_css_section_ref (parent->section);
-          else
-            section = _gtk_css_section_new_for_file (GTK_CSS_SECTION_DOCUMENT, file);
+          scanner = gtk_css_scanner_new (css_provider,
+                                         parent,
+                                         parent ? parent->section : NULL,
+                                         file,
+                                         "");
+
+          gtk_css_scanner_push_section (scanner, GTK_CSS_SECTION_DOCUMENT);
 
           gtk_css_provider_error (css_provider,
-                                  parent,
+                                  scanner,
                                   GTK_CSS_PROVIDER_ERROR,
                                   GTK_CSS_PROVIDER_ERROR_IMPORT,
                                   "Failed to import: %s",
                                   load_error->message);
 
-          gtk_css_section_unref (section);
+          gtk_css_scanner_pop_section (scanner, GTK_CSS_SECTION_DOCUMENT);
+
+          gtk_css_scanner_destroy (scanner);
         }
     }
 
diff --git a/testsuite/gtk/cssprovider.c b/testsuite/gtk/cssprovider.c
index 5222620..413c750 100644
--- a/testsuite/gtk/cssprovider.c
+++ b/testsuite/gtk/cssprovider.c
@@ -50,6 +50,18 @@ G_GNUC_END_IGNORE_DEPRECATIONS;
   g_object_unref (provider);
 }
 
+static void
+test_section_load_nonexisting_file (void)
+{
+  GtkCssProvider *provider;
+
+  provider = gtk_css_provider_new ();
+  g_signal_connect (provider, "parsing-error",
+                    G_CALLBACK (assert_section_is_not_null), NULL);
+  gtk_css_provider_load_from_path (provider, "this/path/does/absolutely/not/exist.css", NULL);
+  g_object_unref (provider);
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -58,6 +70,7 @@ main (int argc, char *argv[])
 
   g_test_add_func ("/cssprovider/section-in-load-from-data", test_section_in_load_from_data);
   g_test_add_func ("/cssprovider/section-in-style-property", test_section_in_style_property);
+  g_test_add_func ("/cssprovider/load-nonexisting-file", test_section_load_nonexisting_file);
 
   return g_test_run ();
 }