[nautilus/gnome-3-6] shell-provider: make the provider more robust to cancellation

[Cosimo Cecchi <cosimoc src gnome org>]

commit 94971592e200274da9d6c910aff75e77c10d8415
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Thu Oct 18 17:17:47 2012 -0400

    shell-provider: make the provider more robust to cancellation
    
    Don't assume there's only one engine running at the time, and avoid
    requiring state from the global app singleton in search callbacks.
    
    This fixes a crash where we would dereference NULL in the hits-added
    callback, since we would access it through the global app object, and
    self->active_search was previously cleared on cancellation.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=686168

 src/nautilus-shell-search-provider.c |   81 ++++++++++++++++------------------
 1 files changed, 38 insertions(+), 43 deletions(-)
---
diff --git a/src/nautilus-shell-search-provider.c b/src/nautilus-shell-search-provider.c
index c8f0263..55f795e 100644
--- a/src/nautilus-shell-search-provider.c
+++ b/src/nautilus-shell-search-provider.c
@@ -40,7 +40,12 @@
 
 #define SEARCH_PROVIDER_INACTIVITY_TIMEOUT 12000 /* milliseconds */
 
+typedef GApplicationClass NautilusShellSearchProviderAppClass;
+typedef struct _NautilusShellSearchProviderApp NautilusShellSearchProviderApp;
+
 typedef struct {
+  NautilusShellSearchProviderApp *self;
+
   NautilusSearchEngine *engine;
   NautilusQuery *query;
 
@@ -50,7 +55,7 @@ typedef struct {
   gint64 start_time;
 } PendingSearch;
 
-typedef struct {
+struct _NautilusShellSearchProviderApp {
   GApplication parent;
 
   guint name_owner_id;
@@ -63,9 +68,7 @@ typedef struct {
 
   NautilusBookmarkList *bookmarks;
   GVolumeMonitor *volumes;
-} NautilusShellSearchProviderApp;
-
-typedef GApplicationClass NautilusShellSearchProviderAppClass;
+};
 
 GType nautilus_shell_search_provider_app_get_type (void);
 
@@ -142,30 +145,24 @@ pending_search_free (PendingSearch *search)
 }
 
 static void
-finish_current_search (NautilusShellSearchProviderApp *self,
-                       GDBusMethodInvocation          *invocation,
-                       GVariant                       *result)
+pending_search_finish (PendingSearch         *search,
+                       GDBusMethodInvocation *invocation,
+                       GVariant              *result)
 {
-  g_dbus_method_invocation_return_value (invocation, result);
-
-  if (self->current_search != NULL) {
-    g_application_release (G_APPLICATION (self));
+  NautilusShellSearchProviderApp *self = search->self;
 
-    pending_search_free (self->current_search);
+  if (search == self->current_search)
     self->current_search = NULL;
-  }
+
+  g_application_release (G_APPLICATION (self));
+  pending_search_free (search);
 }
 
 static void
 cancel_current_search (NautilusShellSearchProviderApp *self)
 {
-  PendingSearch *search = self->current_search;
-
-  if (search == NULL)
-    return;
-
-  nautilus_search_provider_stop (NAUTILUS_SEARCH_PROVIDER (search->engine));
-  finish_current_search (self, search->invocation, g_variant_new ("(as)", NULL));
+  if (self->current_search != NULL)
+    nautilus_search_provider_stop (NAUTILUS_SEARCH_PROVIDER (self->current_search->engine));
 }
 
 static void
@@ -174,8 +171,7 @@ search_hits_added_cb (NautilusSearchEngine *engine,
                       gpointer              user_data)
 
 {
-  NautilusShellSearchProviderApp *self = user_data;
-  PendingSearch *search = self->current_search;
+  PendingSearch *search = user_data;
   GList *l;
   NautilusSearchHit *hit;
   const gchar *hit_uri;
@@ -217,8 +213,7 @@ static void
 search_finished_cb (NautilusSearchEngine *engine,
                     gpointer              user_data)
 {
-  NautilusShellSearchProviderApp *self = user_data;
-  PendingSearch *search = self->current_search;
+  PendingSearch *search = user_data;
   GList *hits, *l;
   NautilusSearchHit *hit;
   GVariantBuilder builder;
@@ -239,7 +234,7 @@ search_finished_cb (NautilusSearchEngine *engine,
   }
 
   g_list_free (hits);
-  finish_current_search (self, search->invocation,
+  pending_search_finish (search, search->invocation,
                          g_variant_new ("(as)", &builder));
 }
 
@@ -252,7 +247,8 @@ search_error_cb (NautilusSearchEngine *engine,
   PendingSearch *search = self->current_search;
 
   g_debug ("*** Search engine search error");
-  finish_current_search (self, search->invocation, g_variant_new ("(as)", NULL));
+  pending_search_finish (search, search->invocation,
+                         g_variant_new ("(as)", NULL));
 }
 
 typedef struct {
@@ -282,7 +278,7 @@ search_hit_candidate_new (const gchar *uri,
 }
 
 static void
-search_add_volumes_and_bookmarks (NautilusShellSearchProviderApp *self)
+search_add_volumes_and_bookmarks (PendingSearch *search)
 {
   NautilusSearchHit *hit;
   NautilusBookmark *bookmark;
@@ -300,9 +296,9 @@ search_add_volumes_and_bookmarks (NautilusShellSearchProviderApp *self)
   candidates = NULL;
 
   /* first add bookmarks */
-  length = nautilus_bookmark_list_length (self->bookmarks);
+  length = nautilus_bookmark_list_length (search->self->bookmarks);
   for (idx = 0; idx < length; idx++) {
-    bookmark = nautilus_bookmark_list_item_at (self->bookmarks, idx);
+    bookmark = nautilus_bookmark_list_item_at (search->self->bookmarks, idx);
 
     name = nautilus_bookmark_get_name (bookmark);
     if (name == NULL)
@@ -329,7 +325,7 @@ search_add_volumes_and_bookmarks (NautilusShellSearchProviderApp *self)
   mounts_to_check = NULL;
 
   /* first check all connected drives */
-  drives = g_volume_monitor_get_connected_drives (self->volumes);
+  drives = g_volume_monitor_get_connected_drives (search->self->volumes);
   for (l = drives; l != NULL; l = l->next) {
     drive = l->data;
     volumes = g_drive_get_volumes (drive);
@@ -347,7 +343,7 @@ search_add_volumes_and_bookmarks (NautilusShellSearchProviderApp *self)
   g_list_free_full (drives, g_object_unref);
 
   /* then volumes that don't have a drive */
-  volumes = g_volume_monitor_get_volumes (self->volumes);
+  volumes = g_volume_monitor_get_volumes (search->self->volumes);
   for (l = volumes; l != NULL; l = l->next) {
     volume = l->data;
     drive = g_volume_get_drive (volume);
@@ -363,7 +359,7 @@ search_add_volumes_and_bookmarks (NautilusShellSearchProviderApp *self)
   g_list_free_full (volumes, g_object_unref);
 
   /* then mounts that have no volume */
-  mounts = g_volume_monitor_get_mounts (self->volumes);
+  mounts = g_volume_monitor_get_mounts (search->self->volumes);
   for (l = mounts; l != NULL; l = l->next) {
     mount = l->data;
 
@@ -401,14 +397,14 @@ search_add_volumes_and_bookmarks (NautilusShellSearchProviderApp *self)
 
   for (l = candidates; l != NULL; l = l->next) {
     candidate = l->data;
-    match = nautilus_query_matches_string (self->current_search->query,
+    match = nautilus_query_matches_string (search->query,
                                            candidate->string_for_compare);
 
     if (match > -1) {
       hit = nautilus_search_hit_new (candidate->uri);
       nautilus_search_hit_set_fts_rank (hit, match);
-      nautilus_search_hit_compute_scores (hit, self->current_search->query);
-      g_hash_table_replace (self->current_search->hits, g_strdup (candidate->uri), hit);
+      nautilus_search_hit_compute_scores (hit, search->query);
+      g_hash_table_replace (search->hits, g_strdup (candidate->uri), hit);
     }
   }
   g_list_free_full (candidates, (GDestroyNotify) search_hit_candidate_free);
@@ -423,14 +419,12 @@ execute_search (NautilusShellSearchProviderApp *self,
   NautilusQuery *query;
   PendingSearch *pending_search;
 
-  if (self->current_search != NULL)
-    cancel_current_search (self);
+  cancel_current_search (self);
 
   /* don't attempt searches for a single character */
   if (g_strv_length (terms) == 1 &&
       g_utf8_strlen (terms[0], -1) == 1) {
-    finish_current_search (self, invocation,
-                           g_variant_new ("(as)", NULL));
+    g_dbus_method_invocation_return_value (invocation, g_variant_new ("(as)", NULL));
     return;
   }
 
@@ -448,18 +442,19 @@ execute_search (NautilusShellSearchProviderApp *self,
   pending_search->query = query;
   pending_search->engine = nautilus_search_engine_new ();
   pending_search->start_time = g_get_monotonic_time ();
+  pending_search->self = self;
 
   g_signal_connect (pending_search->engine, "hits-added",
-                    G_CALLBACK (search_hits_added_cb), self);
+                    G_CALLBACK (search_hits_added_cb), pending_search);
   g_signal_connect (pending_search->engine, "finished",
-                    G_CALLBACK (search_finished_cb), self);
+                    G_CALLBACK (search_finished_cb), pending_search);
   g_signal_connect (pending_search->engine, "error",
-                    G_CALLBACK (search_error_cb), self);
+                    G_CALLBACK (search_error_cb), pending_search);
 
   self->current_search = pending_search;
   g_application_hold (G_APPLICATION (self));
 
-  search_add_volumes_and_bookmarks (self);
+  search_add_volumes_and_bookmarks (pending_search);
 
   /* start searching */
   g_debug ("*** Search engine search started");