[glib: 1/2] GDesktopAppInfo: Try to always correctly set id

[Philip Withnall <pwithnall src gnome org>]

commit f065497acfbfe654369945054240918fcee001c3
Author: Ivaylo Dimitrov <ivo g dimitrov 75 gmail com>
Date:   Mon Dec 13 23:43:44 2021 +0200

    GDesktopAppInfo: Try to always correctly set id
    
    Specs say that on Unix id should be desktop file id from the xdg menu
    specification, however, currently code just uses basename of .desktop file.
    Fix that by finding the .desktop file in all the desktop_file_dirs and use
    basename only as a fallback.
    
    See https://specifications.freedesktop.org/menu-spec/latest/go01.html#term-desktop-file-id
    and https://specifications.freedesktop.org/desktop-entry-spec/latest/ar01s02.html#desktop-file-id
    
    "To determine the ID of a desktop file, make its full path relative to the
    $XDG_DATA_DIRS component in which the desktop file is installed, remove the
    "applications/" prefix, and turn '/' into '-'."
    
    Also, add unit test that verifies Desktop Id is being correctly set
    
    Signed-off-by: Ivaylo Dimitrov <ivo g dimitrov 75 gmail com>

 gio/gdesktopappinfo.c        | 96 +++++++++++++++++++++++++++++++++++++-------
 gio/tests/desktop-app-info.c | 13 ++++++
 2 files changed, 95 insertions(+), 14 deletions(-)
---
diff --git a/gio/gdesktopappinfo.c b/gio/gdesktopappinfo.c
index 55312fdfb..80f936ca1 100644
--- a/gio/gdesktopappinfo.c
+++ b/gio/gdesktopappinfo.c
@@ -89,6 +89,7 @@ enum {
 static void     g_desktop_app_info_iface_init         (GAppInfoIface    *iface);
 static gboolean g_desktop_app_info_ensure_saved       (GDesktopAppInfo  *info,
                                                        GError          **error);
+static gboolean g_desktop_app_info_load_file (GDesktopAppInfo *self);
 
 /**
  * GDesktopAppInfo:
@@ -1002,6 +1003,19 @@ desktop_file_dir_unindexed_init (DesktopFileDir *dir)
   desktop_file_dir_unindexed_read_mimeapps_lists (dir);
 }
 
+static GDesktopAppInfo *
+g_desktop_app_info_new_from_filename_unlocked (const char *filename)
+{
+  GDesktopAppInfo *info = NULL;
+
+  info = g_object_new (G_TYPE_DESKTOP_APP_INFO, "filename", filename, NULL);
+
+  if (!g_desktop_app_info_load_file (info))
+    g_clear_object (&info);
+
+  return info;
+}
+
 static GDesktopAppInfo *
 desktop_file_dir_unindexed_get_app (DesktopFileDir *dir,
                                     const gchar    *desktop_id)
@@ -1013,7 +1027,7 @@ desktop_file_dir_unindexed_get_app (DesktopFileDir *dir,
   if (!filename)
     return NULL;
 
-  return g_desktop_app_info_new_from_filename (filename);
+  return g_desktop_app_info_new_from_filename_unlocked (filename);
 }
 
 static void
@@ -1033,7 +1047,7 @@ desktop_file_dir_unindexed_get_all (DesktopFileDir *dir,
       if (desktop_file_dir_app_name_is_masked (dir, app_name))
         continue;
 
-      add_to_table_if_appropriate (apps, app_name, g_desktop_app_info_new_from_filename (filename));
+      add_to_table_if_appropriate (apps, app_name, g_desktop_app_info_new_from_filename_unlocked (filename));
     }
 }
 
@@ -1754,6 +1768,56 @@ binary_from_exec (const char *exec)
   return g_strndup (start, p - start);
 }
 
+/*< internal >
+ * g_desktop_app_info_get_desktop_id_for_filename
+ * @self: #GDesktopAppInfo to get desktop id of
+ *
+ * Tries to find the desktop ID for a particular `.desktop` filename, as per the
+ * [Desktop Entry Specification](https://specifications.freedesktop.org/desktop-
+ * entry-spec/desktop-entry-spec-latest.html#desktop-file-id).
+ *
+ * Returns: desktop id or basename if filename is unknown.
+ */
+static char *
+g_desktop_app_info_get_desktop_id_for_filename (GDesktopAppInfo *self)
+{
+  guint i;
+  gchar *desktop_id = NULL;
+
+  g_return_val_if_fail (self->filename != NULL, NULL);
+
+  for (i = 0; i < desktop_file_dirs->len; i++)
+    {
+      DesktopFileDir *dir = g_ptr_array_index (desktop_file_dirs, i);
+      GHashTable *app_names;
+      GHashTableIter iter;
+      gpointer key, value;
+
+      app_names = dir->app_names;
+
+      if (!app_names)
+        continue;
+
+      g_hash_table_iter_init (&iter, app_names);
+      while (g_hash_table_iter_next (&iter, &key, &value))
+        {
+          if (!strcmp (value, self->filename))
+            {
+              desktop_id = g_strdup (key);
+              break;
+            }
+        }
+
+      if (desktop_id)
+        break;
+    }
+
+  if (!desktop_id)
+    desktop_id = g_path_get_basename (self->filename);
+
+  return g_steal_pointer (&desktop_id);
+}
+
 static gboolean
 g_desktop_app_info_load_from_keyfile (GDesktopAppInfo *info,
                                       GKeyFile        *key_file)
@@ -1912,6 +1976,9 @@ g_desktop_app_info_load_from_keyfile (GDesktopAppInfo *info,
       g_free (basename);
     }
 
+  if (info->filename)
+    info->desktop_id = g_desktop_app_info_get_desktop_id_for_filename (info);
+
   info->keyfile = g_key_file_ref (key_file);
 
   return TRUE;
@@ -1925,8 +1992,6 @@ g_desktop_app_info_load_file (GDesktopAppInfo *self)
 
   g_return_val_if_fail (self->filename != NULL, FALSE);
 
-  self->desktop_id = g_path_get_basename (self->filename);
-
   key_file = g_key_file_new ();
 
   if (g_key_file_load_from_file (key_file, self->filename, G_KEY_FILE_NONE, NULL))
@@ -1953,11 +2018,14 @@ g_desktop_app_info_new_from_keyfile (GKeyFile *key_file)
 
   info = g_object_new (G_TYPE_DESKTOP_APP_INFO, NULL);
   info->filename = NULL;
+
+  desktop_file_dirs_lock ();
+
   if (!g_desktop_app_info_load_from_keyfile (info, key_file))
-    {
-      g_object_unref (info);
-      return NULL;
-    }
+    g_clear_object (&info);
+
+  desktop_file_dirs_unlock ();
+
   return info;
 }
 
@@ -1975,12 +2043,12 @@ g_desktop_app_info_new_from_filename (const char *filename)
 {
   GDesktopAppInfo *info = NULL;
 
-  info = g_object_new (G_TYPE_DESKTOP_APP_INFO, "filename", filename, NULL);
-  if (!g_desktop_app_info_load_file (info))
-    {
-      g_object_unref (info);
-      return NULL;
-    }
+  desktop_file_dirs_lock ();
+
+  info = g_desktop_app_info_new_from_filename_unlocked (filename);
+
+  desktop_file_dirs_unlock ();
+
   return info;
 }
 
diff --git a/gio/tests/desktop-app-info.c b/gio/tests/desktop-app-info.c
index 95a2a1589..4a5de6017 100644
--- a/gio/tests/desktop-app-info.c
+++ b/gio/tests/desktop-app-info.c
@@ -797,6 +797,18 @@ test_launch_as_manager (void)
   g_assert_finalize_object (context);
 }
 
+/* Test if Desktop-File Id is correctly formed */
+static void
+test_id (void)
+{
+  gchar *result;
+
+  result = run_apps ("default-for-type", "application/vnd.kde.okular-archive",
+                     TRUE, FALSE, NULL, NULL, NULL);
+  g_assert_cmpstr (result, ==, "kde4-okular.desktop\n");
+  g_free (result);
+}
+
 int
 main (int   argc,
       char *argv[])
@@ -818,6 +830,7 @@ main (int   argc,
   g_test_add_func ("/desktop-app-info/implements", test_implements);
   g_test_add_func ("/desktop-app-info/show-in", test_show_in);
   g_test_add_func ("/desktop-app-info/launch-as-manager", test_launch_as_manager);
+  g_test_add_func ("/desktop-app-info/id", test_id);
 
   return g_test_run ();
 }