[tracker] tracker-extract: Improve checks for mimetype guessing

[Martyn James Russell <mr src gnome org>]

commit 4686a11268239aa402efd49df295f4502bf7eceb
Author: Martyn Russell <martyn lanedo com>
Date:   Wed Aug 3 16:11:21 2011 +0100

    tracker-extract: Improve checks for mimetype guessing
    
    Previously mimetype had to be NULL, but over dbus, it can only be an empty
    string. The check has been improved here.
    
    Additionally, we were leaking a GSimpleAsyncResult.
    
    There was also an issue with error conditions of the mimetype check where we
    would return and the client would be left hanging because we didn't complete
    the simple_async_result in that condition. That's now been fixed and any error
    reported by getting the mimetype also reported back to the client.

 src/tracker-extract/tracker-extract.c |   47 +++++++++++++++++++++------------
 1 files changed, 30 insertions(+), 17 deletions(-)
---
diff --git a/src/tracker-extract/tracker-extract.c b/src/tracker-extract/tracker-extract.c
index a5b403d..406ded6 100644
--- a/src/tracker-extract/tracker-extract.c
+++ b/src/tracker-extract/tracker-extract.c
@@ -395,30 +395,33 @@ extract_task_new (TrackerExtract *extract,
                   const gchar    *uri,
                   const gchar    *mimetype,
                   GCancellable   *cancellable,
-                  GAsyncResult   *res)
+                  GAsyncResult   *res,
+                  GError        **error)
 {
 	TrackerExtractTask *task;
 
-	if (!mimetype) {
+	if (!mimetype || !*mimetype) {
 		GFile *file;
 		GFileInfo *info;
+		GError *internal_error = NULL;
 
 		file = g_file_new_for_uri (uri);
 		info = g_file_query_info (file,
 		                          G_FILE_ATTRIBUTE_STANDARD_CONTENT_TYPE,
 		                          G_FILE_QUERY_INFO_NONE,
-		                          NULL, NULL);
+		                          NULL,
+		                          &internal_error);
 
-		if (info) {
-			mimetype = g_strdup (g_file_info_get_content_type (info));
-			g_debug ("Guessing mime type as '%s'", mimetype);
-			g_object_unref (info);
-		} else {
-			g_warning ("Could not get mimetype for '%s'", uri);
+		g_object_unref (file);
+
+		if (internal_error) {
+			g_propagate_error (error, internal_error);
 			return NULL;
 		}
 
-		g_object_unref (file);
+		mimetype = g_strdup (g_file_info_get_content_type (info));
+		g_debug ("Guessing mime type as '%s'", mimetype);
+		g_object_unref (info);
 	}
 
 	task = g_slice_new0 (TrackerExtractTask);
@@ -675,6 +678,7 @@ tracker_extract_file (TrackerExtract      *extract,
                       gpointer             user_data)
 {
 	GSimpleAsyncResult *res;
+	GError *error = NULL;
 	TrackerExtractTask *task;
 
 	g_return_if_fail (TRACKER_IS_EXTRACT (extract));
@@ -689,14 +693,19 @@ tracker_extract_file (TrackerExtract      *extract,
 
 	res = g_simple_async_result_new (G_OBJECT (extract), cb, user_data, NULL);
 
-	task = extract_task_new (extract, file, mimetype, cancellable, G_ASYNC_RESULT (res));
+	task = extract_task_new (extract, file, mimetype, cancellable, G_ASYNC_RESULT (res), &error);
 
-	if (task) {
+	if (error) {
+		g_warning ("Could not get mimetype, %s", error->message);
+		g_simple_async_result_set_from_error (res, error);
+		g_simple_async_result_complete_in_idle (res);
+		g_error_free (error);
+	} else {
 		g_idle_add ((GSourceFunc) dispatch_task_cb, task);
-
-		/* task takes a ref */
-		g_object_unref (res);
 	}
+
+	/* Task takes a ref and if this fails, we want to unref anyway */
+	g_object_unref (res);
 }
 
 static gboolean
@@ -748,6 +757,7 @@ tracker_extract_get_metadata_by_cmdline (TrackerExtract *object,
                                          const gchar    *mime)
 {
 	TrackerSparqlBuilder *statements, *preupdate;
+	GError *error = NULL;
 	gchar *where;
 	TrackerExtractPrivate *priv;
 	TrackerExtractTask *task;
@@ -758,9 +768,12 @@ tracker_extract_get_metadata_by_cmdline (TrackerExtract *object,
 
 	g_return_if_fail (uri != NULL);
 
-	task = extract_task_new (object, uri, mime, NULL, NULL);
+	task = extract_task_new (object, uri, mime, NULL, NULL, &error);
+
+	if (error) {
+		g_printerr ("Extraction failed, %s\n", error->message);
+		g_error_free (error);
 
-	if (!task) {
 		return;
 	}