metadata: don't crash if meta_tree_init fails

It can fail when e.g. database file is corrupted or doesn't have
correct permissions. This patch also adds warnings to be possible
determine reason why initialization failed.

It is based on patches from Matthew W. S. Bell and Ross Lagerwall.

https://bugzilla.gnome.org/show_bug.cgi?id=598561

2 files changed, 90 insertions, 67 deletions

diff --git a/client/gdaemonfile.c b/client/gdaemonfile.c
index e97c9a4e..53e5f9a0 100644
--- a/client/gdaemonfile.c
+++ b/client/gdaemonfile.c
@@ -830,12 +830,16 @@ add_metadata (GFile *file,
   tree = meta_tree_lookup_by_name (treename, FALSE);
   g_free (treename);
 
-  g_file_info_set_attribute_mask (info, matcher);
-  meta_tree_enumerate_keys (tree, daemon_file->path,
-			    enumerate_keys_callback, info);
-  g_file_info_unset_attribute_mask (info);
+  if (tree)
+    {
+      g_file_info_set_attribute_mask (info, matcher);
+      meta_tree_enumerate_keys (tree, daemon_file->path,
+                                enumerate_keys_callback, info);
+      g_file_info_unset_attribute_mask (info);
+
+      meta_tree_unref (tree);
+    }
 
-  meta_tree_unref (tree);
   g_file_attribute_matcher_unref (matcher);
 }
 
@@ -2649,6 +2653,14 @@ set_metadata_attribute (GFile *file,
   tree = meta_tree_lookup_by_name (treename, FALSE);
   g_free (treename);
   
+  if (!tree)
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   _("Error setting file metadata: %s"),
+                   _("can't open metadata tree"));
+      return FALSE;
+    }
+
   res = FALSE;
   proxy = _g_daemon_vfs_get_metadata_proxy (cancellable, error);
 
diff --git a/client/gdaemonvfs.c b/client/gdaemonvfs.c
index 9ab806b3..1060c440 100644
--- a/client/gdaemonvfs.c
+++ b/client/gdaemonvfs.c
@@ -1,3 +1,4 @@
+
 /* GIO - GLib Input, Output and Streaming Library
  * 
  * Copyright (C) 2006-2007 Red Hat, Inc.
@@ -1279,69 +1280,79 @@ g_daemon_vfs_local_file_set_attributes (GVfs       *vfs,
 						statbuf.st_dev,
 						FALSE,
 						&tree_path);
-	  
-	  proxy = _g_daemon_vfs_get_metadata_proxy (NULL, error);
-	  if (proxy == NULL)
-	    {
-	      res = FALSE;
+          if (!tree)
+            {
+              g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                           _("Error setting file metadata: %s"),
+                           _("can't open metadata tree"));
+              res = FALSE;
               error = NULL; /* Don't set further errors */
-	    }
-	  else
-	    {
-              builder = g_variant_builder_new (G_VARIANT_TYPE_VARDICT);
-	      metatreefile = meta_tree_get_filename (tree);
-              num_set = 0;
-
-              for (i = 0; attributes[i] != NULL; i++)
-                {
-                  if (g_file_info_get_attribute_data (info, attributes[i], &type, &value, NULL))
-                    {
-                      appended = _g_daemon_vfs_append_metadata_for_set (builder,
-                                                                        tree,
-                                                                        tree_path,
-                                                                        attributes[i],
-                                                                        type,
-                                                                        value);
-                      if (appended != -1)
-                        {
-                          num_set += appended;
-                          g_file_info_set_attribute_status (info, attributes[i],
-                                                            G_FILE_ATTRIBUTE_STATUS_SET);
-                        }
-                      else
-                        {
-                          res = FALSE;
-                          g_set_error (error, G_IO_ERROR,
-                                       G_IO_ERROR_INVALID_ARGUMENT,
-                                       _("Error setting file metadata: %s"),
-                                       _("values must be string or list of strings"));
-                          error = NULL; /* Don't set further errors */
-                          g_file_info_set_attribute_status (info, attributes[i],
-                                                            G_FILE_ATTRIBUTE_STATUS_ERROR_SETTING);
-                        }
-                    }
-                }
-	      
-	      if (num_set > 0 &&
-	          ! gvfs_metadata_call_set_sync (proxy,
-	                                         metatreefile,
-	                                         tree_path,
-	                                         g_variant_builder_end (builder),
-	                                         NULL,
-	                                         error))
-                {
-	          res = FALSE;
-                  error = NULL; /* Don't set further errors */
-                  for (i = 0; attributes[i] != NULL; i++)
-                    g_file_info_set_attribute_status (info, attributes[i],
-                                                      G_FILE_ATTRIBUTE_STATUS_ERROR_SETTING);
-                }
-
-	      g_variant_builder_unref (builder);
-	      
-              meta_lookup_cache_free (cache);
-              meta_tree_unref (tree);
-              g_free (tree_path);
+            }
+          else
+            {
+	      proxy = _g_daemon_vfs_get_metadata_proxy (NULL, error);
+	      if (proxy == NULL)
+		{
+		  res = FALSE;
+		  error = NULL; /* Don't set further errors */
+		}
+	      else
+		{
+		  builder = g_variant_builder_new (G_VARIANT_TYPE_VARDICT);
+		  metatreefile = meta_tree_get_filename (tree);
+		  num_set = 0;
+
+		  for (i = 0; attributes[i] != NULL; i++)
+		    {
+		      if (g_file_info_get_attribute_data (info, attributes[i], &type, &value, NULL))
+			{
+			  appended = _g_daemon_vfs_append_metadata_for_set (builder,
+									    tree,
+									    tree_path,
+									    attributes[i],
+									    type,
+									    value);
+			  if (appended != -1)
+			    {
+			      num_set += appended;
+			      g_file_info_set_attribute_status (info, attributes[i],
+								G_FILE_ATTRIBUTE_STATUS_SET);
+			    }
+			  else
+			    {
+			      res = FALSE;
+			      g_set_error (error, G_IO_ERROR,
+					   G_IO_ERROR_INVALID_ARGUMENT,
+					   _("Error setting file metadata: %s"),
+					   _("values must be string or list of strings"));
+			      error = NULL; /* Don't set further errors */
+			      g_file_info_set_attribute_status (info, attributes[i],
+								G_FILE_ATTRIBUTE_STATUS_ERROR_SETTING);
+			    }
+			}
+		    }
+
+		  if (num_set > 0 &&
+		      ! gvfs_metadata_call_set_sync (proxy,
+						     metatreefile,
+						     tree_path,
+						     g_variant_builder_end (builder),
+						     NULL,
+						     error))
+		    {
+		      res = FALSE;
+		      error = NULL; /* Don't set further errors */
+		      for (i = 0; attributes[i] != NULL; i++)
+			g_file_info_set_attribute_status (info, attributes[i],
+							  G_FILE_ATTRIBUTE_STATUS_ERROR_SETTING);
+		    }
+
+		  g_variant_builder_unref (builder);
+
+		  meta_lookup_cache_free (cache);
+		  meta_tree_unref (tree);
+		  g_free (tree_path);
+		}
 	    }
 	}