[rygel] server: Fix CSV splitting in ItemUpdater.

[Jens Georg <jensgeorg src gnome org>]

commit d4654c145d1ce7305f9ea20c5951cee908efe7a6
Author: Krzesimir Nowak <krnowak openismus com>
Date:   Tue Oct 30 09:04:02 2012 +0100

    server: Fix CSV splitting in ItemUpdater.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=687177

 src/librygel-server/rygel-item-updater.vala |   41 ++++++++++++++++++++++----
 1 files changed, 34 insertions(+), 7 deletions(-)
---
diff --git a/src/librygel-server/rygel-item-updater.vala b/src/librygel-server/rygel-item-updater.vala
index c7b460f..2af4f3f 100644
--- a/src/librygel-server/rygel-item-updater.vala
+++ b/src/librygel-server/rygel-item-updater.vala
@@ -27,6 +27,8 @@ using Gee;
  * UpdateObject action implementation.
  */
 internal class Rygel.ItemUpdater: GLib.Object, Rygel.StateMachine {
+    private static Regex escape_regex;
+
     private string object_id;
     private string current_tag_value;
     private string new_tag_value;
@@ -36,6 +38,14 @@ internal class Rygel.ItemUpdater: GLib.Object, Rygel.StateMachine {
 
     public Cancellable cancellable { get; set; }
 
+    static construct {
+        try {
+            escape_regex = new Regex ("\\\\(.)");
+        } catch (GLib.RegexError error) {
+            assert_not_reached ();
+        }
+    }
+
     public ItemUpdater (ContentDirectory    content_dir,
                         owned ServiceAction action) {
         this.content_dir = content_dir;
@@ -80,15 +90,29 @@ internal class Rygel.ItemUpdater: GLib.Object, Rygel.StateMachine {
         this.completed ();
     }
 
+    private static string unescape (string value) {
+        try {
+            return ItemUpdater.escape_regex.replace (value, -1, 0, "\\1");
+        } catch (GLib.RegexError error) {
+            return value;
+        }
+    }
+
     private static LinkedList<string> csv_split (string? tag_values) {
         var list = new LinkedList<string> ();
+
+        if (tag_values == null) {
+            return list;
+        }
+
         var escape = false;
         var token_start = 0;
         var token_length = 0;
-        var len = (tag_values != null ? tag_values.length : 0);
+        var len = tag_values.length;
 
         for (int iter = 0; iter < len; ++iter) {
             var c = tag_values[iter];
+            var increase = true;
 
             if (escape) {
                 escape = false;
@@ -99,20 +123,23 @@ internal class Rygel.ItemUpdater: GLib.Object, Rygel.StateMachine {
 
                     break;
                 case ',':
-                    list.add (tag_values.substring (token_start, token_length));
+                    var value = tag_values.substring (token_start,
+                                                      token_length);
+
+                    list.add (ItemUpdater.unescape (value));
                     token_start += token_length + 1;
                     token_length = 0;
+                    increase = false;
 
                     break;
                 }
             }
-            ++token_length;
+            if (increase) {
+                ++token_length;
+            }
         }
 
-        // Single tag value only
-        if (len > 0 && list.is_empty) {
-            list.add (tag_values);
-        }
+        list.add (ItemUpdater.unescape (tag_values.substring (token_start)));
 
         return list;
     }