[rygel] media-export: Use derivedFrom on class

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit fbc7f042872b74be4450a396be0d24765932a972
Author: Jens Georg <mail jensge org>
Date:   Sat Aug 14 11:31:00 2010 +0300

    media-export: Use derivedFrom on class
    
    If a virtual folder contains a match on upnp:class, assume that the
    derivedFrom operator is meant

 .../rygel-media-export-query-container.vala        |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/src/plugins/media-export/rygel-media-export-query-container.vala b/src/plugins/media-export/rygel-media-export-query-container.vala
index 607f396..a0c5281 100644
--- a/src/plugins/media-export/rygel-media-export-query-container.vala
+++ b/src/plugins/media-export/rygel-media-export-query-container.vala
@@ -245,7 +245,11 @@ internal class Rygel.MediaExport.QueryContainer : DBContainer {
         var exp = new RelationalExpression ();
         var op1 = op1_.replace (PREFIX, "");
         exp.operand1 = Uri.unescape_string (op1);
-        exp.op = SearchCriteriaOp.EQ;
+        if (exp.operand1 == "upnp:class") {
+            exp.op = SearchCriteriaOp.DERIVED_FROM;
+        } else {
+            exp.op = SearchCriteriaOp.EQ;
+        }
         exp.operand2 = Uri.unescape_string (op2);
         if (this.expression != null) {
             var exp2 = new LogicalExpression ();