From c869fa29b6d8ab5d6f47196743f23422fe40e30e Mon Sep 17 00:00:00 2001
From: rldhont <rldhont@gmail.com>
Date: Tue, 25 Apr 2017 18:03:28 +0200
Subject: [PATCH] [BUGFIX][Server] Filter restorer modifying layers and not
 well restoring them

The Subsetstring is updated through QgsVectorLayer::setSubsetString and restored by QgsVectorDataProvider::setSubsetString and it's not idempotent.
The solution is to use QgsVectorLayer::setSubsetString in the 2 cases.
---
 src/server/qgsfilterrestorer.cpp | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/server/qgsfilterrestorer.cpp b/src/server/qgsfilterrestorer.cpp
index 40bf9402573..ab399b202fc 100644
--- a/src/server/qgsfilterrestorer.cpp
+++ b/src/server/qgsfilterrestorer.cpp
@@ -61,10 +61,9 @@ void QgsOWSServerFilterRestorer::restoreLayerFilters( const QHash<QgsMapLayer *,
     QgsVectorLayer *filteredLayer = qobject_cast<QgsVectorLayer *>( filterIt.key() );
     if ( filteredLayer )
     {
-      QgsVectorDataProvider *dp = filteredLayer->dataProvider();
-      if ( dp )
+      if ( !filteredLayer->setSubsetString( filterIt.value() ) )
       {
-        dp->setSubsetString( filterIt.value() );
+        QgsMessageLog::logMessage( QStringLiteral( "Layer does not support Subset String" ) );
       }
     }
   }