From 3ce5275800b11cf7b7f6cd9e45fac8f6c661d5a9 Mon Sep 17 00:00:00 2001
From: Hugo Mercier <hugo.mercier@oslandia.com>
Date: Mon, 5 Jan 2015 12:04:15 +0100
Subject: [PATCH] Test for write access mode for editing capabilities

---
 src/providers/ogr/qgsogrprovider.cpp | 17 +++++++++++------
 src/providers/ogr/qgsogrprovider.h   |  3 +++
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/providers/ogr/qgsogrprovider.cpp b/src/providers/ogr/qgsogrprovider.cpp
index 05341657777..5c13eb8f53e 100644
--- a/src/providers/ogr/qgsogrprovider.cpp
+++ b/src/providers/ogr/qgsogrprovider.cpp
@@ -268,6 +268,7 @@ QgsOgrProvider::QgsOgrProvider( QString const & uri )
     , valid( false )
     , featuresCounted( -1 )
     , mDataModified( false )
+    , mWriteAccess( false )
 {
   QgsCPLErrorHandler handler;
 
@@ -368,7 +369,11 @@ QgsOgrProvider::QgsOgrProvider( QString const & uri )
   if ( !openReadOnly )
     ogrDataSource = OGROpen( TO8F( mFilePath ), true, &ogrDriver );
 
-  if ( !ogrDataSource )
+  if ( ogrDataSource )
+  {
+    mWriteAccess = true;
+  }
+  else
   {
     QgsDebugMsg( "OGR failed to opened in update mode, trying in read-only mode" );
 
@@ -1442,19 +1447,19 @@ int QgsOgrProvider::capabilities() const
       ability |= QgsVectorDataProvider::SelectAtId | QgsVectorDataProvider::SelectGeometryAtId;
     }
 
-    if ( OGR_L_TestCapability( ogrLayer, "SequentialWrite" ) )
+    if ( mWriteAccess && OGR_L_TestCapability( ogrLayer, "SequentialWrite" ) )
       // true if the CreateFeature() method works for this layer.
     {
       ability |= QgsVectorDataProvider::AddFeatures;
     }
 
-    if ( OGR_L_TestCapability( ogrLayer, "DeleteFeature" ) )
+    if ( mWriteAccess && OGR_L_TestCapability( ogrLayer, "DeleteFeature" ) )
       // true if this layer can delete its features
     {
       ability |= DeleteFeatures;
     }
 
-    if ( OGR_L_TestCapability( ogrLayer, "RandomWrite" ) )
+    if ( mWriteAccess && OGR_L_TestCapability( ogrLayer, "RandomWrite" ) )
       // true if the SetFeature() method is operational on this layer.
     {
       // TODO According to http://shapelib.maptools.org/ (Shapefile C Library V1.2)
@@ -1502,12 +1507,12 @@ int QgsOgrProvider::capabilities() const
     }
 #endif
 
-    if ( OGR_L_TestCapability( ogrLayer, "CreateField" ) )
+    if ( mWriteAccess && OGR_L_TestCapability( ogrLayer, "CreateField" ) )
     {
       ability |= AddAttributes;
     }
 
-    if ( OGR_L_TestCapability( ogrLayer, "DeleteField" ) )
+    if ( mWriteAccess && OGR_L_TestCapability( ogrLayer, "DeleteField" ) )
     {
       ability |= DeleteAttributes;
     }
diff --git a/src/providers/ogr/qgsogrprovider.h b/src/providers/ogr/qgsogrprovider.h
index bd4da19692e..56a0c4bfba9 100644
--- a/src/providers/ogr/qgsogrprovider.h
+++ b/src/providers/ogr/qgsogrprovider.h
@@ -344,6 +344,9 @@ class QgsOgrProvider : public QgsVectorDataProvider
     OGRLayerH setSubsetString( OGRLayerH layer, OGRDataSourceH ds );
 
     friend class QgsOgrFeatureSource;
+
+    /** whether the file is opened in write mode*/
+    bool mWriteAccess;
 };