From 74e3323db62156a84350c37298d3a2649e0293db Mon Sep 17 00:00:00 2001
From: Blottiere Paul <blottiere.paul@gmail.com>
Date: Tue, 14 Nov 2017 10:28:01 +0000
Subject: [PATCH] Never return a feature if the fid is negative

---
 src/providers/virtual/qgsvirtuallayerfeatureiterator.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/providers/virtual/qgsvirtuallayerfeatureiterator.cpp b/src/providers/virtual/qgsvirtuallayerfeatureiterator.cpp
index 1946d13473a0..f80f466f3464 100644
--- a/src/providers/virtual/qgsvirtuallayerfeatureiterator.cpp
+++ b/src/providers/virtual/qgsvirtuallayerfeatureiterator.cpp
@@ -110,7 +110,10 @@ QgsVirtualLayerFeatureIterator::QgsVirtualLayerFeatureIterator( QgsVirtualLayerF
     {
       if ( request.filterType() == QgsFeatureRequest::FilterFid )
       {
-        offset = QStringLiteral( " LIMIT 1 OFFSET %1" ).arg( request.filterFid() );
+        if ( request.filterFid() >= 0 )
+          offset = QStringLiteral( " LIMIT 1 OFFSET %1" ).arg( request.filterFid() );
+        else // never return a feature if the id is negative
+          offset = QStringLiteral( " LIMIT 0" );
       }
     }