Fix crash with invalid postgres provider

Crash is triggered by opening the postgres vector layer properties with a not-yet-known CRS.
qgis · Oct 30, 2019 · 95fb8e6 · 95fb8e6
1 parent 28bd757
commit 95fb8e6
Showing 1 changed file with 7 additions and 4 deletions.
diff --git a/src/providers/postgres/qgspostgresprovider.cpp b/src/providers/postgres/qgspostgresprovider.cpp
@@ -4272,11 +4272,14 @@ QgsCoordinateReferenceSystem QgsPostgresProvider::crs() const
     else
     {
       QgsPostgresConn *conn = connectionRO();
-      QgsPostgresResult result( conn->PQexec( QStringLiteral( "SELECT proj4text FROM spatial_ref_sys WHERE srid=%1" ).arg( srid ) ) );
-      if ( result.PQresultStatus() == PGRES_TUPLES_OK )
+      if ( conn )
       {
-        srs = QgsCoordinateReferenceSystem::fromProj4( result.PQgetvalue( 0, 0 ) );
-        sCrsCache.insert( srid, srs );
+        QgsPostgresResult result( conn->PQexec( QStringLiteral( "SELECT proj4text FROM spatial_ref_sys WHERE srid=%1" ).arg( srid ) ) );
+        if ( result.PQresultStatus() == PGRES_TUPLES_OK )
+        {
+          srs = QgsCoordinateReferenceSystem::fromProj4( result.PQgetvalue( 0, 0 ) );
+          sCrsCache.insert( srid, srs );
+        }
       }
     }
   }