Fix for ticket #406 (problems with copying selected attributes from a…

… postgres

layer). Has the side-effect of eliminating the postgresql server 'no
transaction in progress warnings'.


git-svn-id: http://svn.osgeo.org/qgis/trunk@6171 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/providers/postgres/qgspostgresprovider.cpp

@@ -443,7 +443,8 @@ QgsFeature *QgsPostgresProvider::getNextFeature(bool fetchAttributes)
     //    std::cerr << "Error: " << PQerrorMessage(connection) << std::endl;
     //   std::cerr << "Fetched " << PQntuples(queryResult) << "rows" << std::endl;
     if(PQntuples(queryResult) == 0){
-      PQexec(connection, "end work");
+      if (ready)
+        PQexec(connection, "end work");
       ready = false;
       return 0;
     } 
@@ -525,7 +526,8 @@ QgsFeature* QgsPostgresProvider::getNextFeature(std::list<int> const & attlist,
       if (rows == 0)
       {
         QgsDebugMsg("End of features."); 
-        PQexec(connection, "end work");
+        if (ready)
+          PQexec(connection, "end work");
         ready = false;
         return 0;
       }
@@ -644,6 +646,7 @@ void QgsPostgresProvider::select(QgsRect * rect, bool useIntersect)
     PQexec(connection, "end work");
   }
   PQexec(connection,"begin work");
+  ready = true;
   PQexec(connection, (const char *)(declare.utf8()));
 
   // TODO - see if this deallocates member features
@@ -791,7 +794,10 @@ void QgsPostgresProvider::getFeatureGeometry(int key, QgsFeature *f)
 
   QgsDebugMsg("QgsPostgresProvider::getFeatureGeometry using: " + cursor); 
 
+  if (ready)
+    PQexec(connection, "end work");
   PQexec(connection, "begin work");
+  ready = true;
   PQexec(connection, (const char *)(cursor.utf8()));
 
   QString fetch = "fetch forward 1 from qgisf";
@@ -801,6 +807,7 @@ void QgsPostgresProvider::getFeatureGeometry(int key, QgsFeature *f)
   {
     // Nothing found - therefore nothing to change
     PQexec(connection,"end work");
+    ready = false;
     PQclear(geomResult);
     return;
   }
@@ -822,8 +829,9 @@ void QgsPostgresProvider::getFeatureGeometry(int key, QgsFeature *f)
 
   PQclear(geomResult);
 
-  PQexec(connection,"end work");
-
+  if (ready)
+    PQexec(connection,"end work");
+  ready = false;
 }
 
 
@@ -848,16 +856,17 @@ void QgsPostgresProvider::reset()
   QgsDebugMsg("Setting up binary cursor: " + declare);
 
   // set up the cursor
-  PQexec(connection,"end work");
+  if (ready)
+    PQexec(connection,"end work");
 
   PQexec(connection,"begin work");
+  ready = true;
   PQexec(connection, (const char *)(declare.utf8()));
   //QgsDebugMsg("Error: " + PQerrorMessage(connection));
 
   // TODO - see if this deallocates member features
   mFeatureQueue.empty();
 
-  ready = true;
 }
 /* QString QgsPostgresProvider::getFieldTypeName(PGconn * pd, int oid)
    {