postgres provider: convert M to Z geometries (fixes #9032)

src/providers/postgres/qgspostgresconn.cpp

@@ -1367,6 +1367,30 @@ QGis::WkbType QgsPostgresConn::wkbTypeFromPostgis( QString type )
   }
 }
 
+QGis::WkbType QgsPostgresConn::wkbTypeFromOgcWkbType( unsigned int wkbType )
+{
+  // polyhedralsurface / TIN / triangle => Polygon
+  if ( wkbType % 100 >= 15 )
+    wkbType = wkbType / 1000 * 1000 + QGis::WKBPolygon;
+
+  switch ( wkbType / 1000 )
+  {
+    case 0:
+      break;
+    case 1: // Z
+      wkbType = 0x80000000 + wkbType % 100;
+      break;
+    case 2: // M => Z
+      wkbType = 0x80000000 + wkbType % 100;
+      break;
+    case 3: // ZM
+      wkbType = 0xc0000000 + wkbType % 100;
+      break;
+  }
+
+  return ( QGis::WkbType ) wkbType;
+}
+
 QString QgsPostgresConn::displayStringForWkbType( QGis::WkbType type )
 {
   switch ( type )

src/providers/postgres/qgspostgresconn.h

@@ -246,6 +246,7 @@ class QgsPostgresConn : public QObject
     static QString postgisTypeFilter( QString geomCol, QGis::WkbType wkbType, bool isGeography );
 
     static QGis::WkbType wkbTypeFromGeomType( QGis::GeometryType geomType );
+    static QGis::WkbType wkbTypeFromOgcWkbType( unsigned int ogcWkbType );
 
     static QStringList connectionList();
     static QString selectedConnection();

src/providers/postgres/qgspostgresfeatureiterator.cpp

@@ -410,84 +410,22 @@ bool QgsPostgresFeatureIterator::getFeature( QgsPostgresResult &queryResult, int
         // modify 2.5D WKB types to make them compliant with OGR
         unsigned int wkbType;
         memcpy( &wkbType, featureGeom + 1, sizeof( wkbType ) );
-
-        // convert unsupported types to supported ones
-        switch ( wkbType )
-        {
-          case 15:
-            // 2D polyhedral => multipolygon
-            wkbType = 6;
-            break;
-          case 1015:
-            // 3D polyhedral => multipolygon
-            wkbType = 1006;
-            break;
-          case 17:
-            // 2D triangle => polygon
-            wkbType = 3;
-            break;
-          case 1017:
-            // 3D triangle => polygon
-            wkbType = 1003;
-            break;
-          case 16:
-            // 2D TIN => multipolygon
-            wkbType = 6;
-            break;
-          case 1016:
-            // TIN => multipolygon
-            wkbType = 1006;
-            break;
-        }
-        // convert from postgis types to qgis types
-        if ( wkbType >= 1000 )
-        {
-          wkbType = wkbType - 1000 + QGis::WKBPoint25D - 1;
-        }
+        wkbType = QgsPostgresConn::wkbTypeFromOgcWkbType( wkbType );
         memcpy( featureGeom + 1, &wkbType, sizeof( wkbType ) );
 
         // change wkb type of inner geometries
         if ( wkbType == QGis::WKBMultiPoint25D ||
              wkbType == QGis::WKBMultiLineString25D ||
              wkbType == QGis::WKBMultiPolygon25D )
         {
-          unsigned int numGeoms = *(( int* )( featureGeom + 5 ) );
-          unsigned char* wkb = featureGeom + 9;
+          unsigned int numGeoms;
+          memcpy( &numGeoms, featureGeom + 5, sizeof( unsigned int ) );
+          unsigned char *wkb = featureGeom + 9;
           for ( unsigned int i = 0; i < numGeoms; ++i )
           {
             unsigned int localType;
             memcpy( &localType, wkb + 1, sizeof( localType ) );
-            switch ( localType )
-            {
-              case 15:
-                // 2D polyhedral => multipolygon
-                localType = 6;
-                break;
-              case 1015:
-                // 3D polyhedral => multipolygon
-                localType = 1006;
-                break;
-              case 17:
-                // 2D triangle => polygon
-                localType = 3;
-                break;
-              case 1017:
-                // 3D triangle => polygon
-                localType = 1003;
-                break;
-              case 16:
-                // 2D TIN => multipolygon
-                localType = 6;
-                break;
-              case 1016:
-                // TIN => multipolygon
-                localType = 1006;
-                break;
-            }
-            if ( localType >= 1000 )
-            {
-              localType = localType - 1000 + QGis::WKBPoint25D - 1;
-            }
+            localType = QgsPostgresConn::wkbTypeFromOgcWkbType( localType );
             memcpy( wkb + 1, &localType, sizeof( localType ) );
 
             // skip endian and type info
@@ -501,21 +439,22 @@ bool QgsPostgresFeatureIterator::getFeature( QgsPostgresResult &queryResult, int
                 break;
               case QGis::WKBMultiLineString25D:
               {
-                unsigned int nPoints = *(( int* ) wkb );
-                wkb += sizeof( nPoints );
-                wkb += sizeof( double ) * 3 * nPoints;
+                unsigned int nPoints;
+                memcpy( &nPoints, wkb, sizeof( int ) );
+                wkb += sizeof( int ) + sizeof( double ) * 3 * nPoints;
               }
               break;
               default:
               case QGis::WKBMultiPolygon25D:
               {
-                unsigned int nRings = *(( int* ) wkb );
-                wkb += sizeof( nRings );
+                unsigned int nRings;
+                memcpy( &nRings, wkb, sizeof( int ) );
+                wkb += sizeof( int );
                 for ( unsigned int j = 0; j < nRings; ++j )
                 {
-                  unsigned int nPoints = *(( int* ) wkb );
-                  wkb += sizeof( nPoints );
-                  wkb += sizeof( double ) * 3 * nPoints;
+                  unsigned int nPoints;
+                  memcpy( &nPoints, wkb, sizeof( int ) );
+                  wkb += sizeof( nPoints ) + sizeof( double ) * 3 * nPoints;
                 }
               }
               break;