Merge pull request #8184 from rouault/fix_20098

rouault · web-flow · commit b777ab23b186 · 2018-10-15T11:09:43.000+02:00
[OGR provider] Make again a feature iterator to be resetable on a OSM layer (fixes #20098)
diff --git a/src/providers/ogr/qgsogrfeatureiterator.cpp b/src/providers/ogr/qgsogrfeatureiterator.cpp
@@ -311,7 +311,7 @@ bool QgsOgrFeatureIterator::fetchFeature( QgsFeature &feature )
   // see more details here: https://trac.osgeo.org/gdal/wiki/rfc66_randomlayerreadwrite
 
 #if GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(2,2,0)
-  if ( mSource->mDriverName == QLatin1String( "OSM" ) )
+  if ( !QgsOgrProviderUtils::canDriverShareSameDatasetAmongLayers( mSource->mDriverName ) )
   {
     OGRLayerH nextFeatureBelongingLayer;
     while ( fet.reset( GDALDatasetGetNextFeature( mConn->ds, &nextFeatureBelongingLayer, nullptr, nullptr, nullptr ) ), fet )
@@ -323,6 +323,7 @@ bool QgsOgrFeatureIterator::fetchFeature( QgsFeature &feature )
     }
   }
   else
+#endif
   {
 
     while ( fet.reset( OGR_L_GetNextFeature( mOgrLayer ) ), fet )
@@ -333,20 +334,25 @@ bool QgsOgrFeatureIterator::fetchFeature( QgsFeature &feature )
       }
     }
   }
-#else
-  while ( fet.reset( OGR_L_GetNextFeature( mOgrLayer ) ), fet )
-  {
-    if ( checkFeature( fet, feature ) )
-    {
-      return true;
-    }
-  }
-#endif
 
   close();
   return false;
 }
 
+void QgsOgrFeatureIterator::resetReading()
+{
+#if GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(2,2,0)
+  if ( !QgsOgrProviderUtils::canDriverShareSameDatasetAmongLayers( mSource->mDriverName ) )
+  {
+    GDALDatasetResetReading( mConn->ds );
+  }
+  else
+#endif
+  {
+    OGR_L_ResetReading( mOgrLayer );
+  }
+}
+
 
 bool QgsOgrFeatureIterator::rewind()
 {
@@ -355,7 +361,7 @@ bool QgsOgrFeatureIterator::rewind()
   if ( mClosed || !mOgrLayer )
     return false;
 
-  OGR_L_ResetReading( mOgrLayer );
+  resetReading();
 
   mFilterFidsIt = mFilterFids.constBegin();
 
@@ -387,7 +393,7 @@ bool QgsOgrFeatureIterator::close()
   // Will for example release SQLite3 statements
   if ( mOgrLayer )
   {
-    OGR_L_ResetReading( mOgrLayer );
+    resetReading();
   }
 
   if ( mOgrOrigLayer )
diff --git a/src/providers/ogr/qgsogrfeatureiterator.h b/src/providers/ogr/qgsogrfeatureiterator.h
@@ -100,6 +100,8 @@ class QgsOgrFeatureIterator : public QgsAbstractFeatureIteratorFromSource<QgsOgr
     QgsFields mFieldsWithoutFid;
 
     bool fetchFeatureWithId( QgsFeatureId id, QgsFeature &feature ) const;
+
+    void resetReading();
 };
 
 #endif // QGSOGRFEATUREITERATOR_H
diff --git a/tests/src/python/test_provider_ogr.py b/tests/src/python/test_provider_ogr.py
@@ -454,6 +454,10 @@ def testOSM(self):
         self.assertTrue(iter_multipolygons.nextFeature(f))
         self.assertFalse(iter_multipolygons.nextFeature(f))
 
+        # Re-start an iterator (tests #20098)
+        iter_multipolygons = vl_multipolygons.getFeatures(QgsFeatureRequest())
+        self.assertTrue(iter_multipolygons.nextFeature(f))
+
 
 if __name__ == '__main__':
     unittest.main()

Original file line number	Diff line number	Diff line change
`@@ -311,7 +311,7 @@ bool QgsOgrFeatureIterator::fetchFeature( QgsFeature &feature )`
`311`	`311`	`// see more details here: https://trac.osgeo.org/gdal/wiki/rfc66_randomlayerreadwrite`
`312`	`312`
`313`	`313`	`#if GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(2,2,0)`
`314`		`- if ( mSource->mDriverName == QLatin1String( "OSM" ) )`
	`314`	`+ if ( !QgsOgrProviderUtils::canDriverShareSameDatasetAmongLayers( mSource->mDriverName ) )`
`315`	`315`	`{`
`316`	`316`	`OGRLayerH nextFeatureBelongingLayer;`
`317`	`317`	`while ( fet.reset( GDALDatasetGetNextFeature( mConn->ds, &nextFeatureBelongingLayer, nullptr, nullptr, nullptr ) ), fet )`
`@@ -323,6 +323,7 @@ bool QgsOgrFeatureIterator::fetchFeature( QgsFeature &feature )`
`323`	`323`	`}`
`324`	`324`	`}`
`325`	`325`	`else`
	`326`	`+#endif`
`326`	`327`	`{`
`327`	`328`
`328`	`329`	`while ( fet.reset( OGR_L_GetNextFeature( mOgrLayer ) ), fet )`
`@@ -333,20 +334,25 @@ bool QgsOgrFeatureIterator::fetchFeature( QgsFeature &feature )`
`333`	`334`	`}`
`334`	`335`	`}`
`335`	`336`	`}`
`336`		`-#else`
`337`		`- while ( fet.reset( OGR_L_GetNextFeature( mOgrLayer ) ), fet )`
`338`		`- {`
`339`		`- if ( checkFeature( fet, feature ) )`
`340`		`- {`
`341`		`- return true;`
`342`		`- }`
`343`		`- }`
`344`		`-#endif`
`345`	`337`
`346`	`338`	`close();`
`347`	`339`	`return false;`
`348`	`340`	`}`
`349`	`341`
	`342`	`+void QgsOgrFeatureIterator::resetReading()`
	`343`	`+{`
	`344`	`+#if GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(2,2,0)`
	`345`	`+ if ( !QgsOgrProviderUtils::canDriverShareSameDatasetAmongLayers( mSource->mDriverName ) )`
	`346`	`+ {`
	`347`	`+ GDALDatasetResetReading( mConn->ds );`
	`348`	`+ }`
	`349`	`+ else`
	`350`	`+#endif`
	`351`	`+ {`
	`352`	`+ OGR_L_ResetReading( mOgrLayer );`
	`353`	`+ }`
	`354`	`+}`
	`355`	`+`
`350`	`356`
`351`	`357`	`bool QgsOgrFeatureIterator::rewind()`
`352`	`358`	`{`
`@@ -355,7 +361,7 @@ bool QgsOgrFeatureIterator::rewind()`
`355`	`361`	`if ( mClosed \|\| !mOgrLayer )`
`356`	`362`	`return false;`
`357`	`363`
`358`		`- OGR_L_ResetReading( mOgrLayer );`
	`364`	`+ resetReading();`
`359`	`365`
`360`	`366`	`mFilterFidsIt = mFilterFids.constBegin();`
`361`	`367`
`@@ -387,7 +393,7 @@ bool QgsOgrFeatureIterator::close()`
`387`	`393`	`// Will for example release SQLite3 statements`
`388`	`394`	`if ( mOgrLayer )`
`389`	`395`	`{`
`390`		`- OGR_L_ResetReading( mOgrLayer );`
	`396`	`+ resetReading();`
`391`	`397`	`}`
`392`	`398`
`393`	`399`	`if ( mOgrOrigLayer )`