Geom checker plugin: don't crash if feedback is 0x0

Fixes #21259

Author: elpaso

src/analysis/vector/geometry_checker/qgsgeometrygapcheck.cpp

@@ -45,7 +45,7 @@ void QgsGeometryGapCheck::collectErrors( const QMap<QString, QgsFeaturePool *> &
   {
     geomList.append( layerFeature.geometry() );
 
-    if ( feedback->isCanceled() )
+    if ( feedback && feedback->isCanceled() )
     {
       geomList.clear();
       break;

src/analysis/vector/geometry_checker/qgsgeometrymissingvertexcheck.cpp

@@ -43,7 +43,7 @@ void QgsGeometryMissingVertexCheck::collectErrors( const QMap<QString, QgsFeatur
 
   for ( const QgsGeometryCheckerUtils::LayerFeature &layerFeature : layerFeatures )
   {
-    if ( feedback->isCanceled() )
+    if ( feedback && feedback->isCanceled() )
     {
       break;
     }
@@ -152,7 +152,7 @@ void QgsGeometryMissingVertexCheck::processPolygon( const QgsCurvePolygon *polyg
 
     if ( featurePool->getFeature( fid, compareFeature, feedback ) )
     {
-      if ( feedback->isCanceled() )
+      if ( feedback && feedback->isCanceled() )
         break;
 
       QgsVertexIterator vertexIterator = compareFeature.geometry().vertices();

src/analysis/vector/geometry_checker/qgsgeometryoverlapcheck.cpp

@@ -35,7 +35,7 @@ void QgsGeometryOverlapCheck::collectErrors( const QMap<QString, QgsFeaturePool
   QList<QString> layerIds = featureIds.keys();
   for ( const QgsGeometryCheckerUtils::LayerFeature &layerFeatureA : layerFeaturesA )
   {
-    if ( feedback->isCanceled() )
+    if ( feedback && feedback->isCanceled() )
       break;
 
     // Ensure each pair of layers only gets compared once: remove the current layer from the layerIds, but add it to the layerList for layerFeaturesB
@@ -52,7 +52,7 @@ void QgsGeometryOverlapCheck::collectErrors( const QMap<QString, QgsFeaturePool
     const QgsGeometryCheckerUtils::LayerFeatures layerFeaturesB( featurePools, QList<QString>() << layerFeatureA.layer()->id() << layerIds, bboxA, compatibleGeometryTypes(), mContext );
     for ( const QgsGeometryCheckerUtils::LayerFeature &layerFeatureB : layerFeaturesB )
     {
-      if ( feedback->isCanceled() )
+      if ( feedback && feedback->isCanceled() )
         break;
 
       // > : only report overlaps within same layer once