[fix #18892] avoid high jumps by setting a minimum pixel size for rect in map tool zoom

Author: 3nids

src/gui/qgsmaptoolzoom.cpp

@@ -91,14 +91,16 @@ void QgsMapToolZoom::canvasReleaseEvent( QgsMapMouseEvent *e )
   // We are not really dragging in this case. This is sometimes caused by
   // a pen based computer reporting a press, move, and release, all the
   // one point.
-  if ( mDragging && ( mZoomRect.topLeft() == mZoomRect.bottomRight() ) )
+  if ( !mDragging || ( mZoomRect.topLeft() - mZoomRect.bottomRight() ).manhattanLength() < mMinPixelZoom )
   {
     mDragging = false;
     delete mRubberBand;
     mRubberBand = nullptr;
-  }
 
-  if ( mDragging )
+    // change to zoom in/out by the default multiple
+    mCanvas->zoomWithCenter( e->x(), e->y(), !zoomOut );
+  }
+  else
   {
     mDragging = false;
     delete mRubberBand;
@@ -126,11 +128,6 @@ void QgsMapToolZoom::canvasReleaseEvent( QgsMapMouseEvent *e )
 
     mCanvas->refresh();
   }
-  else // not dragging
-  {
-    // change to zoom in/out by the default multiple
-    mCanvas->zoomWithCenter( e->x(), e->y(), !zoomOut );
-  }
 }
 
 void QgsMapToolZoom::deactivate()

src/gui/qgsmaptoolzoom.h

@@ -45,6 +45,8 @@ class GUI_EXPORT QgsMapToolZoom : public QgsMapTool
   protected:
     //! stores actual zoom rect
     QRect mZoomRect;
+    // minimum pixel size of diagonal of the zoom rectangle
+    int mMinPixelZoom = 20;
 
     //! indicates whether we're zooming in or out
     bool mZoomOut;