Fix more occurances of drawPolygon issues on Windows

Author: nyalldawson

src/core/composer/qgscomposeritem.cpp

@@ -525,7 +525,13 @@ void QgsComposerItem::drawSelectionBoxes( QPainter* p )
     selectedItemPen.setWidth( 0 );
     p->setPen( selectedItemPen );
     p->setBrush( Qt::NoBrush );
-    p->drawPolygon( rect() );
+
+    // drawPolygon causes issues on windows - corners of path may be missing resulting in triangles being drawn
+    // instead of rectangles! (Same cause as #13343)
+    QPainterPath path;
+    path.addPolygon( rect() );
+    p->drawPath( path );
+
     p->restore();
   }
 

src/gui/qgsmapoverviewcanvas.cpp

@@ -291,6 +291,11 @@ void QgsPanningWidget::setPolygon( const QPolygon& p )
 {
   if ( p == mPoly ) return;
   mPoly = p;
+
+  //ensure polygon is closed
+  if ( mPoly.at( 0 ) != mPoly.at( mPoly.length() - 1 ) )
+    mPoly.append( mPoly.at( 0 ) );
+
   setGeometry( p.boundingRect() );
   update();
 }
@@ -303,7 +308,13 @@ void QgsPanningWidget::paintEvent( QPaintEvent* pe )
   p.begin( this );
   p.setPen( Qt::red );
   QPolygonF t = mPoly.translated( -mPoly.boundingRect().left(), -mPoly.boundingRect().top() );
-  p.drawConvexPolygon( t );
+
+  // drawPolygon causes issues on windows - corners of path may be missing resulting in triangles being drawn
+  // instead of rectangles! (Same cause as #13343)
+  QPainterPath path;
+  path.addPolygon( t );
+  p.drawPath( path );
+
   p.end();
 }