Tolerance for wrong pixels, better cleanup

tests/src/core/qgscompositionchecker.cpp

@@ -98,5 +98,9 @@ bool QgsCompositionChecker::compareImages( const QImage& img1, const QImage& img
       }
     }
   }
-  return mismatchCount < 1;
+
+  int pixelCount = imageWidth * imageHeight;
+
+  //allow pixel deviation of 1 percent
+  return (( double )mismatchCount / ( double )pixelCount ) < 0.01;
 }

tests/src/core/testqgscomposermap.cpp

@@ -72,6 +72,7 @@ void TestQgsComposerMap::cleanupTestCase()
 {
   delete mComposition;
   delete mMapRenderer;
+  delete mRasterLayer;
 }
 
 void TestQgsComposerMap::init()