fix #95: Update target dimensions after changing stage scale

Author: adazem009

src/renderedtarget.cpp

@@ -307,6 +307,7 @@ void RenderedTarget::setStageScale(double newStageScale)
     m_stageScale = newStageScale;
     calculateSize();
     calculatePos();
+    beforeRedraw();
     emit stageScaleChanged();
 }
 

test/renderedtarget/renderedtarget_test.cpp

@@ -270,6 +270,13 @@ TEST_F(RenderedTargetTest, UpdateMethods)
     ASSERT_EQ(texture.width(), 26);
     ASSERT_EQ(texture.height(), 26);
 
+    // Stage scale (SVG) - should update width and height
+    EXPECT_CALL(engine, stageWidth()).WillOnce(Return(480));
+    EXPECT_CALL(engine, stageHeight()).WillOnce(Return(360));
+    target.setStageScale(3.5);
+    ASSERT_EQ(target.width(), 52);
+    ASSERT_EQ(target.height(), 52);
+
     context.doneCurrent();
 }