Test vectorscope switching red and blue

Tests for BUG 453149, where the vectorscope switches red and blue on
Windows due to RGB vs BGR image data.

tests/CMakeLists.txt

@@ -5,6 +5,7 @@ kde_enable_exceptions()
 add_executable(runTests
     TestMain.cpp
     abortutil.cpp
+    colorscopestest.cpp
     compositiontest.cpp
     effectstest.cpp
     filetest.cpp

tests/colorscopestest.cpp

+#include "test_utils.hpp"
+
+#include "scopes/colorscopes/vectorscopegenerator.h"
+
+TEST_CASE("Vectorscope")
+{
+    // create a fully red image
+    QImage inputImage(480, 320, QImage::Format_RGB32);
+    inputImage.fill(Qt::red);
+    VectorscopeGenerator vectorscope{};
+
+    QSize scopeSize{256, 256};
+
+    // test for a bug where pixels were assumed to be RGB which was not true on
+    // Windows, resulting in red and blue switched. BUG: 453149
+    SECTION("Vectorscope handles both RGB and BGR")
+    {
+        QImage rgbScope = vectorscope.calculateVectorscope(scopeSize, inputImage, 1,
+            VectorscopeGenerator::PaintMode::PaintMode_Green2,
+            VectorscopeGenerator::ColorSpace::ColorSpace_YUV,
+            false, 7);
+
+        QImage bgrInputImage = inputImage.convertToFormat(QImage::Format_BGR30);
+        QImage bgrScope = vectorscope.calculateVectorscope(scopeSize, bgrInputImage, 1,
+            VectorscopeGenerator::PaintMode::PaintMode_Green2,
+            VectorscopeGenerator::ColorSpace::ColorSpace_YUV,
+            false, 7);
+
+        // both of these should be equivalent, since the vectorscope should
+        // handle different pixel formats
+        CHECK(rgbScope == bgrScope);
+    }
+}