Prevent QTransform::type() from returning TxScale instead of TxProject.

We have code that assumes that m33 = 1 if the type is TxScale. Instead
of changing all that code it's better to just return TxProject as type
when m33 is different from 1.

Reviewed-by: Simon Hausmann

2 files changed, 12 insertions, 2 deletions

diff --git a/src/gui/painting/qtransform.cpp b/src/gui/painting/qtransform.cpp
index 39e429d..af27fd5 100644
--- a/src/gui/painting/qtransform.cpp
+++ b/src/gui/painting/qtransform.cpp
@@ -1880,7 +1880,7 @@ const QMatrix &QTransform::toAffine() const
 QTransform::TransformationType QTransform::type() const
 {
     if (m_dirty >= m_type) {
-        if (m_dirty > TxShear && (!qFuzzyCompare(m_13 + 1, 1) || !qFuzzyCompare(m_23 + 1, 1)))
+        if (m_dirty > TxShear && (!qFuzzyCompare(m_13 + 1, 1) || !qFuzzyCompare(m_23 + 1, 1) || !qFuzzyCompare(m_33, 1)))
              m_type = TxProject;
         else if (m_dirty > TxScale && (!qFuzzyCompare(affine._m12 + 1, 1) || !qFuzzyCompare(affine._m21 + 1, 1))) {
             const qreal dot = affine._m11 * affine._m12 + affine._m21 * affine._m22;
@@ -1888,7 +1888,7 @@ QTransform::TransformationType QTransform::type() const
                 m_type = TxRotate;
             else
                 m_type = TxShear;
-        } else if (m_dirty > TxTranslate && (!qFuzzyCompare(affine._m11, 1) || !qFuzzyCompare(affine._m22, 1) || !qFuzzyCompare(m_33, 1)))
+        } else if (m_dirty > TxTranslate && (!qFuzzyCompare(affine._m11, 1) || !qFuzzyCompare(affine._m22, 1)))
             m_type = TxScale;
         else if (m_dirty > TxNone && (!qFuzzyCompare(affine._dx + 1, 1) || !qFuzzyCompare(affine._dy + 1, 1)))
             m_type = TxTranslate;
diff --git a/tests/auto/qtransform/tst_qtransform.cpp b/tests/auto/qtransform/tst_qtransform.cpp
index 8516ddb..74c405e 100644
--- a/tests/auto/qtransform/tst_qtransform.cpp
+++ b/tests/auto/qtransform/tst_qtransform.cpp
@@ -593,6 +593,16 @@ void tst_QTransform::types()
     m3.translate(5.0f, 5.0f);
     QCOMPARE(m3.type(), QTransform::TxScale);
     QCOMPARE(m3.inverted().type(), QTransform::TxScale);
+
+    m3.setMatrix(1.0f, 0.0f, 0.0f,
+                 0.0f, 1.0f, 0.0f,
+                 0.0f, 0.0f, 2.0f);
+    QCOMPARE(m3.type(), QTransform::TxProject);
+
+    m3.setMatrix(0.0f, 2.0f, 0.0f,
+                 1.0f, 0.0f, 0.0f,
+                 0.0f, 0.0f, 2.0f);
+    QCOMPARE(m3.type(), QTransform::TxProject);
 }