Fixed wrong painting when doing IntersectClip after setClipping(false).

The documentation is a bit ambiguous on what the expected behavior here
is, but the behavior was consistent across paint engines before 4.5.
QPaintEngineEx introduced inconsistencies in the raster and OpenGL paint
engines, so this patch reverts the behavior back to what it was in 4.4.

Task-number: 256549
Reviewed-by: Trond

4 files changed, 29 insertions, 11 deletions

diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp
index 84af880..8e91101 100644
--- a/src/gui/painting/qpaintengine_raster.cpp
+++ b/src/gui/painting/qpaintengine_raster.cpp
@@ -1315,6 +1315,7 @@ void QRasterPaintEngine::clip(const QRect &rect, Qt::ClipOperation op)
             delete s->clip;
 
         s->clip = clip;
+        s->clip->enabled = true;
         s->flags.has_clip_ownership = true;
 
     } else { // intersect clip with current clip
@@ -1331,6 +1332,7 @@ void QRasterPaintEngine::clip(const QRect &rect, Qt::ClipOperation op)
                 s->clip->setClipRect(base->clipRect & clipRect);
             else
                 s->clip->setClipRegion(base->clipRegion & clipRect);
+            s->clip->enabled = true;
         } else {
             QPaintEngineEx::clip(rect, op);
             return;
diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index 3a5746a..d6c1c74 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -2565,6 +2565,9 @@ void QPainter::setClipRect(const QRectF &rect, Qt::ClipOperation op)
     Q_D(QPainter);
 
     if (d->extended) {
+        if (!hasClipping() && (op == Qt::IntersectClip || op == Qt::UniteClip))
+            op = Qt::ReplaceClip;
+
         if (!d->engine) {
             qWarning("QPainter::setClipRect: Painter not active");
             return;
@@ -2618,6 +2621,9 @@ void QPainter::setClipRect(const QRect &rect, Qt::ClipOperation op)
         return;
     }
 
+    if (!hasClipping() && (op == Qt::IntersectClip || op == Qt::UniteClip))
+        op = Qt::ReplaceClip;
+
     if (d->extended) {
         d->state->clipEnabled = true;
         d->extended->clip(rect, op);
@@ -2626,9 +2632,6 @@ void QPainter::setClipRect(const QRect &rect, Qt::ClipOperation op)
         return;
     }
 
-    if (!hasClipping() && (op == Qt::IntersectClip || op == Qt::UniteClip))
-        op = Qt::ReplaceClip;
-
     d->state->clipRegion = rect;
     d->state->clipOperation = op;
     if (op == Qt::NoClip || op == Qt::ReplaceClip)
@@ -2671,6 +2674,9 @@ void QPainter::setClipRegion(const QRegion &r, Qt::ClipOperation op)
         return;
     }
 
+    if (!hasClipping() && (op == Qt::IntersectClip || op == Qt::UniteClip))
+        op = Qt::ReplaceClip;
+
     if (d->extended) {
         d->state->clipEnabled = true;
         d->extended->clip(r, op);
@@ -2679,9 +2685,6 @@ void QPainter::setClipRegion(const QRegion &r, Qt::ClipOperation op)
         return;
     }
 
-    if (!hasClipping() && (op == Qt::IntersectClip || op == Qt::UniteClip))
-        op = Qt::ReplaceClip;
-
     d->state->clipRegion = r;
     d->state->clipOperation = op;
     if (op == Qt::NoClip || op == Qt::ReplaceClip)
@@ -3068,6 +3071,9 @@ void QPainter::setClipPath(const QPainterPath &path, Qt::ClipOperation op)
         return;
     }
 
+    if (!hasClipping() && (op == Qt::IntersectClip || op == Qt::UniteClip))
+        op = Qt::ReplaceClip;
+
     if (d->extended) {
         d->state->clipEnabled = true;
         d->extended->clip(path, op);
@@ -3076,11 +3082,6 @@ void QPainter::setClipPath(const QPainterPath &path, Qt::ClipOperation op)
         return;
     }
 
-
-
-    if (!hasClipping() && (op == Qt::IntersectClip || op == Qt::UniteClip))
-        op = Qt::ReplaceClip;
-
     d->state->clipPath = path;
     d->state->clipOperation = op;
     if (op == Qt::NoClip || op == Qt::ReplaceClip)
diff --git a/tests/arthur/data/qps/clipping_state.qps b/tests/arthur/data/qps/clipping_state.qps
index fd9a80a..3a66122 100644
--- a/tests/arthur/data/qps/clipping_state.qps
+++ b/tests/arthur/data/qps/clipping_state.qps
@@ -55,3 +55,18 @@ setClipping true
 
 setBrush #6300ff00
 drawRect 25 25 50 50
+
+# disable clipping followed by setClipRect
+translate 150 0
+
+setClipRect 0 0 50 50 ReplaceClip
+
+setClipping false
+
+setBrush #630000ff
+drawRect 0 0 100 100
+
+setClipRect 25 25 75 75 IntersectClip
+
+setBrush #6300ff00
+drawRect 25 25 50 50
diff --git a/tests/arthur/data/qps/clipping_state_qps.png b/tests/arthur/data/qps/clipping_state_qps.png
index 9b3dee2..28bee46 100644
--- a/tests/arthur/data/qps/clipping_state_qps.png
+++ b/tests/arthur/data/qps/clipping_state_qps.png