Diagonal dashes are moving when touching the clip boundary.

We normally pad the clip rect with the size of the pen and miterlimit
to avoid this, but this didn't handle the case where there was a long
diagonal dash. We also need to multiply the padding with the longest
dash.

Reviewed-By: Tom Cooksey

1 files changed, 4 insertions, 1 deletions

diff --git a/src/gui/painting/qstroker.cpp b/src/gui/painting/qstroker.cpp
index ceafe4c397..362b0b3fa0 100644
--- a/src/gui/painting/qstroker.cpp
+++ b/src/gui/painting/qstroker.cpp
@@ -1012,10 +1012,13 @@ void QDashStroker::processCurrentSubpath()
     int dashCount = qMin(m_dashPattern.size(), 32);
     qfixed dashes[32];
 
+    qreal longestLength = 0;
     qreal sumLength = 0;
     for (int i=0; i<dashCount; ++i) {
         dashes[i] = qMax(m_dashPattern.at(i), qreal(0)) * m_stroker->strokeWidth();
         sumLength += dashes[i];
+        if (dashes[i] > longestLength)
+            longestLength = dashes[i];
     }
 
     if (qFuzzyCompare(sumLength + 1, qreal(1)))
@@ -1053,7 +1056,7 @@ void QDashStroker::processCurrentSubpath()
     qfixed2d line_to_pos;
 
     // Pad to avoid clipping the borders of thick pens.
-    qfixed padding = qMax(m_stroker->strokeWidth(), m_stroker->miterLimit());
+    qfixed padding = qt_real_to_fixed(qMax(m_stroker->strokeWidth(), m_stroker->miterLimit()) * longestLength);
     qfixed2d clip_tl = { qt_real_to_fixed(m_clip_rect.left()) - padding,
                          qt_real_to_fixed(m_clip_rect.top()) - padding };
     qfixed2d clip_br = { qt_real_to_fixed(m_clip_rect.right()) + padding ,