Fixed QPainter::drawPolyline() not drawing solid lines.

If a line segment isn't filled we keep using the same point of origin.

Task-number: QTBUG-26156
Change-Id: I20af8410a7039b69848f201ab62fd3c01b95531b
Reviewed-by: Titta Heikkala <titta.heikkala@digia.com>
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>

1 files changed, 16 insertions, 1 deletions

diff --git a/src/gui/painting/qcosmeticstroker.cpp b/src/gui/painting/qcosmeticstroker.cpp
index 1de955bc13..7f53bec52f 100644
--- a/src/gui/painting/qcosmeticstroker.cpp
+++ b/src/gui/painting/qcosmeticstroker.cpp
@@ -583,6 +583,7 @@ void QCosmeticStroker::drawPath(const QVectorPath &path)
         patternOffset = state->lastPen.dashOffset()*64;
         lastPixel.x = -1;
 
+        const qreal *begin = points;
         const qreal *end = points + 2*path.elementCount();
         // handle closed path case
         bool closed = path.hasImplicitClose() || (points[0] == end[-2] && points[1] == end[-1]);
@@ -592,6 +593,7 @@ void QCosmeticStroker::drawPath(const QVectorPath &path)
             calculateLastPoint(p2.x(), p2.y(), p.x(), p.y());
         }
 
+        bool fastPenAliased = (state->flags.fast_pen && !state->flags.antialiased);
         points += 2;
         while (points < end) {
             QPointF p2 = QPointF(points[0], points[1]) * state->matrix;
@@ -599,9 +601,22 @@ void QCosmeticStroker::drawPath(const QVectorPath &path)
             if (!closed && drawCaps && points == end - 2)
                 caps |= CapEnd;
 
+            QCosmeticStroker::Point last = this->lastPixel;
             stroke(this, p.x(), p.y(), p2.x(), p2.y(), caps);
 
-            p = p2;
+            /* fix for gaps in polylines with fastpen and aliased in a sequence
+               of points with small distances: if current point p2 has been dropped
+               out, keep last non dropped point p. */
+            if (fastPenAliased) {
+                if (last.x != lastPixel.x || last.y != lastPixel.y ||
+                    points == begin + 2 || points == end - 2 ) {
+                    {
+                        p = p2;
+                    }
+                }
+            } else {
+                p = p2;
+            }
             points += 2;
             caps = NoCaps;
         }