diff -Naur qt-everywhere-opensource-src-4.7.0-orig/src/3rdparty/webkit/WebCore/platform/graphics/qt/GraphicsContextQt.cpp qt-everywhere-opensource-src-4.7.0/src/3rdparty/webkit/WebCore/platform/graphics/qt/GraphicsContextQt.cpp
--- qt-everywhere-opensource-src-4.7.0-orig/src/3rdparty/webkit/WebCore/platform/graphics/qt/GraphicsContextQt.cpp	2010-09-10 13:05:21 +0400
+++ qt-everywhere-opensource-src-4.7.0/src/3rdparty/webkit/WebCore/platform/graphics/qt/GraphicsContextQt.cpp	2010-10-10 12:13:18 +0400
@@ -51,6 +51,8 @@
 #include "Pattern.h"
 #include "Pen.h"
 
+#include <QtCore>
+
 #include <QBrush>
 #include <QDebug>
 #include <QGradient>
@@ -780,8 +782,31 @@
     if (paintingDisabled())
         return;
 
+#if !defined(Q_WS_X11)
     IntPoint endPoint = origin + IntSize(width, 0);
     drawLine(origin, endPoint);
+#else
+    IntPoint p1 = origin;
+    IntPoint p2 = origin + IntSize(width, 0);
+
+    // if paintengine type is X11 to avoid artifacts
+    // like bug https://bugs.webkit.org/show_bug.cgi?id=42248
+    QPainter* p = m_data->p();
+    if (p->paintEngine()->type() == QPaintEngine::X11) {
+        // If stroke thiknes is odd we need decrease Y coordinate by 1,
+        // because inside methotod adjustLineToPixelBoundaries(...), which
+        // called from drawLine(...), Y coordinate will be increased by 0.5f
+        // and then inside Qt painting engine will be rounded to next greater
+        // integer value
+        float strokeWidth = strokeThickness();
+        if (static_cast<int>(strokeWidth) % 2) { //odd
+            p1.setY(p1.y() - 1);
+            p2.setY(p2.y() - 1);
+        }
+    }
+
+    drawLine(p1, p2);
+#endif // !defined(Q_WS_X11)
 }
 
 void GraphicsContext::drawLineForMisspellingOrBadGrammar(const IntPoint&, int, bool)