From 0b6b67ca073dd778d7ad803dab1fa2bcae4a8c8a Mon Sep 17 00:00:00 2001
From: Ulf Hermann <ulf.hermann@digia.com>
Date: Tue, 25 Feb 2014 17:08:26 +0100
Subject: [PATCH] QmlProfiler: Don't use the canvas context if it isn't ready

The documentation indicates that onPaint can actually be called
while the context isn't ready.

Change-Id: I32d861e016e5e990f3d940a35ec28956902041ba
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
---
 src/plugins/qmlprofiler/qml/Overview.qml    | 2 ++
 src/plugins/qmlprofiler/qml/TimeDisplay.qml | 2 ++
 src/plugins/qmlprofiler/qml/TimeMarks.qml   | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/src/plugins/qmlprofiler/qml/Overview.qml b/src/plugins/qmlprofiler/qml/Overview.qml
index 9fed5a9c37c..40869602525 100644
--- a/src/plugins/qmlprofiler/qml/Overview.qml
+++ b/src/plugins/qmlprofiler/qml/Overview.qml
@@ -92,6 +92,8 @@ Canvas {
 
     // ***** slots
     onPaint: {
+        if (context === null)
+            return; // canvas isn't ready
         Plotter.qmlProfilerModelProxy = qmlProfilerModelProxy;
         if (dataReady) {
             Plotter.plot(canvas, context, region);
diff --git a/src/plugins/qmlprofiler/qml/TimeDisplay.qml b/src/plugins/qmlprofiler/qml/TimeDisplay.qml
index 107a5678d9e..12cecf435f1 100644
--- a/src/plugins/qmlprofiler/qml/TimeDisplay.qml
+++ b/src/plugins/qmlprofiler/qml/TimeDisplay.qml
@@ -49,6 +49,8 @@ Canvas {
     }
 
     onPaint: {
+        if (context === null)
+            return; // canvas isn't ready
         context.fillStyle = "white";
         context.fillRect(0, 0, width, height);
 
diff --git a/src/plugins/qmlprofiler/qml/TimeMarks.qml b/src/plugins/qmlprofiler/qml/TimeMarks.qml
index 6bf6be330cd..f9ac8e3590e 100644
--- a/src/plugins/qmlprofiler/qml/TimeMarks.qml
+++ b/src/plugins/qmlprofiler/qml/TimeMarks.qml
@@ -47,6 +47,8 @@ Canvas {
     onYChanged: requestPaint()
 
     onPaint: {
+        if (context === null)
+            return; // canvas isn't ready
         drawBackgroundBars( context, region );
 
         var totalTime = endTime - startTime;