Merge branch '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-2 into 4.7-integration

* '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-2:
  Fixed potential crash when loading corrupt GIFs.
  Work around an ATI driver problem with mutli-sampled pbuffers.
  tst_qstatemachine.cpp: fix compilation with Sun Studio
  Fixed regression in clipping.qps autotest on 64-bit.
  Fixed crash when using Qt::WA_DeleteOnClose on a QPrintDialog on Mac.
  Fixed performance regression in curve stroking.
  Don't disable texture_from_pixmap on GLX/X11 by default.
  Avoid creating copy of an image in memory when storing as png
  Doc update for the support of MSVC 2010 64-bit
  fix documentation of drawText(int, int, int, int, ...
  Optimization of pixel conversion when storing jpeg
  Don't pretend to support single buffered EGL surfaces.
  Named anonymous struct in the OpenGL paint engine.
  Fixes gray_raster incorrectly reporting out of memory error.

1 files changed, 18 insertions, 11 deletions

diff --git a/src/opengl/qglpixelbuffer_win.cpp b/src/opengl/qglpixelbuffer_win.cpp
index b55f383..c61d9bf 100644
--- a/src/opengl/qglpixelbuffer_win.cpp
+++ b/src/opengl/qglpixelbuffer_win.cpp
@@ -172,6 +172,10 @@ typedef BOOL (WINAPI * PFNWGLSETPBUFFERATTRIBARBPROC) (HPBUFFERARB hPbuffer, con
 #define WGL_SAMPLES_ARB                0x2042
 #endif
 
+#ifndef GL_SAMPLES_ARB
+#define GL_SAMPLES_ARB 0x80A9
+#endif
+
 QGLFormat pfiToQGLFormat(HDC hdc, int pfi);
 
 static void qt_format_to_attrib_list(bool has_render_texture, const QGLFormat &f, int attribs[])
@@ -242,8 +246,7 @@ static void qt_format_to_attrib_list(bool has_render_texture, const QGLFormat &f
 
 bool QGLPixelBufferPrivate::init(const QSize &size, const QGLFormat &f, QGLWidget *shareWidget)
 {
-    QGLWidget dmy;
-    dmy.makeCurrent(); // needed for wglGetProcAddress() to succeed
+    QGLTemporaryContext tempContext;
 
     PFNWGLCREATEPBUFFERARBPROC wglCreatePbufferARB =
         (PFNWGLCREATEPBUFFERARBPROC) wglGetProcAddress("wglCreatePbufferARB");
@@ -257,13 +260,12 @@ bool QGLPixelBufferPrivate::init(const QSize &size, const QGLFormat &f, QGLWidge
     if (!wglCreatePbufferARB) // assumes that if one can be resolved, all of them can
         return false;
 
-    dc = GetDC(dmy.winId());
+    dc = wglGetCurrentDC();
     Q_ASSERT(dc);
+    has_render_texture = false;
 
     // sample buffers doesn't work in conjunction with the render_texture extension
-    if (f.sampleBuffers()) {
-        has_render_texture = false;
-    } else {
+    if (!f.sampleBuffers()) {
         PFNWGLGETEXTENSIONSSTRINGARBPROC wglGetExtensionsStringARB =
                 (PFNWGLGETEXTENSIONSSTRINGARBPROC) wglGetProcAddress("wglGetExtensionsStringARB");
 
@@ -292,7 +294,6 @@ bool QGLPixelBufferPrivate::init(const QSize &size, const QGLFormat &f, QGLWidge
 
     if (num_formats == 0) {
         qWarning("QGLPixelBuffer: Unable to find a pixel format with pbuffer  - giving up.");
-        ReleaseDC(dmy.winId(), dc);
         return false;
     }
     format = pfiToQGLFormat(dc, pixel_format);
@@ -305,26 +306,32 @@ bool QGLPixelBufferPrivate::init(const QSize &size, const QGLFormat &f, QGLWidge
 
     pbuf = wglCreatePbufferARB(dc, pixel_format, size.width(), size.height(),
                                has_render_texture ? pb_attribs : 0);
-    if(!pbuf) {
+    if (!pbuf) {
         // try again without the render_texture extension
         pbuf = wglCreatePbufferARB(dc, pixel_format, size.width(), size.height(), 0);
         has_render_texture = false;
         if (!pbuf) {
             qWarning("QGLPixelBuffer: Unable to create pbuffer [w=%d, h=%d] - giving up.", size.width(), size.height());
-            ReleaseDC(dmy.winId(), dc);
             return false;
         }
     }
 
-    ReleaseDC(dmy.winId(), dc);
     dc = wglGetPbufferDCARB(pbuf);
     ctx = wglCreateContext(dc);
-
     if (!dc || !ctx) {
         qWarning("QGLPixelBuffer: Unable to create pbuffer context - giving up.");
         return false;
     }
 
+    // Explicitly disable the render_texture extension if we have a 
+    // multi-sampled pbuffer context. This seems to be a problem only with 
+    // ATI cards if multi-sampling is forced globally in the driver.
+    wglMakeCurrent(dc, ctx);
+    GLint samples = 0;
+    glGetIntegerv(GL_SAMPLES_ARB, &samples);
+    if (has_render_texture && samples != 0)
+        has_render_texture = false;
+
     HGLRC share_ctx = shareWidget ? shareWidget->d_func()->glcx->d_func()->rc : 0;
     if (share_ctx && !wglShareLists(share_ctx, ctx))
         qWarning("QGLPixelBuffer: Unable to share display lists - with share widget.");