4 files changed, 16 insertions, 9 deletions
diff --git a/src/opengl/gl2paintengineex/qglengineshadermanager.cpp b/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
index ac25597..40b3641 100644
--- a/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
+++ b/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
@@ -266,10 +266,12 @@ QGLEngineShaderProg *QGLEngineSharedShaders::findProgramInCache(const QGLEngineS
 
     do {
         QByteArray source;
-        source.append(qShaderSnippets[prog.mainFragShader]);
-        source.append(qShaderSnippets[prog.srcPixelFragShader]);
+        // Insert the custom stage before the srcPixel shader to work around an ATI driver bug
+        // where you cannot forward declare a function that takes a sampler as argument.
         if (prog.srcPixelFragShader == CustomImageSrcFragmentShader)
             source.append(prog.customStageSource);
+        source.append(qShaderSnippets[prog.mainFragShader]);
+        source.append(qShaderSnippets[prog.srcPixelFragShader]);
         if (prog.compositionFragShader)
             source.append(qShaderSnippets[prog.compositionFragShader]);
         if (prog.maskFragShader)
@@ -777,8 +779,8 @@ bool QGLEngineShaderManager::useCorrectShaderProg()
     // doesn't use are disabled)
     QGLContextPrivate* ctx_d = ctx->d_func();
     ctx_d->setVertexAttribArrayEnabled(QT_VERTEX_COORDS_ATTR, true);
-    ctx_d->setVertexAttribArrayEnabled(QT_TEXTURE_COORDS_ATTR, currentShaderProg->useTextureCoords);
-    ctx_d->setVertexAttribArrayEnabled(QT_OPACITY_ATTR, currentShaderProg->useOpacityAttribute);
+    ctx_d->setVertexAttribArrayEnabled(QT_TEXTURE_COORDS_ATTR, currentShaderProg && currentShaderProg->useTextureCoords);
+    ctx_d->setVertexAttribArrayEnabled(QT_OPACITY_ATTR, currentShaderProg && currentShaderProg->useOpacityAttribute);
 
     shaderProgNeedsChanging = false;
     return true;
diff --git a/src/opengl/gl2paintengineex/qglengineshadersource_p.h b/src/opengl/gl2paintengineex/qglengineshadersource_p.h
index 8dba951..a7ece0f 100644
--- a/src/opengl/gl2paintengineex/qglengineshadersource_p.h
+++ b/src/opengl/gl2paintengineex/qglengineshadersource_p.h
@@ -351,7 +351,6 @@ static const char* const qglslImageSrcFragmentShader = "\n\
 static const char* const qglslCustomSrcFragmentShader = "\n\
     varying   highp   vec2      textureCoords; \n\
     uniform   lowp    sampler2D imageTexture; \n\
-    lowp vec4 customShader(lowp sampler2D texture, highp vec2 coords); \n\
     lowp vec4 srcPixel() \n\
     { \n\
         return customShader(imageTexture, textureCoords); \n\
diff --git a/src/opengl/qglpixmapfilter.cpp b/src/opengl/qglpixmapfilter.cpp
index d5a11d9..bfa5ef1 100644
--- a/src/opengl/qglpixmapfilter.cpp
+++ b/src/opengl/qglpixmapfilter.cpp
@@ -591,10 +591,11 @@ bool QGLPixmapDropShadowFilter::processGL(QPainter *painter, const QPointF &pos,
 
         qt_blurImage(image, r * qreal(0.5), false, 1);
 
-        GLuint texture = generateBlurTexture(image.size(), GL_ALPHA);
-
-        glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, image.width(), image.height(), GL_ALPHA,
-                        GL_UNSIGNED_BYTE, image.bits());
+        GLuint texture;
+        glGenTextures(1, &texture);
+        glBindTexture(GL_TEXTURE_2D, texture);
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, image.width(), image.height(),
+                     0, GL_ALPHA, GL_UNSIGNED_BYTE, image.bits());
 
         info = new QGLBlurTextureInfo(image, texture, r);
     }
diff --git a/src/opengl/qpaintengine_opengl.cpp b/src/opengl/qpaintengine_opengl.cpp
index 08a50cb..28d37bc 100644
--- a/src/opengl/qpaintengine_opengl.cpp
+++ b/src/opengl/qpaintengine_opengl.cpp
@@ -1451,6 +1451,11 @@ bool QOpenGLPaintEngine::end()
     d->device->endPaint();
     qt_mask_texture_cache()->maintainCache();
 
+#if defined(Q_WS_X11)
+    // clear out the references we hold for textures bound with the
+    // texture_from_pixmap extension
+    ctx->d_func()->boundPixmaps.clear();
+#endif
     return true;
 }