Index: C:/repository/Qt48/qt/src/opengl/qgl.cpp
===================================================================
--- C:/repository/Qt48/qt/src/opengl/qgl.cpp	(revision 3159)
+++ C:/repository/Qt48/qt/src/opengl/qgl.cpp	(revision 3160)
@@ -1744,8 +1744,6 @@
     workaround_brokenTextureFromPixmap_init = false;
 
     workaround_brokenScissor = false;
-    workaround_brokenAlphaTexSubImage = false;
-    workaround_brokenAlphaTexSubImage_init = false;
 
     for (int i = 0; i < QT_GL_VERTEX_ARRAY_TRACKED_COUNT; ++i)
         vertexAttributeArraysEnabledState[i] = false;
Index: C:/repository/Qt48/qt/src/opengl/qgl_p.h
===================================================================
--- C:/repository/Qt48/qt/src/opengl/qgl_p.h	(revision 3159)
+++ C:/repository/Qt48/qt/src/opengl/qgl_p.h	(revision 3160)
@@ -429,8 +429,6 @@
     uint workaround_brokenTextureFromPixmap_init : 1;
 
     uint workaround_brokenScissor : 1;
-    uint workaround_brokenAlphaTexSubImage : 1;
-    uint workaround_brokenAlphaTexSubImage_init : 1;
 
 #ifndef QT_NO_EGL
     uint ownsEglContext : 1;
Index: C:/repository/Qt48/qt/src/opengl/gl2paintengineex/qtextureglyphcache_gl.cpp
===================================================================
--- C:/repository/Qt48/qt/src/opengl/gl2paintengineex/qtextureglyphcache_gl.cpp	(revision 3158)
+++ C:/repository/Qt48/qt/src/opengl/gl2paintengineex/qtextureglyphcache_gl.cpp	(revision 3159)
@@ -335,23 +335,25 @@
         // and nVidia GeForce 8500GT. GL_UNPACK_ALIGNMENT is set to four bytes, 'mask' has a
         // multiple of four bytes per line, and most of the glyph shows up correctly in the
         // texture, which makes me think that this is a driver bug.
-        // One workaround is to make sure the mask width is a multiple of four bytes, for instance
-        // by converting it to a format with four bytes per pixel. Another is to copy one line at a
-        // time.
-
-        if (!ctx->d_ptr->workaround_brokenAlphaTexSubImage_init) {
-            // don't know which driver versions exhibit this bug, so be conservative for now
-            const QByteArray versionString(reinterpret_cast<const char*>(glGetString(GL_VERSION)));
-            ctx->d_ptr->workaround_brokenAlphaTexSubImage = versionString.indexOf("NVIDIA") >= 0;
-            ctx->d_ptr->workaround_brokenAlphaTexSubImage_init = true;
+        // The solution to this is to upload larger glyphs with a glyph width of a multiple of 4, 
+        // since QImage contains the padding bytes anyways. We need to fill the padding bytes with 0
+        // and afterwards we can upload the glyph mask with a multiple of 4 width.
+        
+        // fill the padding bytes with 0 (QImage seems to have 0xff as default padding value)
+        quint8* data = mask.bits();
+        int modulo = maskWidth%4;
+        int paddingBytes = 0;
+        if (modulo>0) {
+          paddingBytes = 4-modulo;
+          for (int i = 0; i < maskHeight; ++i) {
+            data += maskWidth;
+            for (int j = 0;j<paddingBytes;j++) {
+              *data++ = 0x00;
+            }
+          }
         }
-
-        if (ctx->d_ptr->workaround_brokenAlphaTexSubImage) {
-            for (int i = 0; i < maskHeight; ++i)
-                glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y + i, maskWidth, 1, GL_ALPHA, GL_UNSIGNED_BYTE, mask.scanLine(i));
-        } else {
-            glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth, maskHeight, GL_ALPHA, GL_UNSIGNED_BYTE, mask.bits());
-        }
+        // upload the mask with a glyph width that is the next multiple of 4
+        glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth + paddingBytes, maskHeight, GL_ALPHA, GL_UNSIGNED_BYTE, mask.bits());
     }
 }