3 files changed, 24 insertions, 2 deletions

diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
index 1dcb773..73915cb 100644
--- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
+++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp
@@ -1479,6 +1479,8 @@ void QGL2PaintEngineExPrivate::drawCachedGlyphs(QFontEngineGlyphCache::Type glyp
     if (!cache || cache->cacheType() != glyphType) {
         cache = new QGLTextureGlyphCache(ctx, glyphType, QTransform());
         staticTextItem->fontEngine()->setGlyphCache(ctx, cache);
+    } else if (cache->context() == 0) { // Old context has been destroyed, new context has same ptr value
+        cache->setContext(ctx);
     }
 
     bool recreateVertexArrays = false;
diff --git a/src/opengl/gl2paintengineex/qtextureglyphcache_gl.cpp b/src/opengl/gl2paintengineex/qtextureglyphcache_gl.cpp
index 919c542..28e8c40 100644
--- a/src/opengl/gl2paintengineex/qtextureglyphcache_gl.cpp
+++ b/src/opengl/gl2paintengineex/qtextureglyphcache_gl.cpp
@@ -54,11 +54,18 @@ extern Q_GUI_EXPORT bool qt_cleartype_enabled;
 
 QGLTextureGlyphCache::QGLTextureGlyphCache(QGLContext *context, QFontEngineGlyphCache::Type type, const QTransform &matrix)
     : QImageTextureGlyphCache(type, matrix)
-    , ctx(context)
+    , ctx(0)
     , m_width(0)
     , m_height(0)
     , m_filterMode(Nearest)
 {
+    setContext(context);
+}
+
+void QGLTextureGlyphCache::setContext(QGLContext *context)
+{
+    ctx = context;
+
     // broken FBO readback is a bug in the SGX 1.3 and 1.4 drivers for the N900 where
     // copying between FBO's is broken if the texture is either GL_ALPHA or POT. The
     // workaround is to use a system-memory copy of the glyph cache for this device.
diff --git a/src/opengl/gl2paintengineex/qtextureglyphcache_gl_p.h b/src/opengl/gl2paintengineex/qtextureglyphcache_gl_p.h
index e22146d..fa2b091 100644
--- a/src/opengl/gl2paintengineex/qtextureglyphcache_gl_p.h
+++ b/src/opengl/gl2paintengineex/qtextureglyphcache_gl_p.h
@@ -90,6 +90,9 @@ public:
     FilterMode filterMode() const { return m_filterMode; }
     void setFilterMode(FilterMode m) { m_filterMode = m; }
 
+    void setContext(QGLContext *context);
+    QGLContext *context() const { return ctx; }
+
 public Q_SLOTS:
     void contextDestroyed(const QGLContext *context) {
         if (context == ctx) {
@@ -98,10 +101,20 @@ public Q_SLOTS:
                 // the context may not be current, so we cannot directly
                 // destroy the fbo and texture here, but since the context
                 // is about to be destroyed, the GL server will do the
-                // clean up for us anyway
+                // clean up for us anyway. We reset everything, so that the
+                // glyph cache object can be reused later by setting a new
+                // context on it.
                 m_fbo = 0;
                 m_texture = 0;
                 ctx = 0;
+                m_width = 0;
+                m_height = 0;
+                m_w = 0;
+                m_h = 0;
+                m_cx = 0;
+                m_cy = 0;
+                m_currentRowHeight = 0;
+                coords.clear();
             } else {
                 // since the context holding the texture is shared, and
                 // about to be destroyed, we have to transfer ownership