Fixed querying of GLX extensions under X11.

We always queried the client for its GLX extensions and used them
blindly, even though they might not be available in the server.
Also fixed the extension string check itself. We used simple sub-string
search, which could potentially break if one extension name is a
sub-string of another.

Task-number: QTBUG-5732
Reviewed-by: Kim

1 files changed, 14 insertions, 13 deletions

diff --git a/src/opengl/qgl_x11.cpp b/src/opengl/qgl_x11.cpp
index 899047a..a037282 100644
--- a/src/opengl/qgl_x11.cpp
+++ b/src/opengl/qgl_x11.cpp
@@ -343,8 +343,8 @@ void* qglx_getProcAddress(const char* procName)
     static bool triedResolvingGlxGetProcAddress = false;
     if (!triedResolvingGlxGetProcAddress) {
         triedResolvingGlxGetProcAddress = true;
-        QString glxExt = QLatin1String(glXGetClientString(QX11Info::display(), GLX_EXTENSIONS));
-        if (glxExt.contains(QLatin1String("GLX_ARB_get_proc_address"))) {
+        QList<QByteArray> glxExt = QByteArray(glXGetClientString(QX11Info::display(), GLX_EXTENSIONS)).split(' ');
+        if (glxExt.contains("GLX_ARB_get_proc_address")) {
 #if defined(Q_OS_LINUX) || defined(Q_OS_BSD4)
             void *handle = dlopen(NULL, RTLD_LAZY);
             if (handle) {
@@ -523,8 +523,8 @@ bool QGLContext::chooseContext(const QGLContext* shareContext)
         if (!d->gpm)
             return false;
     }
-    QString glxExt = QLatin1String(glXGetClientString(QX11Info::display(), GLX_EXTENSIONS));
-    if (glxExt.contains(QLatin1String("GLX_SGI_video_sync"))) {
+    QList<QByteArray> glxExt = QByteArray(glXQueryExtensionsString(xinfo->display(), xinfo->screen())).split(' ');
+    if (glxExt.contains("GLX_SGI_video_sync")) {
         if (d->glFormat.swapInterval() == -1)
             d->glFormat.setSwapInterval(0);
     } else {
@@ -874,8 +874,9 @@ void QGLContext::swapBuffers() const
             static qt_glXWaitVideoSyncSGI glXWaitVideoSyncSGI = 0;
             static bool resolved = false;
             if (!resolved) {
-                QString glxExt = QLatin1String(glXGetClientString(QX11Info::display(), GLX_EXTENSIONS));
-                if (glxExt.contains(QLatin1String("GLX_SGI_video_sync"))) {
+                const QX11Info *xinfo = qt_x11Info(d->paintDevice);
+                QList<QByteArray> glxExt = QByteArray(glXQueryExtensionsString(xinfo->display(), xinfo->screen())).split(' ');
+                if (glxExt.contains("GLX_SGI_video_sync")) {
                     glXGetVideoSyncSGI =  (qt_glXGetVideoSyncSGI)qglx_getProcAddress("glXGetVideoSyncSGI");
                     glXWaitVideoSyncSGI = (qt_glXWaitVideoSyncSGI)qglx_getProcAddress("glXWaitVideoSyncSGI");
                 }
@@ -1106,8 +1107,8 @@ void *QGLContext::getProcAddress(const QString &proc) const
     if (resolved && !glXGetProcAddressARB)
         return 0;
     if (!glXGetProcAddressARB) {
-        QString glxExt = QLatin1String(glXGetClientString(QX11Info::display(), GLX_EXTENSIONS));
-        if (glxExt.contains(QLatin1String("GLX_ARB_get_proc_address"))) {
+        QList<QByteArray> glxExt = QByteArray(glXGetClientString(QX11Info::display(), GLX_EXTENSIONS)).split(' ');
+        if (glxExt.contains("GLX_ARB_get_proc_address")) {
 #if defined(Q_OS_LINUX) || defined(Q_OS_BSD4)
             void *handle = dlopen(NULL, RTLD_LAZY);
             if (handle) {
@@ -1594,7 +1595,7 @@ typedef void (*qt_glXReleaseTexImageEXT)(Display*, GLXDrawable, int);
 static qt_glXBindTexImageEXT glXBindTexImageEXT = 0;
 static qt_glXReleaseTexImageEXT glXReleaseTexImageEXT = 0;
 
-bool qt_resolveTextureFromPixmap()
+static bool qt_resolveTextureFromPixmap(QPaintDevice *paintDevice)
 {
     static bool resolvedTextureFromPixmap = false;
 
@@ -1607,9 +1608,9 @@ bool qt_resolveTextureFromPixmap()
         {
             return false; // Can't use TFP without NPOT
         }
-
-        QString glxExt = QLatin1String(glXGetClientString(QX11Info::display(), GLX_EXTENSIONS));
-        if (glxExt.contains(QLatin1String("GLX_EXT_texture_from_pixmap"))) {
+        const QX11Info *xinfo = qt_x11Info(paintDevice);
+        QList<QByteArray> glxExt = QByteArray(glXQueryExtensionsString(xinfo->display(), xinfo->screen())).split(' ');
+        if (glxExt.contains("GLX_EXT_texture_from_pixmap")) {
             glXBindTexImageEXT = (qt_glXBindTexImageEXT) qglx_getProcAddress("glXBindTexImageEXT");
             glXReleaseTexImageEXT = (qt_glXReleaseTexImageEXT) qglx_getProcAddress("glXReleaseTexImageEXT");
         }
@@ -1630,7 +1631,7 @@ QGLTexture *QGLContextPrivate::bindTextureFromNativePixmap(QPixmapData *pmd, con
 
     Q_ASSERT(pmd->classId() == QPixmapData::X11Class);
 
-    if (!qt_resolveTextureFromPixmap())
+    if (!qt_resolveTextureFromPixmap(paintDevice))
         return 0;
 
     QX11PixmapData *pixmapData = static_cast<QX11PixmapData*>(pmd);