OpenGL: Don't request a context version higher than is supported

The function wglCreateContextAttribsARB will fail if we request a
context version higher than is supported. We therefore upper-bound the
requested version by the version of the static context. This results
in context creation succeeding and having the closest possible match
to the requested format.

The xcb qpa plugin is modified to operate similarly to the windows
plugin in that it now creates a "static" context which is used to
limit the versions of contexts requested by the user.

Change-Id: I277ad7cc82edfdf7b9d8502ad921c8175feb1a4a
Reviewed-by: Samuel Rødal <samuel.rodal@digia.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/src/gui/kernel/qplatformopenglcontext.cpp b/src/gui/kernel/qplatformopenglcontext.cpp
index 8e6a9da562..f2d6f6199c 100644
--- a/src/gui/kernel/qplatformopenglcontext.cpp
+++ b/src/gui/kernel/qplatformopenglcontext.cpp
@@ -118,14 +118,14 @@ void QPlatformOpenGLContext::setContext(QOpenGLContext *context)
     d->context = context;
 }
 
-bool QPlatformOpenGLContext::parseOpenGLVersion(const QString& versionString, int &major, int &minor)
+bool QPlatformOpenGLContext::parseOpenGLVersion(const QByteArray &versionString, int &major, int &minor)
 {
     bool majorOk = false;
     bool minorOk = false;
-    QStringList parts = versionString.split(QLatin1Char(' '));
-    if (versionString.startsWith(QLatin1String("OpenGL ES"))) {
+    QList<QByteArray> parts = versionString.split(' ');
+    if (versionString.startsWith(QByteArrayLiteral("OpenGL ES"))) {
         if (parts.size() >= 3) {
-            QStringList versionParts = parts.at(2).split(QLatin1Char('.'));
+            QList<QByteArray> versionParts = parts.at(2).split('.');
             if (versionParts.size() >= 2) {
                 major = versionParts.at(0).toInt(&majorOk);
                 minor = versionParts.at(1).toInt(&minorOk);
@@ -138,7 +138,7 @@ bool QPlatformOpenGLContext::parseOpenGLVersion(const QString& versionString, in
         }
     } else {
         // Not OpenGL ES, but regular OpenGL, the version numbers are first in the string
-        QStringList versionParts = parts.at(0).split(QLatin1Char('.'));
+        QList<QByteArray> versionParts = parts.at(0).split('.');
         if (versionParts.size() >= 2) {
             major = versionParts.at(0).toInt(&majorOk);
             minor = versionParts.at(1).toInt(&minorOk);