desktop-main.cpp: don't validate for custom backends

Without this patch the user can pass a custom backend
like 'software' and the validation will still be performed.
In a case where the validation fails Subsurface will still exit.

With this patch the validation is performed *only* for the
standard backend which is OpenGL (or an empty QT_QUICK_BACKEND)
env. variable.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/subsurface-desktop-main.cpp b/subsurface-desktop-main.cpp
index d0b764e7b..e8f57ecff 100644
--- a/subsurface-desktop-main.cpp
+++ b/subsurface-desktop-main.cpp
@@ -140,6 +140,18 @@ bool haveFilesOnCommandLine()
 
 void validateGL()
 {
+	QString quickBackend = qgetenv("QT_QUICK_BACKEND");
+	/* an empty QT_QUICK_BACKEND env. variable means OpenGL (default).
+	 * only validate OpenGL; for everything else print out and return.
+	 * https://doc.qt.io/qt-5/qtquick-visualcanvas-adaptations.html
+	 */
+	if (!quickBackend.isEmpty()) {
+		if (verbose) {
+			qDebug() << QStringLiteral(VALIDATE_GL_PREFIX "'QT_QUICK_BACKEND' is set to '%1'. "
+				"Skipping validation.").arg(quickBackend).toUtf8().data();
+		}
+		return;
+	}
 	GLint verMajor, verMinor;
 	const char *glError = NULL;
 	QOpenGLContext ctx;