OPENGL: Properly query for OpenGL errors.

There might be various error flags and we need to clear all of them to get
precise error results. Thus, we need to call glGetError in a loop to achieve
that.

1 files changed, 2 insertions, 2 deletions

diff --git a/backends/graphics/opengl/debug.cpp b/backends/graphics/opengl/debug.cpp
index 69006bb975..d5d73fb5ec 100644
--- a/backends/graphics/opengl/debug.cpp
+++ b/backends/graphics/opengl/debug.cpp
@@ -52,9 +52,9 @@ Common::String getGLErrStr(GLenum error) {
 } // End of anonymous namespace
 
 void checkGLError(const char *expr, const char *file, int line) {
-	GLenum error = glGetError();
+	GLenum error;
 
-	if (error != GL_NO_ERROR) {
+	while ((error = glGetError()) != GL_NO_ERROR) {
 		// We cannot use error here because we do not know whether we have a
 		// working screen or not.
 		warning("GL ERROR: %s on %s (%s:%d)", getGLErrStr(error).c_str(), expr, file, line);