tdf#93867 - clear current GL context before thread switch.

Fixes regression from otherwise a nice cleanup in:
d20092259c7ea63885a539f911788715f8147ee9

Also get polarity of debug logging only with a context right.

Change-Id: Id322471f01e5656e758aefc57b0d4d5ad073ec54

1 files changed, 14 insertions, 0 deletions

diff --git a/vcl/source/opengl/OpenGLContext.cxx b/vcl/source/opengl/OpenGLContext.cxx
index 49feb75368b4..3c305d523d98 100644
--- a/vcl/source/opengl/OpenGLContext.cxx
+++ b/vcl/source/opengl/OpenGLContext.cxx
@@ -1336,6 +1336,20 @@ void OpenGLContext::clearCurrent()
         pCurrentCtx->ReleaseFramebuffers();
 }
 
+void OpenGLContext::prepareForYield()
+{
+    ImplSVData* pSVData = ImplGetSVData();
+
+    SAL_INFO("vcl.opengl", "Unbinding contexts in preparation for yield");
+    // release all framebuffers from the old context so we can re-attach the
+    // texture in the new context
+    OpenGLContext* pCurrentCtx = pSVData->maGDIData.mpLastContext;
+    if( pCurrentCtx && pCurrentCtx->isCurrent() )
+        pCurrentCtx->resetCurrent();
+
+    assert (!hasCurrent());
+}
+
 void OpenGLContext::makeCurrent()
 {
     ImplSVData* pSVData = ImplGetSVData();