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

2 files changed, 15 insertions, 1 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();
diff --git a/vcl/source/opengl/OpenGLHelper.cxx b/vcl/source/opengl/OpenGLHelper.cxx
index 6019850c88fe..62cb91887d4e 100644
--- a/vcl/source/opengl/OpenGLHelper.cxx
+++ b/vcl/source/opengl/OpenGLHelper.cxx
@@ -694,7 +694,7 @@ void OpenGLHelper::debugMsgPrint(const char *pArea, const char *pFormat, ...)
     vsnprintf(pStr, sizeof(pStr), pFormat, aArgs);
     pStr[sizeof(pStr)-20] = '\0';
 
-    bool bHasContext = !OpenGLContext::hasCurrent();
+    bool bHasContext = OpenGLContext::hasCurrent();
     if (!bHasContext)
         strcat(pStr, "- no GL context");