st/wgl: fix WGL_SWAP_METHOD_ARB query

There are three possible return values (not two): WGL_SWAP_COPY_ARB,
WGL_SWAP_EXCHANGE_EXT and WGL_SWAP_UNDEFINED_ARB.

VMware bug 1431184

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
Reviewed-by: Charmaine Lee <charmainel@vmware.com>

diff --git a/src/gallium/state_trackers/wgl/stw_ext_pixelformat.c b/src/gallium/state_trackers/wgl/stw_ext_pixelformat.c
index 9f466ba..e38086e 100644 (file)
--- a/src/gallium/state_trackers/wgl/stw_ext_pixelformat.c
+++ b/src/gallium/state_trackers/wgl/stw_ext_pixelformat.c
@@ -88,7 +88,12 @@ stw_query_attrib(
       return TRUE;
 
    case WGL_SWAP_METHOD_ARB:
-      *pvalue = pfi->pfd.dwFlags & PFD_SWAP_COPY ? WGL_SWAP_COPY_ARB : WGL_SWAP_UNDEFINED_ARB;
+      if (pfi->pfd.dwFlags & PFD_SWAP_COPY)
+         *pvalue = WGL_SWAP_COPY_ARB;
+      else if (pfi->pfd.dwFlags & PFD_SWAP_EXCHANGE)
+         *pvalue = WGL_SWAP_EXCHANGE_EXT;
+      else
+         *pvalue = WGL_SWAP_UNDEFINED_ARB;
       return TRUE;
 
    case WGL_SWAP_LAYER_BUFFERS_ARB: