Rico Schüller : wined3d: Don' t allow a negative lock_count in buffer_Unmap.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 3ea66d6026a208f5fc551cd9a5bb421d2adfa4e3
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=3ea66d6026a208f5fc551cd9a5bb421d2adfa4e3

Author: Rico Schüller <kgbricola at web.de>
Date:   Wed Jun 10 21:54:07 2009 +0200

wined3d: Don't allow a negative lock_count in buffer_Unmap.

---

 dlls/wined3d/buffer.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/dlls/wined3d/buffer.c b/dlls/wined3d/buffer.c
index 666de8e..e9f3ff6 100644
--- a/dlls/wined3d/buffer.c
+++ b/dlls/wined3d/buffer.c
@@ -985,6 +985,16 @@ static HRESULT STDMETHODCALLTYPE buffer_Unmap(IWineD3DBuffer *iface)
 
     TRACE("(%p)\n", This);
 
+    /* In the case that the number of Unmap calls > the
+     * number of Map calls, d3d returns always D3D_OK.
+     * This is also needed to prevent Map from returning garbage on
+     * the next call (this will happen if the lock_count is < 0). */
+    if(This->lock_count == 0)
+    {
+        TRACE("Unmap called without a previous Map call!\n");
+        return WINED3D_OK;
+    }
+
     if (InterlockedDecrement(&This->lock_count))
     {
         /* Delay loading the buffer until everything is unlocked */