[PATCH] winegstreamer: Read into an existing buffer if requested.

[Zebediah Figura]

From: Zebediah Figura <zfigura(a)codeweavers.com>

oggdemux needs this.

Signed-off-by: Zebediah Figura <zfigura(a)codeweavers.com>
---
 dlls/winegstreamer/gstdemux.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/dlls/winegstreamer/gstdemux.c b/dlls/winegstreamer/gstdemux.c
index a51354b13c..e9548e80e4 100644
--- a/dlls/winegstreamer/gstdemux.c
+++ b/dlls/winegstreamer/gstdemux.c
@@ -896,9 +896,8 @@ static GstFlowReturn request_buffer_src(GstPad *pad, GstObject *parent, guint64
     HRESULT hr;
     GstMapInfo info;
 
-    TRACE("%p %s %i %p\n", pad, wine_dbgstr_longlong(ofs), len, buf);
+    TRACE("pad %p, offset %s, length %u, buffer %p.\n", pad, wine_dbgstr_longlong(ofs), len, *buf);
 
-    *buf = NULL;
     if (ofs == GST_BUFFER_OFFSET_NONE)
         ofs = This->nextpullofs;
     if (ofs >= This->filesize) {
@@ -909,7 +908,8 @@ static GstFlowReturn request_buffer_src(GstPad *pad, GstObject *parent, guint64
         len = This->filesize - ofs;
     This->nextpullofs = ofs + len;
 
-    *buf = gst_buffer_new_and_alloc(len);
+    if (!*buf)
+        *buf = gst_buffer_new_and_alloc(len);
     gst_buffer_map(*buf, &info, GST_MAP_WRITE);
     hr = IAsyncReader_SyncRead(This->reader, ofs, len, info.data);
     gst_buffer_unmap(*buf, &info);
-- 
2.25.1