vdpau: fix uninit when init fails

The uninit() function was called twice if the uninit() function failed
(once by init(), once by vd_lavc.c code), which caused crashes due to
double-free. (This failure is a corner case, and all other hwdec
backends appear to handle this case gracefully.)

I do not think this code should be able to deal with uninit() being
called other than once. Guarantee that it's called exactly once.

2 files changed, 2 insertions, 5 deletions

diff --git a/video/decode/vd_lavc.c b/video/decode/vd_lavc.c
index cdd0dd8884..9ce657bb5c 100644
--- a/video/decode/vd_lavc.c
+++ b/video/decode/vd_lavc.c
@@ -456,6 +456,7 @@ static void uninit_avctx(struct dec_video *vd)
 
     if (ctx->hwdec && ctx->hwdec->uninit)
         ctx->hwdec->uninit(ctx);
+    ctx->hwdec = NULL;
 
     av_freep(&ctx->avctx);
 
diff --git a/video/decode/vdpau.c b/video/decode/vdpau.c
index 9a3e7e27cf..f8375532fb 100644
--- a/video/decode/vdpau.c
+++ b/video/decode/vdpau.c
@@ -80,13 +80,9 @@ static int init(struct lavc_ctx *ctx)
     ctx->hwdec_priv = p;
 
     if (mp_vdpau_handle_preemption(p->mpvdp, &p->preemption_counter) < 1)
-        goto error;
+        return -1;
 
     return 0;
-
-error:
-    uninit(ctx);
-    return -1;
 }
 
 static int probe(struct vd_lavc_hwdec *hwdec, struct mp_hwdec_info *info,