shithub: libvpx

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Fixing undefined behavior vp9_peek_si().

Bitwise OR operation doesn't guarantee any subexpression evaluation order.
Just reading one bit now and ignoring the next one. For reference look at
vp9_decode_frame() implementation.

Change-Id: I4971686929838ae5ded8f43a38a2934db5e1d462

--- a/vp9/vp9_dx_iface.c

+++ b/vp9/vp9_dx_iface.c

@@ -148,7 +148,9 @@

   {

     struct vp9_read_bit_buffer rb = { data, data + data_sz, 0, NULL, NULL };

     const int frame_marker = vp9_rb_read_literal(&rb, 2);

-    const int version = vp9_rb_read_bit(&rb) | (vp9_rb_read_bit(&rb) << 1);

+    const int version = vp9_rb_read_bit(&rb);

+    (void) vp9_rb_read_bit(&rb);  // unused version bit

+

     if (frame_marker != VP9_FRAME_MARKER)

       return VPX_CODEC_UNSUP_BITSTREAM;

 #if CONFIG_NON420