[FFmpeg-cvslog] avcodec/exr: Fix undefined left shifts of negative numbers

[Andreas Rheinhardt]

ffmpeg | branch: release/3.4 | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Wed Sep 25 00:03:07 2019 +0200| [00d98fa0579657ebc1b56f3d290489724c430d28] | committer: Andreas Rheinhardt

avcodec/exr: Fix undefined left shifts of negative numbers

Affected the FATE-tests exr-rgb-scanline-pxr24-half-uint32-13x9 and
exr-rgb-scanline-pxr24-uint32.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 8b0f949906116c40b6f1e55a1bce4447ada3219c)
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=00d98fa0579657ebc1b56f3d290489724c430d28
---

 libavcodec/exr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index 7c3e3dc6f6..89966a8b61 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -881,7 +881,7 @@ static int pxr24_uncompress(EXRContext *s, const uint8_t *src,
                 in     = ptr[3] + s->xdelta;
 
                 for (j = 0; j < s->xdelta; ++j) {
-                    uint32_t diff = (*(ptr[0]++) << 24) |
+                    uint32_t diff = ((uint32_t)*(ptr[0]++) << 24) |
                     (*(ptr[1]++) << 16) |
                     (*(ptr[2]++) << 8 ) |
                     (*(ptr[3]++));