From 21cb19455c08555431eb7b4a942df6a9f64c0941 Mon Sep 17 00:00:00 2001
From: Martin Storsjo <martin@martin.st>
Date: Wed, 7 Jun 2017 16:17:59 +0300
Subject: [PATCH] Don't try to read a negative number of bits

Fixes: 1919/clusterfuzz-testcase-minimized-5021082513833984

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
---
 libSBRdec/src/psbitdec.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libSBRdec/src/psbitdec.cpp b/libSBRdec/src/psbitdec.cpp
index 29bddf7..ec6e484 100644
--- a/libSBRdec/src/psbitdec.cpp
+++ b/libSBRdec/src/psbitdec.cpp
@@ -498,7 +498,7 @@ ReadPsData (HANDLE_PS_DEC h_ps_d,          /*!< handle to struct PS_DEC */
     h_ps_d->bPsDataAvail[h_ps_d->bsReadSlot] = ppt_none;
     /* discard all remaining bits */
     nBitsLeft -= startbits - FDKgetValidBits(hBitBuf);
-    while (nBitsLeft) {
+    while (nBitsLeft > 0) {
       int i = nBitsLeft;
       if (i>8) {
         i = 8;