From: Yaowu Xu <yaowu@google.com>
Date: Fri, 20 May 2016 14:55:08 +0000 (-0700)
Subject: Convert to int before adding negative numbers
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8706182376f193ca8a81a479f7ac559c3b0df688;p=libvpx

Convert to int before adding negative numbers

This is avoid that -1 overflows uint32_t.

cherry-picked #c48106da from aom/master

Change-Id: Ic3d99b1985cdb0a28cc83f8291422f5aba5a5a6d
---

diff --git a/av1/encoder/lookahead.c b/av1/encoder/lookahead.c
index d00543877..f5a0aa5a9 100644
--- a/av1/encoder/lookahead.c
+++ b/av1/encoder/lookahead.c
@@ -213,8 +213,8 @@ struct lookahead_entry *av1_lookahead_peek(struct lookahead_ctx *ctx,
   } else if (index < 0) {
     // Backward peek
     if (-index <= MAX_PRE_FRAMES) {
-      index += ctx->read_idx;
-      if (index < 0) index += ctx->max_sz;
+      index += (int)(ctx->read_idx);
+      if (index < 0) index += (int)(ctx->max_sz);
       buf = ctx->buf + index;
     }
   }