From cd0663456f82b6d771e6aed01c6c4ff7f1bf4358 Mon Sep 17 00:00:00 2001
From: Cyan4973 <cyan@fb.com>
Date: Mon, 23 Apr 2018 15:47:08 -0700
Subject: [PATCH] disable shortcut for LZ4_decompress_fast()

improving speed
---
 lib/lz4.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/lib/lz4.c b/lib/lz4.c
index 40b2229..d794c35 100644
--- a/lib/lz4.c
+++ b/lib/lz4.c
@@ -1536,9 +1536,10 @@ LZ4_FORCE_INLINE int LZ4_decompress_generic(
          * this shortcut was tested on x86 and x64, where it improves decoding speed.
          * it has not yet been benchmarked on ARM, Power, mips, etc.
          * NOTE: The loop begins with a read, so we must have one byte left at the end. */
-        if (((ip + 14 /*maxLL*/ + 2 /*offset*/ < iend)
-          & (op + 14 /*maxLL*/ + 18 /*maxML*/ <= oend))
-          & ((token < (15<<ML_BITS)) & ((token & ML_MASK) != 15)) ) {
+        if (endOnInput
+          && ((ip + 14 /*maxLL*/ + 2 /*offset*/ < iend)
+            & (op + 14 /*maxLL*/ + 18 /*maxML*/ <= oend))
+            & ((token < (15<<ML_BITS)) & ((token & ML_MASK) != 15)) ) {
             size_t const ll = token >> ML_BITS;
             size_t const off = LZ4_readLE16(ip+ll);
             const BYTE* const matchPtr = op + ll - off;  /* pointer underflow risk ? */
-- 
2.7.4