From 3c1aba15b52f3c92a9530f0321169d86979b4b56 Mon Sep 17 00:00:00 2001
From: YannisGuyon <7632072+YannisGuyon@users.noreply.github.com>
Date: Mon, 8 Oct 2018 19:08:49 +0200
Subject: [PATCH]  [libwebp] webp_enc_dec: Limit alpha_quality to 99 when
 method is 6 (#1860)

webp_enc_dec: Limit alpha_quality to 99 when method is 6

The target fuzz_webp_enc_dec with asan crashes (timeout)
during encoding with heavy alpha compression.
Clamp alpha compression parameters for images bigger than 16*16.
Bug report 10838
---
 projects/libwebp/fuzz_webp_enc_dec.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/projects/libwebp/fuzz_webp_enc_dec.cc b/projects/libwebp/fuzz_webp_enc_dec.cc
index 84726eac3..c1830e5d1 100644
--- a/projects/libwebp/fuzz_webp_enc_dec.cc
+++ b/projects/libwebp/fuzz_webp_enc_dec.cc
@@ -193,6 +193,9 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* const data, size_t size) {
         config.quality = 99.0f;
       }
     }
+    if (config.alpha_quality == 100 && config.method == 6) {
+      config.alpha_quality = 99;
+    }
   }
 
   // Encode.