From: Dirk Lemstra <dirk@lemstra.org>
Date: Fri, 23 Aug 2019 15:39:43 +0000 (+0200)
Subject: Corrected offset for header #1676.
X-Git-Tag: 7.0.8-62~2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=cee9e9439df34239875b3c0e5f2116ba2007ec02;p=imagemagick

Corrected offset for header #1676.
---

diff --git a/coders/jp2.c b/coders/jp2.c
index 63030715a..ca887d056 100644
--- a/coders/jp2.c
+++ b/coders/jp2.c
@@ -147,9 +147,9 @@ static MagickBooleanType IsJP2(const unsigned char *magick,const size_t length)
     return(MagickFalse);
   if (memcmp(magick,"\x0d\x0a\x87\x0a",4) == 0)
     return(MagickTrue);
-  if (length < 12)
+  if (length < 16)
     return(MagickFalse);
-  if (memcmp(magick,"\x00\x00\x00\x0c\x6a\x50\x20\x20\x0d\x0a\x87\x0a",12) == 0)
+  if (memcmp(magick+4,"\x00\x00\x00\x0c\x6a\x50\x20\x20\x0d\x0a\x87\x0a",12) == 0)
     return(MagickTrue);
   return(MagickFalse);
 }
diff --git a/coders/jp2.h b/coders/jp2.h
index fc45935a2..84521b6dc 100644
--- a/coders/jp2.h
+++ b/coders/jp2.h
@@ -17,7 +17,7 @@
 #include "coders/coders-private.h"
 
 #define MagickJP2Headers \
-  MagickCoderHeader("JP2", 0, "\x00\x00\x00\x0c\x6a\x50\x20\x20\x0d\x0a\x87\x0a") \
+  MagickCoderHeader("JP2", 4, "\x00\x00\x00\x0c\x6a\x50\x20\x20\x0d\x0a\x87\x0a") \
   MagickCoderHeader("JPC", 0, "\x0d\x0a\x87\x0a") \
   MagickCoderHeader("J2K", 0, "\xff\x4f\xff\x51")