From: Cristy <urban-warrior@imagemagick.org>
Date: Sat, 21 Apr 2018 15:43:43 +0000 (-0400)
Subject: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=7872
X-Git-Tag: 7.0.7-29~69
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=63434c1d59a91f3494bf66a92d8ecc95f5132156;p=imagemagick

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=7872
---

diff --git a/MagickCore/fx.c b/MagickCore/fx.c
index 28b4f255b..99ef1f746 100644
--- a/MagickCore/fx.c
+++ b/MagickCore/fx.c
@@ -2547,7 +2547,10 @@ static double FxEvaluateSubexpression(FxInfo *fx_info,
               case AlphaPixelChannel: type="opacity"; break;
               default: type="unknown"; break;
             }
-          (void) CopyMagickString(subexpression,expression+6,MagickPathExtent);
+          *subexpression='\0';
+          if (strlen(expression) > 6)
+            (void) CopyMagickString(subexpression,expression+6,
+              MagickPathExtent);
           if (strlen(subexpression) > 1)
             subexpression[strlen(subexpression)-1]='\0';
           if (fx_info->file != (FILE *) NULL)