From 06eb92b87e750fd7a14312b15b09f2c168e4ed4c Mon Sep 17 00:00:00 2001
From: Michal Simon <michal.simon@cern.ch>
Date: Fri, 17 Jan 2020 16:39:17 +0100
Subject: [PATCH] [XrdOuc] Prevent seqv in XrdOucString::replace().

fixes #1094
---
 src/XrdOuc/XrdOucString.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/XrdOuc/XrdOucString.cc b/src/XrdOuc/XrdOucString.cc
index 7eb2ce9200c..3ec006384a7 100644
--- a/src/XrdOuc/XrdOucString.cc
+++ b/src/XrdOuc/XrdOucString.cc
@@ -808,7 +808,8 @@ int XrdOucString::replace(const char *s1, const char *s2, int from, int to)
                memcpy(pc-l2,s2,l2);
             nc--;
             atn = at;
-            at = rfind(s1,at-l1);
+            if( at - l1 < 0 ) at = -1;
+            else at = rfind(s1,at-l1);
          }
          dl = nr*dd;
       }