From 21ca32717faef7f9753a9443c2da47e32c8ad103 Mon Sep 17 00:00:00 2001
From: "Philip.Hazel" <Philip.Hazel@gmail.com>
Date: Sun, 28 Feb 2016 13:33:55 +0000
Subject: [PATCH] Further small fix to regerror() overflow handling, to ensure
 identical output whether or not there is a zero at the end of the buffer.

---
 src/pcre2test.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/pcre2test.c b/src/pcre2test.c
index 2ccde8c..100e1d2 100644
--- a/src/pcre2test.c
+++ b/src/pcre2test.c
@@ -4779,8 +4779,12 @@ if ((pat_patctl.control & CTL_POSIX) != 0)
     if (bsize + 8 < pbuffer8_size)
       memcpy(pbuffer8 + bsize, "DEADBEEF", 8);
     usize = regerror(rc, &preg, (char *)pbuffer8, bsize);
+    
+    /* Inside regerror(), snprintf() is used. If the buffer is too small, some 
+    versions of snprintf() put a zero byte at the end, but others do not. 
+    Therefore, we print a maximum of one less than the size of the buffer. */
 
-    psize = (int)bsize;
+    psize = (int)bsize - 1;
     fprintf(outfile, "Failed: POSIX code %d: %.*s\n", rc, psize, pbuffer8);
     if (usize > bsize)
       {