From: Jim Meyering <jim@meyering.net>
Date: Wed, 21 Jun 2000 12:56:33 +0000 (+0000)
Subject: (path_concat): Don't access dir[-1] if dir is the empty string.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8d447ad210177980a4747a2208a00d001fc7ccee;p=pspp

(path_concat): Don't access dir[-1] if dir is the empty string.
---

diff --git a/lib/path-concat.c b/lib/path-concat.c
index 8c4bbb4e8b..d6dafc9398 100644
--- a/lib/path-concat.c
+++ b/lib/path-concat.c
@@ -86,10 +86,13 @@ path_concat (const char *dir, const char *base, char **base_in_result)
 
   p = mempcpy (p_concat, dir, dir_len);
 
-  if (ISSLASH (*(p - 1)) && ISSLASH(*base))
-    --p;
-  else if (!ISSLASH (*(p - 1)) && !ISSLASH(*base))
-    *p++ = DIRECTORY_SEPARATOR;
+  if (dir_len > 0)
+    {
+      if (ISSLASH (*(p - 1)) && ISSLASH(*base))
+	--p;
+      else if (!ISSLASH (*(p - 1)) && !ISSLASH(*base))
+	*p++ = DIRECTORY_SEPARATOR;
+    }
 
   if (base_in_result)
     *base_in_result = p;