env: prefer xpalloc to xrealloc

* src/env.c (extract_varname): Prefer free+xpalloc to
xrealloc, since the old buffer contents don’t matter.

diff --git a/src/env.c b/src/env.c
index 45c94ed092afaf9a8272e1136b695e56c745da95..48c6b3909797af1c7a94673565693f8f7aaf969f 100644 (file)
--- a/src/env.c
+++ b/src/env.c
@@ -229,8 +229,8 @@ extract_varname (char const *str)
 
   if (i >= vnlen)
     {
-      vnlen = i + 1;
-      varname = xrealloc (varname, vnlen);
+      free (varname);
+      varname = xpalloc (nullptr, &vnlen, i + 1 - vnlen, -1, sizeof *varname);
     }
 
   memcpy (varname, str + 2, i);