* callproc.c (child_setup): Rewrite to avoid two strlen calls.

2 files changed, 3 insertions, 2 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index b843dfc6965..bcf40a4e470 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,7 @@
 2011-06-19  Paul Eggert  <eggert@cs.ucla.edu>
 
+        * callproc.c (child_setup): Rewrite to avoid two strlen calls.
+
         * process.c (Fformat_network_address): Use EMACS_INT, not EMACS_UINT.
         We prefer signed integers, even for size calculations.
 
diff --git a/src/callproc.c b/src/callproc.c
index fae47b7a699..12621c90db5 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -1230,8 +1230,7 @@ child_setup (int in, int out, int err, register char **new_argv, int set_pgrp, L
 
     if (STRINGP (display))
       {
-        int vlen = strlen ("DISPLAY=") + strlen (SSDATA (display)) + 1;
-        char *vdata = (char *) alloca (vlen);
+        char *vdata = (char *) alloca (sizeof "DISPLAY=" + SBYTES (display));
         strcpy (vdata, "DISPLAY=");
         strcat (vdata, SSDATA (display));
         new_env = add_env (env, new_env, vdata);