Add check for old being NULL in utmp_setid(); from Steven McDonald

diff --git a/src/utmp.c b/src/utmp.c
index befbaf6f2cbddac893e615779a3ae74d4f38c396..e3d711bee1cdc41b53ec05a2f6cb65bbeeaedc18 100644 (file)
--- a/src/utmp.c
+++ b/src/utmp.c
@@ -96,10 +96,12 @@ utmp_setid(sudo_utmp_t *old, sudo_utmp_t *new)
     size_t idlen;
 
     /* Skip over "tty" in the id if old entry did too. */
-    if (strncmp(line, "tty", 3) == 0) {
-       idlen = MIN(sizeof(old->ut_id), 3);
-       if (strncmp(old->ut_id, "tty", idlen) != 0)
-           line += 3;
+    if (old != NULL) {
+       if (strncmp(line, "tty", 3) == 0) {
+           idlen = MIN(sizeof(old->ut_id), 3);
+           if (strncmp(old->ut_id, "tty", idlen) != 0)
+               line += 3;
+       }
     }
     
     /* Store as much as will fit, skipping parts of the beginning as needed. */