1 files changed, 4 insertions, 5 deletions

diff --git a/libbb/update_passwd.c b/libbb/update_passwd.c
index dc26ebd1d..a2004f480 100644
--- a/libbb/update_passwd.c
+++ b/libbb/update_passwd.c
@@ -84,7 +84,6 @@ int FAST_FUNC update_passwd(const char *filename,
         char *fnamesfx;
         char *sfx_char;
         char *name_colon;
-        unsigned user_len;
         int old_fd;
         int new_fd;
         int i;
@@ -108,7 +107,6 @@ int FAST_FUNC update_passwd(const char *filename,
         fnamesfx = xasprintf("%s+", filename);
         sfx_char = &fnamesfx[strlen(fnamesfx)-1];
         name_colon = xasprintf("%s:", name ? name : "");
-        user_len = strlen(name_colon);
 
         if (shadow)
                 old_fp = fopen(filename, "r+");
@@ -179,7 +177,7 @@ int FAST_FUNC update_passwd(const char *filename,
                         while (list) {
                                 list++;
  next_list_element:
-                                if (strncmp(list, member, member_len) == 0) {
+                                if (is_prefixed_with(list, member)) {
                                         char c;
                                         changed_lines++;
                                         c = list[member_len];
@@ -201,13 +199,14 @@ int FAST_FUNC update_passwd(const char *filename,
                         goto next;
                 }
 
-                if (strncmp(name_colon, line, user_len) != 0) {
+                cp = is_prefixed_with(line, name_colon);
+                if (!cp) {
                         fprintf(new_fp, "%s\n", line);
                         goto next;
                 }
 
                 /* We have a match with "name:"... */
-                cp = line + user_len; /* move past name: */
+                /* cp points past "name:" */
 
 #if ENABLE_FEATURE_ADDUSER_TO_GROUP || ENABLE_FEATURE_DEL_USER_FROM_GROUP
                 if (member) {