* strings.h (strechr): New function.

* uinfo.cc (pwdgrp::next_str): Search only for input char in string.  Return
EOS on failure.  Don't check for NULL since it shouldn't be possible.
(pwdgrp::add_line): Revert to replacing '\n' in input line with '\0'.
(pwdgrp::next_num): Pass explicit separator character to next_str.
* grp.cc (pwdgrp::parse_group): Ditto.
* passwd.cc (pwdgrp::parse_passwd): Ditto.  Revamp test for garbage input.
* pwdgrp.h (pwdgrp::next_str): Don't use default parameter.

winsup/cygwin/grp.cc

@@ -37,11 +37,11 @@ bool
 pwdgrp::parse_group ()
 {
 # define grp (*group_buf)[curr_lines]
-  grp.gr_name = next_str ();
+  grp.gr_name = next_str (':');
   if (!*grp.gr_name)
     return false;
 
-  grp.gr_passwd = next_str ();
+  grp.gr_passwd = next_str (':');
 
   if (!next_num (grp.gr_gid))
     return false;