comsat: fix botched strtonum() conversion

[Todd C. Miller]

The message sent by mail.local ends in a newline so we need to trim
it before calling strtonum().  Also adds some debugging syslogs
that were useful along the way (disabled by default).

 - todd

Index: libexec/comsat/comsat.c
===================================================================
RCS file: /cvs/src/libexec/comsat/comsat.c,v
retrieving revision 1.39
diff -u -p -u -r1.39 comsat.c
--- libexec/comsat/comsat.c     18 Apr 2015 18:28:37 -0000      1.39
+++ libexec/comsat/comsat.c     6 Jul 2015 14:56:23 -0000
@@ -191,6 +191,7 @@ doreadutmp(void)
                }
                (void)lseek(uf, 0, SEEK_SET);
                nutmp = read(uf, utmp, statbf.st_size)/sizeof(struct utmp);
+               dsyslog(LOG_DEBUG, "read %d utmp entries", nutmp);
        }
        (void)alarm(15);
 }
@@ -204,15 +205,22 @@ mailfor(char *name)
        char *cp;
        off_t offset;
 
+       dsyslog(LOG_DEBUG, "mail for '%s'", name);
+       cp = name + strlen(name) - 1;
+       while (cp > name && isspace((unsigned char)*cp))
+               *cp-- = '\0';
        if (!(cp = strchr(name, '@')))
                return;
        *cp = '\0';
        offset = strtonum(cp + 1, 0, LLONG_MAX, &errstr);
-       if (errstr)
+       if (errstr) {
+               syslog(LOG_ERR, "'%s' is %s", cp + 1, errstr);
                return;
+       }
        while (--utp >= utmp) {
                memcpy(utname, utp->ut_name, UT_NAMESIZE);
                utname[UT_NAMESIZE] = '\0';
+               dsyslog(LOG_DEBUG, "check %s against %s", name, utname);
                if (!strncmp(utname, name, UT_NAMESIZE))
                        notify(utp, offset);
        }