Fix #102: allow '.' in tag names, regression in v2.7.1

RFC3164 specifies; "The TAG is a string of ABNF alphanumeric characters
  that MUST NOT exceed 32 characters.  Any non-alphanumeric character
  will terminate the TAG field and will be assumed to be the starting
  character of the CONTENT field."

Strictly speaking, ABNF (Augmented Backus-Naur Form) only includes the
alphanumeric characters, meaning just be letters and digits.

However, in real-life scenarios, and per previous behavior, we should
definitely allow '.' as well.  The existing argument to `strspn()` is
from FreeBSD, which for some reason do *not* allow '.', but they do
also allow '_-/' ... '/' seems like the real outlier here.

Signed-off-by: Joachim Wiberg <[email protected]>

Author: troglobit

src/syslogd.c

@@ -1223,7 +1223,7 @@ parsemsg_rfc3164_app_name_procid(char **msg, char **app_name, char **procid)
 	    "abcdefghijklmnopqrstuvwxyz"
 	    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 	    "0123456789"
-	    "_-/");
+	    "._-/");
 	if (app_name_length == 0)
 		goto bad;
 	m += app_name_length;