manager: Clarify eventfilter documentation. Textual changes only.

Review: https://reviewboard.asterisk.org/r/3133/
........

Merged revisions 406079 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@406080 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configs/manager.conf.sample

@@ -94,12 +94,13 @@ bindaddr = 0.0.0.0
 ; user.
 ;
 ;eventfilter=Event: Newchannel
-;eventfilter=!Channel: DAHDI*
-; The eventfilter option is used to whitelist or blacklist events per user to be
-; reported with regular expressions and are allowed if both the regex matches
-; and the user has read access set below. Filters are assumed to be for whitelisting
-; unless preceeded by an exclamation point, which marks it as being black.
-; Evaluation of the filters is as follows:
+;eventfilter=!Channel: DAHDI.*
+; The eventfilter option is used to whitelist or blacklist events per user.
+; A filter consists of a (basic/old-style and unanchored) regular expression
+; that is run on the entire event data. If the first character of the filter
+; is an exclamation mark (!), the filter is appended to the blacklist instead
+; of the whitelist. After first checking the read access below, the regular
+; expression filters are processed as follows:
 ; - If no filters are configured all events are reported as normal.
 ; - If there are white filters only: implied black all filter processed first,
 ; then white filters.

main/manager.c

@@ -4772,8 +4772,8 @@ static enum add_filter_result manager_add_filter(const char *filter_pattern, str
 		is_blackfilter = 0;
 	}
 
-	if (regcomp(new_filter, filter_pattern, 0)) {
-		ao2_t_ref(new_filter, -1, "failed to make regx");
+	if (regcomp(new_filter, filter_pattern, 0)) { /* XXX: the only place we use non-REG_EXTENDED */
+		ao2_t_ref(new_filter, -1, "failed to make regex");
 		return FILTER_COMPILE_FAIL;
 	}