Fix a variety of memory leaks

This patch addresses a number of memory leaks in a variety of modules that were
found by a static analysis tool.  A brief summary of the changes:

* app_minivm:       free ast_str objects on off nominal paths
* app_page:         free the ast_dial object if the requested channel technology
                    cannot be appended to the dialing structure
* app_queue:        if a penalty rule failed to match any existing rule list
                    names, the created rule would not be inserted and its memory
                    would be leaked
* app_read:         dispose of the created silence detector in the presence of
                    off nominal circumstances
* app_voicemail:    dispose of an allocated unique ID field for MWI event
                    un-subscribe requests in off nominal paths; dispose of
                    configuration objects when using the secret.conf option
* chan_dahdi:       dispose of the allocated frame produced by ast_dsp_process
* chan_iax2:        properly unref peer in CLI command "iax2 unregister"
* chan_sip:         dispose of the allocated frame produced by sip_rtp_read's
                    call of ast_dsp_process; free memory in parse unit tests
* func_dialgroup:   properly deref ao2 object grhead in nominal path of
                    dialgroup_read
* func_odbc:        free resultset in off nominal paths of odbc_read
* cli:              free match_list in off nominal paths of CLI match completion
* config:           free comment_buffer/list_buffer when configuration file load
                    is unchanged; free the same buffers any time they were
                    created and config files were processed
* data:             free XML nodes in various places
* enum:             free context buffer in off nominal paths
* features:         free ast_call_feature in off nominal paths of applicationmap
                    config processing
* netsock2:         users of ast_sockaddr_resolve pass in an ast_sockaddr struct
                    that is allocated by the method.  Failures in
                    ast_sockaddr_resolve could result in the users of the method
                    not knowing whether or not the buffer was allocated.  The
                    method will now not allocate the ast_sockaddr struct if it
                    will return failure.
* pbx:              cleanup hash table traversals in off nominal paths; free
                    ignore pattern buffer if it already exists for the specified
                    context
* xmldoc:           cleanup various nodes when we no longer need them
* main/editline:    various cleanup of pointers not being freed before being
                    assigned to other memory, cleanup along off nominal paths
* menuselect/mxml:  cleanup of value buffer for an attribute when that attribute
                    did not specify a value
* res_calendar*:    responses are allocated via the various *_request method
                    returns and should not be allocated in the various
                    write_event methods; ensure attendee buffer is freed if no
                    data exists in the parsed node; ensure that calendar objects
                    are de-ref'd appropriately
* res_jabber:       free buffer in off nominal path
* res_musiconhold:  close the DIR* object in off nominal paths
* res_rtp_asterisk: if we run out of ports, close the rtp socket object and free
                    the rtp object
* res_srtp:         if we fail to create the session in libsrtp, destroy the
                    temporary ast_srtp object

(issue ASTERISK-19665)
Reported by: Matt Jordan

Review: https://reviewboard.asterisk.org/r/1922
........

Merged revisions 366880 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 366881 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@366917 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_calendar.c

@@ -374,6 +374,7 @@ static int calendar_is_busy(struct ast_calendar *cal)
 
 static enum ast_device_state calendarstate(const char *data)
 {
+	enum ast_device_state state;
 	struct ast_calendar *cal;
 
 	if (ast_strlen_zero(data) || (!(cal = find_calendar(data)))) {
@@ -381,10 +382,13 @@ static enum ast_device_state calendarstate(const char *data)
 	}
 
 	if (cal->tech->is_busy) {
-		return cal->tech->is_busy(cal) ? AST_DEVICE_INUSE : AST_DEVICE_NOT_INUSE;
+		state = cal->tech->is_busy(cal) ? AST_DEVICE_INUSE : AST_DEVICE_NOT_INUSE;
+	} else {
+		state = calendar_is_busy(cal) ? AST_DEVICE_INUSE : AST_DEVICE_NOT_INUSE;
 	}
 
-	return calendar_is_busy(cal) ? AST_DEVICE_INUSE : AST_DEVICE_NOT_INUSE;
+	cal = unref_calendar(cal);
+	return state;
 }
 
 static struct ast_calendar *build_calendar(struct ast_config *cfg, const char *cat, const struct ast_calendar_tech *tech)
@@ -1060,6 +1064,7 @@ static int calendar_busy_exec(struct ast_channel *chan, const char *cmd, char *d
 	}
 
 	strcpy(buf, calendar_is_busy(cal) ? "1" : "0");
+	cal = unref_calendar(cal);
 
 	return 0;
 }
@@ -1214,6 +1219,8 @@ static int calendar_query_exec(struct ast_channel *chan, const char *cmd, char *
 			ast_debug(10, "%s (%ld - %ld) overlapped with (%ld - %ld)\n", event->summary, (long) event->start, (long) event->end, (long) start, (long) end);
 			if (add_event_to_list(events, event, start, end) < 0) {
 				event = ast_calendar_unref_event(event);
+				cal = unref_calendar(cal);
+				ao2_ref(events, -1);
 				ao2_iterator_destroy(&i);
 				return -1;
 			}
@@ -1231,6 +1238,8 @@ static int calendar_query_exec(struct ast_channel *chan, const char *cmd, char *
 
 	if (!(eventlist_datastore = ast_datastore_alloc(&eventlist_datastore_info, buf))) {
 		ast_log(LOG_ERROR, "Could not allocate datastore!\n");
+		cal = unref_calendar(cal);
+		ao2_ref(events, -1);
 		return -1;
 	}
 
@@ -1241,6 +1250,7 @@ static int calendar_query_exec(struct ast_channel *chan, const char *cmd, char *
 	ast_channel_datastore_add(chan, eventlist_datastore);
 	ast_channel_unlock(chan);
 
+	cal = unref_calendar(cal);
 	return 0;
 }