Making some changes designed to not allow for a corrupted mailstream for a vm_state.

1. Add locking to the vm_state retrieval functions so that no linked list corruption occurs.
2. Make sure to always grab the persistent vm_state when mailstream access is necessary.
3. Correct an incorrect return value in the init_mailstream function.

(closes issue #11304, reported by dwhite)



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@97192 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_voicemail.c

@@ -2569,11 +2569,11 @@ static int copy_message(struct ast_channel *chan, struct ast_vm_user *vmu, int i
 		ast_log(LOG_WARNING, "Unable to copy mail, mailbox %s is full\n", recip->mailbox);
 		return -1;
 	}
-	if (!(sendvms = get_vm_state_by_imapuser(vmu->imapuser, 2))) {
+	if (!(sendvms = get_vm_state_by_imapuser(vmu->imapuser, 0))) {
 		ast_log(LOG_ERROR, "Couldn't get vm_state for originator's mailbox!!\n");
 		return -1;
 	}
-	if (!(destvms = get_vm_state_by_imapuser(recip->imapuser, 2))) {
+	if (!(destvms = get_vm_state_by_imapuser(recip->imapuser, 0))) {
 		ast_log(LOG_ERROR, "Couldn't get vm_state for destination mailbox!\n");
 		return -1;
 	}
@@ -4721,7 +4721,7 @@ static int init_mailstream(struct vm_state *vms, int box)
 		stream = mail_open (stream, tmp, debug ? OP_DEBUG : NIL);
 		if (stream == NIL) {
 			ast_log (LOG_ERROR, "Can't connect to imap server %s\n", tmp);
-			return NIL;
+			return -1;
 		}
 		get_mailbox_delimiter(stream);
 		/* update delimiter in imapfolder */
@@ -8805,6 +8805,7 @@ static struct vm_state *get_vm_state_by_imapuser(char *user, int interactive)
 {
 	struct vmstate *vlist = NULL;
 
+	ast_mutex_lock(&vmstate_lock);
 	vlist = vmstates;
 	while (vlist) {
 		if (vlist->vms) {
@@ -8826,6 +8827,7 @@ static struct vm_state *get_vm_state_by_imapuser(char *user, int interactive)
 		}
 		vlist = vlist->next;
 	}
+	ast_mutex_unlock(&vmstate_lock);
 	if (option_debug > 2)
 		ast_log(LOG_DEBUG, "%s not found in vmstates\n",user);
 	return NULL;
@@ -8834,7 +8836,8 @@ static struct vm_state *get_vm_state_by_imapuser(char *user, int interactive)
 static struct vm_state *get_vm_state_by_mailbox(const char *mailbox, int interactive)
 { 
 	struct vmstate *vlist = NULL;
-	
+
+	ast_mutex_lock(&vmstate_lock);
 	vlist = vmstates;
 	if (option_debug > 2) 
 		ast_log(LOG_DEBUG, "Mailbox set to %s\n",mailbox);
@@ -8858,6 +8861,7 @@ static struct vm_state *get_vm_state_by_mailbox(const char *mailbox, int interac
 		}
 		vlist = vlist->next;
 	}
+	ast_mutex_unlock(&vmstate_lock);
 	if (option_debug > 2)
 		ast_log(LOG_DEBUG, "%s not found in vmstates\n",mailbox);
 	return NULL;