Issue 9527 - upon entering a folder, no message is selected (curmsg == -1), so deleting causes memory corruption (beyond bounds)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.2@63359 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_voicemail.c

@@ -5443,6 +5443,7 @@ static int vm_execmain(struct ast_channel *chan, void *data)
 			}
 			break;
 		case '7':
+			if (vms.curmsg >= 0 && vms.curmsg <= vms.lastmsg) {
 				vms.deleted[vms.curmsg] = !vms.deleted[vms.curmsg];
 				if (useadsi)
 					adsi_delete(chan, &vms);
@@ -5458,6 +5459,8 @@ static int vm_execmain(struct ast_channel *chan, void *data)
 						cmd = ast_play_and_wait(chan, "vm-nomore");
 					}
 				}
+			} else /* Delete not valid if we haven't selected a message */
+				cmd = 0;
 			break;
 	
 		case '8':