Fix an issue with requesting a T38 reinvite before the call is answered.

The code responsible for sending the T38 reinvite did not check if an INVITE was
already being handled. This caused things to get confused and the call to fail.
The code now defers sending the T38 reinvite until the current INVITE is done being
handled.

(issue AST-191)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@182022 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -6081,7 +6081,11 @@ static int sip_indicate(struct ast_channel *ast, int condition, const void *data
 			case AST_T38_REQUEST_NEGOTIATE:		/* Request T38 */
 				if (p->t38.state != T38_ENABLED) {
 					change_t38_state(p, T38_LOCAL_REINVITE);
-					transmit_reinvite_with_sdp(p, TRUE, FALSE);
+					if (!p->pendinginvite) {
+						transmit_reinvite_with_sdp(p, TRUE, FALSE);
+					} else if (!ast_test_flag(&p->flags[0], SIP_PENDINGBYE)) {
+						ast_set_flag(&p->flags[0], SIP_NEEDREINVITE);
+					}
 				}
 				break;
 			case AST_T38_TERMINATED:
@@ -16491,7 +16495,7 @@ static void check_pendings(struct sip_pvt *p)
 		} else {
 			ast_debug(2, "Sending pending reinvite on '%s'\n", p->callid);
 			/* Didn't get to reinvite yet, so do it now */
-			transmit_reinvite_with_sdp(p, FALSE, FALSE);
+			transmit_reinvite_with_sdp(p, (p->t38.state == T38_LOCAL_REINVITE ? TRUE : FALSE), FALSE);
 			ast_clear_flag(&p->flags[0], SIP_NEEDREINVITE);	
 		}
 	}