More re #1481: Destroying the regc may lead to dangling binding in the register, so instead of destroying the regc, instruct it to release the transport instead

git-svn-id: http://svn.pjsip.org/repos/pjproject/branches/1.x@4037 74dad513-b988-da41-8d7b-12977e46ad98

3 files changed, 31 insertions, 4 deletions

diff --git a/pjsip/include/pjsip-ua/sip_regc.h b/pjsip/include/pjsip-ua/sip_regc.h
index 4ef4bbaa..c2aec0c8 100644
--- a/pjsip/include/pjsip-ua/sip_regc.h
+++ b/pjsip/include/pjsip-ua/sip_regc.h
@@ -265,6 +265,19 @@ PJ_DECL(pj_status_t) pjsip_regc_set_route_set(pjsip_regc *regc,
 PJ_DECL(pj_status_t) pjsip_regc_set_transport(pjsip_regc *regc,
 					      const pjsip_tpselector *sel);
 
+/**
+ * Release the reference to current transport being used by the regc, if any.
+ * The regc keeps the reference to the last transport being used in order
+ * to prevent it from being destroyed. In some situation however, such as
+ * when the transport is disconnected, it is necessary to instruct the
+ * regc to release this reference so that the transport can be destroyed.
+ * See https://trac.pjsip.org/repos/ticket/1481 for background info.
+ *
+ * @param regc	    The client registration instance.
+ *
+ * @return	    PJ_SUCCESS on success, or the appropriate error code.
+ */
+PJ_DECL(pj_status_t) pjsip_regc_release_transport(pjsip_regc *regc);
 
 /**
  * Add headers to be added to outgoing REGISTER requests.
diff --git a/pjsip/src/pjsip-ua/sip_reg.c b/pjsip/src/pjsip-ua/sip_reg.c
index 750e22f7..c02c17bb 100644
--- a/pjsip/src/pjsip-ua/sip_reg.c
+++ b/pjsip/src/pjsip-ua/sip_reg.c
@@ -440,6 +440,17 @@ PJ_DEF(pj_status_t) pjsip_regc_set_transport( pjsip_regc *regc,
     return PJ_SUCCESS;
 }
 
+/* Release transport */
+PJ_DEF(pj_status_t) pjsip_regc_release_transport(pjsip_regc *regc)
+{
+    PJ_ASSERT_RETURN(regc, PJ_EINVAL);
+    if (regc->last_transport) {
+	pjsip_transport_dec_ref(regc->last_transport);
+	regc->last_transport = NULL;
+    }
+    return PJ_SUCCESS;
+}
+
 
 PJ_DEF(pj_status_t) pjsip_regc_add_headers( pjsip_regc *regc,
 					    const pjsip_hdr *hdr_list)
@@ -1269,7 +1280,9 @@ PJ_DEF(pj_status_t) pjsip_regc_send(pjsip_regc *regc, pjsip_tx_data *tdata)
     pj_lock_acquire(regc->lock);
 
     /* Get last transport used and add reference to it */
-    if (tdata->tp_info.transport != regc->last_transport) {
+    if (tdata->tp_info.transport != regc->last_transport &&
+	status==PJ_SUCCESS)
+    {
 	if (regc->last_transport) {
 	    pjsip_transport_dec_ref(regc->last_transport);
 	    regc->last_transport = NULL;
diff --git a/pjsip/src/pjsua-lib/pjsua_acc.c b/pjsip/src/pjsua-lib/pjsua_acc.c
index a0a5d81d..4758f391 100644
--- a/pjsip/src/pjsua-lib/pjsua_acc.c
+++ b/pjsip/src/pjsua-lib/pjsua_acc.c
@@ -2821,11 +2821,12 @@ void pjsua_acc_on_tp_state_changed(pjsip_transport *tp,
 	    continue;
 	}
 
-	/* Destroy regc to release transport immediately */
+	/* Release regc transport immediately
+	 * See https://trac.pjsip.org/repos/ticket/1481
+	 */
 	if (pjsua_var.acc[i].regc) {
-	    pjsip_regc_destroy(pjsua_var.acc[i].regc);
+	    pjsip_regc_release_transport(pjsua_var.acc[i].regc);
 	}
-	pjsua_var.acc[i].regc = NULL;
 
 	/* Schedule reregistration for this account */
 	schedule_reregistration(acc);