Fix improper usage of scheduler exposed by 5c713fdf18f

When 5c713fdf18f was merged, it allowed for scheduled items to have an ID of
'0' returned. While this was valid per the documentation for the API, it was
apparently never returned previously. As a result, several users of the
scheduler API viewed the result as being invalid, causing them to reschedule
already scheduled items or otherwise fail in interesting ways.

This patch corrects the users such that they view '0' as valid, and a returned
ID of -1 as being invalid.

Note that the failing HEP RTCP tests now pass with this patch. These tests
failed due to a duplicate scheduling of the RTCP transmissions.

ASTERISK-25449 #close

Change-Id: I019a9aa8b6997584f66876331675981ac9e07e39

3 files changed, 17 insertions, 17 deletions

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 8d5af2f09..349042c9d 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -4322,7 +4322,7 @@ void sip_scheddestroy(struct sip_pvt *p, int ms)
 	}
 	p->autokillid = ast_sched_add(sched, ms, __sip_autodestruct, dialog_ref(p, "setting ref as passing into ast_sched_add for __sip_autodestruct"));
 
-	if (p->stimer && p->stimer->st_active == TRUE && p->stimer->st_schedid > 0) {
+	if (p->stimer && p->stimer->st_active == TRUE && p->stimer->st_schedid > -1) {
 		stop_session_timer(p);
 	}
 }
@@ -22743,7 +22743,7 @@ static void check_pendings(struct sip_pvt *p)
 		sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
 	} else if (ast_test_flag(&p->flags[0], SIP_NEEDREINVITE)) {
 		/* if we can't REINVITE, hold it for later */
-		if (p->pendinginvite || p->invitestate == INV_CALLING || p->invitestate == INV_PROCEEDING || p->invitestate == INV_EARLY_MEDIA || p->waitid > 0) {
+		if (p->pendinginvite || p->invitestate == INV_CALLING || p->invitestate == INV_PROCEEDING || p->invitestate == INV_EARLY_MEDIA || p->waitid > -1) {
 			ast_debug(2, "NOT Sending pending reinvite (yet) on '%s'\n", p->callid);
 		} else {
 			ast_debug(2, "Sending pending reinvite on '%s'\n", p->callid);
diff --git a/channels/chan_skinny.c b/channels/chan_skinny.c
index 08629fd78..6e59e0162 100644
--- a/channels/chan_skinny.c
+++ b/channels/chan_skinny.c
@@ -4863,7 +4863,7 @@ static int skinny_dialer_cb(const void *data)
 {
 	struct skinny_subchannel *sub = (struct skinny_subchannel *)data;
 	SKINNY_DEBUG(DEBUG_SUB, 3, "Sub %u - Dialer called from SCHED %d\n", sub->callid, sub->dialer_sched);
-	sub->dialer_sched = 0;
+	sub->dialer_sched = -1;
 	skinny_dialer(sub, 1);
 	return 0;
 }
@@ -4872,7 +4872,7 @@ static int skinny_autoanswer_cb(const void *data)
 {
 	struct skinny_subchannel *sub = (struct skinny_subchannel *)data;
 	skinny_locksub(sub);
-	sub->aa_sched = 0;
+	sub->aa_sched = -1;
 	setsubstate(sub, SKINNY_CONNECTED);
 	skinny_unlocksub(sub);
 	return 0;
@@ -4882,7 +4882,7 @@ static int skinny_cfwd_cb(const void *data)
 {
 	struct skinny_subchannel *sub = (struct skinny_subchannel *)data;
 	struct skinny_line *l = sub->line;
-	sub->cfwd_sched = 0;
+	sub->cfwd_sched = -1;
 	SKINNY_DEBUG(DEBUG_SUB, 3, "Sub %u - CFWDNOANS to %s.\n", sub->callid, l->call_forward_noanswer);
 	ast_channel_call_forward_set(sub->owner, l->call_forward_noanswer);
 	ast_queue_control(sub->owner, AST_CONTROL_REDIRECTING);
@@ -4924,7 +4924,7 @@ static int skinny_call(struct ast_channel *ast, const char *dest, int timeout)
 	skinny_locksub(sub);
 	AST_LIST_TRAVERSE(ast_channel_varshead(ast), current, entries) {
 		if (!(strcmp(ast_var_name(current), "SKINNY_AUTOANSWER"))) {
-			if (d->hookstate == SKINNY_ONHOOK && !sub->aa_sched) {
+			if (d->hookstate == SKINNY_ONHOOK && sub->aa_sched < 0) {
 				char buf[24];
 				int aatime;
 				char *stringp = buf, *curstr;
@@ -5389,9 +5389,9 @@ static struct ast_channel *skinny_new(struct skinny_line *l, struct skinny_subli
 			sub->xferor = 0;
 			sub->related = NULL;
 			sub->calldirection = direction;
-			sub->aa_sched = 0;
-			sub->dialer_sched = 0;
-			sub->cfwd_sched = 0;
+			sub->aa_sched = -1;
+			sub->dialer_sched = -1;
+			sub->cfwd_sched = -1;
 			sub->dialType = DIALTYPE_NORMAL;
 			sub->getforward = 0;
 
@@ -5550,17 +5550,17 @@ static void setsubstate(struct skinny_subchannel *sub, int state)
 
 	if (sub->dialer_sched) {
 		skinny_sched_del(sub->dialer_sched, sub);
-		sub->dialer_sched = 0;
+		sub->dialer_sched = -1;
 	}
 
 	if (state != SUBSTATE_RINGIN && sub->aa_sched) {
 		skinny_sched_del(sub->aa_sched, sub);
-		sub->aa_sched = 0;
+		sub->aa_sched = -1;
 		sub->aa_beep = 0;
 		sub->aa_mute = 0;
 	}
 
-	if (sub->cfwd_sched) {
+	if (sub->cfwd_sched > -1) {
 		if (state == SUBSTATE_CONNECTED) {
 			if (skinny_sched_del(sub->cfwd_sched, sub)) {
 				SKINNY_DEBUG(DEBUG_SUB, 3, "Sub %u - trying to change state from %s to %s, but already forwarded because no answer.\n",
@@ -5568,7 +5568,7 @@ static void setsubstate(struct skinny_subchannel *sub, int state)
 				skinny_unlocksub(sub);
 				return;
 			}
-			sub->cfwd_sched = 0;
+			sub->cfwd_sched = -1;
 		} else if (state == SUBSTATE_ONHOOK) {
 			skinny_sched_del(sub->cfwd_sched, sub);
 		}
@@ -6240,7 +6240,7 @@ static int handle_keypad_button_message(struct skinny_req *req, struct skinnyses
 	if ((sub->owner && ast_channel_state(sub->owner) <  AST_STATE_UP)) {
 		if (sub->dialer_sched && !skinny_sched_del(sub->dialer_sched, sub)) {
 			SKINNY_DEBUG(DEBUG_SUB, 3, "Sub %u - Got a digit and not timed out, so try dialing\n", sub->callid);
-			sub->dialer_sched = 0;
+			sub->dialer_sched = -1;
 			len = strlen(sub->exten);
 			if (len == 0) {
 				transmit_stop_tone(d, l->instance, sub->callid);
@@ -7077,7 +7077,7 @@ static int handle_soft_key_event_message(struct skinny_req *req, struct skinnyse
 			d->name, instance, callreference);
 		if (sub->dialer_sched && !skinny_sched_del(sub->dialer_sched, sub)) {
 			size_t len;
-			sub->dialer_sched = 0;
+			sub->dialer_sched = -1;
 			len = strlen(sub->exten);
 			if (len > 0) {
 				sub->exten[len-1] = '\0';
diff --git a/res/res_rtp_asterisk.c b/res/res_rtp_asterisk.c
index 870c4f1b7..2e285ebef 100644
--- a/res/res_rtp_asterisk.c
+++ b/res/res_rtp_asterisk.c
@@ -3311,7 +3311,7 @@ static int ast_rtp_raw_write(struct ast_rtp_instance *instance, struct ast_frame
 			rtp->txcount++;
 			rtp->txoctetcount += (res - hdrlen);
 
-			if (rtp->rtcp && rtp->rtcp->schedid < 1) {
+			if (rtp->rtcp && rtp->rtcp->schedid < 0) {
 				ast_debug(1, "Starting RTCP transmission on RTP instance '%p'\n", instance);
 				ao2_ref(instance, +1);
 				rtp->rtcp->schedid = ast_sched_add(rtp->sched, ast_rtcp_calc_interval(rtp), ast_rtcp_write, instance);
@@ -4521,7 +4521,7 @@ static struct ast_frame *ast_rtp_read(struct ast_rtp_instance *instance, int rtc
 	}
 
 	/* Do not schedule RR if RTCP isn't run */
-	if (rtp->rtcp && !ast_sockaddr_isnull(&rtp->rtcp->them) && rtp->rtcp->schedid < 1) {
+	if (rtp->rtcp && !ast_sockaddr_isnull(&rtp->rtcp->them) && rtp->rtcp->schedid < 0) {
 		/* Schedule transmission of Receiver Report */
 		ao2_ref(instance, +1);
 		rtp->rtcp->schedid = ast_sched_add(rtp->sched, ast_rtcp_calc_interval(rtp), ast_rtcp_write, instance);