Index: chan_zap.c
===================================================================
RCS file: /usr/cvsroot/asterisk/channels/chan_zap.c,v
retrieving revision 1.344.2.15
diff -u -r1.344.2.15 chan_zap.c
--- chan_zap.c	15 Apr 2005 07:15:39 -0000	1.344.2.15
+++ chan_zap.c	17 May 2005 17:51:43 -0000
@@ -215,6 +215,10 @@
 
 static int busycount = 3;
 
+static int answeronpolarityswitch = 0;
+
+static int hanguponpolarityswitch = 0;
+
 static int callprogress = 0;
 
 static char accountcode[20] = "";
@@ -389,6 +393,9 @@
 #define SUB_CALLWAIT	1			/* Call-Waiting call on hold */
 #define SUB_THREEWAY	2			/* Three-way call */
 
+#define POLARITY_IDLE   0
+#define POLARITY_REV    1
+
 
 static struct zt_distRings drings;
 
@@ -483,6 +490,7 @@
 	int cid_signalling;			/* CID signalling type bell202 or v23 */
 	int cid_start;				/* CID start indicator, polarity or ring */
 	int hidecallerid;
+	int polarity;
 	int callreturn;
 	int permhidecallerid;		/* Whether to hide our outgoing caller ID or not */
 	int restrictcid;		/* Whether restrict the callerid -> only send ANI */
@@ -514,6 +522,8 @@
 	int dnd;
 	int busydetect;
 	int busycount;
+	int answeronpolarityswitch;
+	int hanguponpolarityswitch;
 	int callprogress;
 	int priindication_oob;
 	struct timeval flashtime;	/* Last flash-hook time */
@@ -846,6 +856,7 @@
 	p->subs[x].chan = 0;
 	p->subs[x].owner = NULL;
 	p->subs[x].inthreeway = 0;
+	p->polarity = POLARITY_IDLE;
 	memset(&p->subs[x].curconf, 0, sizeof(p->subs[x].curconf));
 	return 0;
 }
@@ -1991,6 +2002,7 @@
 		p->subs[index].linear = 0;
 		p->subs[index].needcallerid = 0;
 		zt_setlinear(p->subs[index].zfd, 0);
+		p->polarity = POLARITY_IDLE;
 		if (index == SUB_REAL) {
 			if ((p->subs[SUB_CALLWAIT].zfd > -1) && (p->subs[SUB_THREEWAY].zfd > -1)) {
 				ast_log(LOG_DEBUG, "Normal call hung up with both three way call and a call waiting call in place?\n");
@@ -3145,10 +3157,13 @@
 							ast_log(LOG_DEBUG, "Done dialing, but waiting for progress detection before doing more...\n");
 						} else if (p->confirmanswer || (!p->dialednone && ((p->sig == SIG_EM) || (p->sig == SIG_EM_E1) ||  (p->sig == SIG_EMWINK) || (p->sig == SIG_FEATD) || (p->sig == SIG_FEATDMF) || (p->sig == SIG_E911) || (p->sig == SIG_FEATB) || (p->sig == SIG_SF) || (p->sig == SIG_SFWINK) || (p->sig == SIG_SF_FEATD) || (p->sig == SIG_SF_FEATDMF) || (p->sig == SIG_SF_FEATB)))) {
 							ast_setstate(ast, AST_STATE_RINGING);
-						} else {
+						} else if (!p->answeronpolarityswitch) {
 							ast_setstate(ast, AST_STATE_UP);
 							p->subs[index].f.frametype = AST_FRAME_CONTROL;
 							p->subs[index].f.subclass = AST_CONTROL_ANSWER;
+							p->polarity=POLARITY_IDLE;
+						} else {
+							p->polarity=POLARITY_IDLE;
 						}
 					}
 				}
@@ -3665,6 +3680,28 @@
 				break;
 			}
 			break;
+		case ZT_EVENT_POLARITY:
+			if (	p->hanguponpolarityswitch &&
+				p->polarity == POLARITY_REV &&
+				( ast->_state == AST_STATE_UP ||
+				  ast->_state == AST_STATE_RING )) {
+				//hangup
+				ast_log(LOG_VERBOSE, "Hangup due to Reverse Polarity on channel %d\n", p->channel);
+				ast_softhangup(p->owner, AST_SOFTHANGUP_EXPLICIT);
+			} else if (p->answeronpolarityswitch && 
+					p->polarity==POLARITY_IDLE &&
+					(ast->_state == AST_STATE_DIALING ||
+					 ast->_state == AST_STATE_RINGING)) {
+				//answer
+				ast_log(LOG_VERBOSE, "Answering on polarity switch on channel %d\n", p->channel);
+	                        p->subs[index].f.frametype = AST_FRAME_CONTROL;
+	                        p->subs[index].f.subclass = AST_CONTROL_ANSWER;
+				ast_setstate(p->owner, AST_STATE_UP);
+				p->polarity=POLARITY_REV;
+			} else {
+				ast_log(LOG_VERBOSE, "Ignoring polarity switch on channel %d. Polarity is unchanged (%s)\n",p->channel,p->polarity==POLARITY_IDLE?"POLARITY_IDLE":"POLARITY_REV");
+			}
+			break;
 		default:
 			ast_log(LOG_DEBUG, "Dunno what to do with event %d on channel %d\n", res, p->channel);
 	}
@@ -5704,6 +5741,7 @@
 		case SIG_FXSLS:
 		case SIG_FXSKS:
 		case SIG_FXSGS:
+			i->polarity=POLARITY_REV;
 			if (i->cid_start == CID_START_POLARITY) {
 				ast_verbose(VERBOSE_PREFIX_2 "Starting post polarity "
 					    "CID detection on channel %d\n",
@@ -6460,6 +6498,8 @@
 		tmp->echocanbridged = echocanbridged;
 		tmp->busydetect = busydetect;
 		tmp->busycount = busycount;
+		tmp->answeronpolarityswitch = answeronpolarityswitch;
+		tmp->hanguponpolarityswitch = hanguponpolarityswitch;
 		tmp->callprogress = callprogress;
 		tmp->cancallforward = cancallforward;
 		tmp->dtmfrelax = relaxdtmf;
@@ -6470,6 +6510,7 @@
 		tmp->use_callerid = use_callerid;
 		tmp->cid_signalling = cid_signalling;
 		tmp->cid_start = cid_start;
+		tmp->polarity = POLARITY_IDLE;
 		tmp->zaptrcallerid = zaptrcallerid;
 		tmp->restrictcid = restrictcid;
 		tmp->use_callingpres = use_callingpres;
@@ -9222,6 +9263,10 @@
 				callprogress |= 1;
 			else
 				callprogress &= ~1;
+		} else if (!strcasecmp(v->name, "answeronpolarityswitch")) {
+			answeronpolarityswitch = ast_true(v->value);
+		} else if (!strcasecmp(v->name, "hanguponpolarityswitch")) {
+			hanguponpolarityswitch = ast_true(v->value);
 		} else if (!strcasecmp(v->name, "faxdetect")) {
 			if (!strcasecmp(v->value, "incoming")) {
 				callprogress |= 4;