Index: apps/app_dial.c
===================================================================
--- apps/app_dial.c	(revision 123644)
+++ apps/app_dial.c	(working copy)
@@ -485,8 +485,11 @@
 		*stuff++ = '\0';
 		tech = tmpchan;
 	} else {
-		const char *forward_context = pbx_builtin_getvar_helper(c, "FORWARD_CONTEXT");
+		const char *forward_context;
+		ast_channel_lock(c);
+		forward_context = pbx_builtin_getvar_helper(c, "FORWARD_CONTEXT"); 
 		snprintf(tmpchan, sizeof(tmpchan), "%s@%s", c->call_forward, forward_context ? forward_context : c->context);
+		ast_channel_unlock(c);
 		stuff = tmpchan;
 		tech = "Local";
 	}
@@ -800,7 +803,9 @@
 			/* now f is guaranteed non-NULL */
 			if (f->frametype == AST_FRAME_DTMF) {
 				if (ast_test_flag64(peerflags, OPT_DTMF_EXIT)) {
-					const char *context = pbx_builtin_getvar_helper(in, "EXITCONTEXT");
+					const char *context;
+					ast_channel_lock(in);
+					context = pbx_builtin_getvar_helper(in, "EXITCONTEXT");
 					if (onedigit_goto(in, context, (char) f->subclass, 1)) {
 						ast_verb(3, "User hit %c to disconnect call.\n", f->subclass);
 						*to = 0;
@@ -808,8 +813,10 @@
 						*result = f->subclass;
 						strcpy(pa->status, "CANCEL");
 						ast_frfree(f);
+						ast_channel_unlock(in);
 						return NULL;
 					}
+					ast_channel_unlock(in);
 				}
 
 				if (ast_test_flag64(peerflags, OPT_CALLER_HANGUP) &&
@@ -924,17 +931,26 @@
 				config->play_warning = config->warning_freq = 0;
 		}
 	}
+	
+	ast_channel_lock(chan);
 
-	var = pbx_builtin_getvar_helper(chan, "LIMIT_PLAYAUDIO_CALLER");
+	var = pbx_builtin_getvar_helper(chan, "LIMIT_PLAYAUDIO_CALLER"); 
+
 	play_to_caller = var ? ast_true(var) : 1;
-
+	
 	var = pbx_builtin_getvar_helper(chan, "LIMIT_PLAYAUDIO_CALLEE");
 	play_to_callee = var ? ast_true(var) : 0;
 
 	if (!play_to_caller && !play_to_callee)
 		play_to_caller = 1;
 
-	var = pbx_builtin_getvar_helper(chan, "LIMIT_WARNING_FILE");
+	
+	if ((var = pbx_builtin_getvar_helper(chan, "LIMIT_WARNING_FILE"))) {
+		var = ast_strdupa(var);
+	}
+
+	
+
 	config->warning_sound = S_OR(var, "timeleft");
 
 	/* The code looking at config wants a NULL, not just "", to decide
@@ -942,9 +958,18 @@
 	 * Note, pbx_builtin_getvar_helper _can_ return NULL if the variable is
 	 * not found.
 	 */
-	var = pbx_builtin_getvar_helper(chan, "LIMIT_TIMEOUT_FILE");
+
+	if ((var = pbx_builtin_getvar_helper(chan, "LIMIT_TIMEOUT_FILE"))) {
+		var = ast_strdupa(var);
+	}
+	
 	config->end_sound = S_OR(var, NULL);
-	var = pbx_builtin_getvar_helper(chan, "LIMIT_CONNECT_FILE");
+	
+	if ((var = pbx_builtin_getvar_helper(chan, "LIMIT_CONNECT_FILE"))) {
+		var = ast_strdupa(var);
+	}
+	ast_channel_unlock(chan);
+
 	config->start_sound = S_OR(var, NULL);
 
 	/* undo effect of S(x) in case they are both used */
@@ -1326,13 +1351,15 @@
 		*continue_exec = 0;
 
 	/* If a channel group has been specified, get it for use when we create peer channels */
+
+	ast_channel_lock(chan);
 	if ((outbound_group = pbx_builtin_getvar_helper(chan, "OUTBOUND_GROUP_ONCE"))) {
+		outbound_group = ast_strdupa(outbound_group);	
+		pbx_builtin_setvar_helper(chan, "OUTBOUND_GROUP_ONCE", NULL);
+	} else if ((outbound_group = pbx_builtin_getvar_helper(chan, "OUTBOUND_GROUP"))) {
 		outbound_group = ast_strdupa(outbound_group);
-		pbx_builtin_setvar_helper(chan, "OUTBOUND_GROUP_ONCE", NULL);
-	} else {
-		outbound_group = pbx_builtin_getvar_helper(chan, "OUTBOUND_GROUP");
 	}
-
+	ast_channel_unlock(chan);	
 	ast_copy_flags64(peerflags, &opts, OPT_DTMF_EXIT | OPT_GO_ON | OPT_ORIGINAL_CLID | OPT_CALLER_HANGUP | OPT_IGNORE_FORWARDING);
 
 	/* Create datastore for channel dial features for caller */
@@ -1644,11 +1671,14 @@
 			ast_cdr_setdestchan(chan->cdr, peer->name);
 		if (peer->name)
 			pbx_builtin_setvar_helper(chan, "DIALEDPEERNAME", peer->name);
-
-		number = pbx_builtin_getvar_helper(peer, "DIALEDPEERNUMBER");
+		
+		ast_channel_lock(peer);
+		number = pbx_builtin_getvar_helper(peer, "DIALEDPEERNUMBER"); 
 		if (!number)
 			number = numsubst;
 		pbx_builtin_setvar_helper(chan, "DIALEDPEERNUMBER", number);
+		ast_channel_unlock(peer);
+
 		if (!ast_strlen_zero(args.url) && ast_channel_supports_html(peer) ) {
 			ast_debug(1, "app_dial: sendurl=%s.\n", args.url);
 			ast_channel_sendurl( peer, args.url );
@@ -1722,7 +1752,10 @@
 				res = -1;
 			}
 
-			if (!res && (macro_result = pbx_builtin_getvar_helper(peer, "MACRO_RESULT"))) {
+			ast_channel_lock(peer);
+			macro_result = pbx_builtin_getvar_helper(peer, "MACRO_RESULT");
+
+			if (!res && (macro_result)) {
 				char *macro_transfer_dest;
 
 				if (!strcasecmp(macro_result, "BUSY")) {
@@ -1753,6 +1786,8 @@
 					}
 				}
 			}
+
+			ast_channel_unlock(peer);
 		}
 
 		if (ast_test_flag64(&opts, OPT_CALLEE_GOSUB) && !ast_strlen_zero(opt_args[OPT_ARG_CALLEE_GOSUB])) {
@@ -1804,8 +1839,11 @@
 				ast_log(LOG_ERROR, "Could not stop autoservice on calling channel\n");
 				res = -1;
 			}
+			
+			ast_channel_lock(peer);
+			gosub_result = pbx_builtin_getvar_helper(peer, "GOSUB_RESULT");
 
-			if (!res && (gosub_result = pbx_builtin_getvar_helper(peer, "GOSUB_RESULT"))) {
+			if (!res && (gosub_result)) {
 				char *gosub_transfer_dest;
 
 				if (!strcasecmp(gosub_result, "BUSY")) {
@@ -1836,6 +1874,8 @@
 					}
 				}
 			}
+
+			ast_channel_unlock(peer);	
 		}
 
 		if (!res) {
@@ -2023,7 +2063,8 @@
 	if (!loops)
 		loops = -1; /* run forever */
 
-	context = pbx_builtin_getvar_helper(chan, "EXITCONTEXT");
+	ast_channel_lock(chan);
+	context = pbx_builtin_getvar_helper(chan, "EXITCONTEXT"); 
 
 	res = 0;
 	while (loops) {
@@ -2078,6 +2119,7 @@
 		}
 		loops--;
 	}
+	ast_channel_unlock(chan);
 	if (loops == 0)
 		res = 0;
 	else if (res == 1)