Index: include/asterisk/pbx.h
===================================================================
--- include/asterisk/pbx.h	(revision 112321)
+++ include/asterisk/pbx.h	(working copy)
@@ -42,6 +42,7 @@
 #define AST_PBX_ERROR	        1	/*!< Jump to the 'e' exten */
 #define AST_PBX_KEEPALIVE	10	/*!< Destroy the thread, but don't hang up the channel */
 #define AST_PBX_NO_HANGUP_PEER	11
+#define AST_PBX_INCOMPLETE	12	/*!< Return to PBX matching, allowing more digits for the extension */
 /*! } */
 
 #define PRIORITY_HINT	-1	/*!< Special Priority for a hint */
Index: main/pbx.c
===================================================================
--- main/pbx.c	(revision 112321)
+++ main/pbx.c	(working copy)
@@ -302,6 +302,7 @@
 static int pbx_builtin_background(struct ast_channel *, void *);
 static int pbx_builtin_wait(struct ast_channel *, void *);
 static int pbx_builtin_waitexten(struct ast_channel *, void *);
+static int pbx_builtin_incomplete(struct ast_channel *, void *);
 static int pbx_builtin_keepalive(struct ast_channel *, void *);
 static int pbx_builtin_resetcdr(struct ast_channel *, void *);
 static int pbx_builtin_setamaflags(struct ast_channel *, void *);
@@ -579,6 +580,23 @@
 	"value.\n"
 	},
 
+	{ "Incomplete", pbx_builtin_incomplete,
+	"returns AST_PBX_INCOMPLETE value",
+	"  Incomplete([n]): Signals the PBX routines that the previous matched extension\n"
+	"is incomplete and that further input should be allowed before matching can\n"
+	"be considered to be complete.  Can be used within a pattern match when\n"
+	"certain criteria warrants a longer match.\n"
+	"  If the 'n' option is specified, then Incomplete will not attempt to answer\n"
+	"the channel first.  Note that most channel types need to be in Answer state\n"
+	"in order to receive DTMF.\n"
+	},
+
+	{ "KeepAlive", pbx_builtin_keepalive,
+	"returns AST_PBX_KEEPALIVE value",
+	"  KeepAlive(): This application is chiefly meant for internal use with Gosubs.\n"
+	"Please do not run it alone from the dialplan!\n"
+	},
+
 	{ "NoOp", pbx_builtin_noop,
 	"Do Nothing (No Operation)",
 	"  NoOp(): This application does nothing. However, it is useful for debugging\n"
@@ -696,12 +714,6 @@
 	"See Also: Playback(application), Background(application).\n"
 	},
 
-	{ "KeepAlive", pbx_builtin_keepalive,
-	"returns AST_PBX_KEEPALIVE value",
-	"  KeepAlive(): This application is chiefly meant for internal use with Gosubs.\n"
-	"Please do not run it alone from the dialplan!\n"
-	},
-
 };
 
 static struct ast_context *contexts;
@@ -3572,6 +3584,19 @@
 				ast_debug(1, "Spawn extension (%s,%s,%d) exited KEEPALIVE on '%s'\n", c->context, c->exten, c->priority, c->name);
 				ast_verb(2, "Spawn extension (%s, %s, %d) exited KEEPALIVE on '%s'\n", c->context, c->exten, c->priority, c->name);
 				error = 1;
+			} else if (res == AST_PBX_INCOMPLETE) {
+				ast_debug(1, "Spawn extension (%s,%s,%d) exited INCOMPLETE on '%s'\n", c->context, c->exten, c->priority, c->name);
+				ast_verb(2, "Spawn extension (%s, %s, %d) exited INCOMPLETE on '%s'\n", c->context, c->exten, c->priority, c->name);
+
+				/* Don't cycle on incomplete - this will happen if the only extension that matches is our "incomplete" extension */
+				if (!ast_matchmore_extension(c, c->context, c->exten, c->priority, c->cid.cid_num)) {
+					pbx_builtin_setvar_helper(c, "INVALID_EXTEN", c->exten);
+					ast_copy_string(c->exten, "i", sizeof(c->exten));
+				} else {
+					ast_copy_string(dst_exten, c->exten, sizeof(dst_exten));
+					digit = 1;
+					pos = strlen(dst_exten);
+				}
 			} else {
 				ast_debug(1, "Spawn extension (%s,%s,%d) exited non-zero on '%s'\n", c->context, c->exten, c->priority, c->name);
 				ast_verb(2, "Spawn extension (%s, %s, %d) exited non-zero on '%s'\n", c->context, c->exten, c->priority, c->name);
@@ -7313,6 +7338,26 @@
 	return AST_PBX_KEEPALIVE;
 }
 
+static int pbx_builtin_incomplete(struct ast_channel *chan, void *data)
+{
+	char *options = data;
+	int answer = 1;
+
+	/* Some channels can receive DTMF in unanswered state; some cannot */
+	if (!ast_strlen_zero(options) && strchr(options, 'n')) {
+		answer = 0;
+	}
+
+	/* If the channel is hungup, stop waiting */
+	if (ast_check_hangup(chan)) {
+		return -1;
+	} else if (chan->_state != AST_STATE_UP && answer) {
+		__ast_answer(chan, 0);
+	}
+
+	return AST_PBX_INCOMPLETE;
+}
+
 AST_APP_OPTIONS(resetcdr_opts, {
 	AST_APP_OPTION('w', AST_CDR_FLAG_POSTED),
 	AST_APP_OPTION('a', AST_CDR_FLAG_LOCKED),