Fix both app_read and underlying read issue (bug #2352)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@3711 65c4cc65-6c06-0410-ace0-fbb531ad65f3

app.c

@@ -37,6 +37,8 @@ int ast_app_getdata(struct ast_channel *c, char *prompt, char *s, int maxlen, in
 {
 	int res,to,fto;
 	/* XXX Merge with full version? XXX */
+	if (maxlen)
+		s[0] = '\0';
 	if (prompt) {
 		res = ast_streamfile(c, prompt, c->language);
 		if (res < 0)

apps/app_read.c

@@ -103,9 +103,12 @@ static int read_exec(struct ast_channel *chan, void *data)
 	if (!res) {
 		ast_stopstream(chan);
 		res = ast_app_getdata(chan, filename, tmp, maxdigits, 0);
-		if (res > -1)
+		if (res > -1) {
 			pbx_builtin_setvar_helper(chan, varname, tmp);
-		ast_verbose(VERBOSE_PREFIX_3 "User entered '%s'\n", tmp);
+			ast_verbose(VERBOSE_PREFIX_3 "User entered '%s'\n", tmp);
+		} else {
+			ast_verbose(VERBOSE_PREFIX_3 "User entered nothing\n");
+		}
 	}
 	LOCAL_USER_REMOVE(u);
 	return res;