debug_print_backtrace-limit.patch

Index: Zend/zend_builtin_functions.c
===================================================================
--- Zend/zend_builtin_functions.c	(revision 309942)
+++ Zend/zend_builtin_functions.c	(working copy)
@@ -2047,11 +2048,11 @@
 	}
 }
 
-/* {{{ proto void debug_print_backtrace([int options]) */
+/* {{{ proto void debug_print_backtrace([int options[, int limit]]) */
 ZEND_FUNCTION(debug_print_backtrace)
 {
 	zend_execute_data *ptr, *skip;
-	int lineno;
+	int lineno, frameno = 0;
 	char *function_name;
 	char *filename;
 	const char *class_name = NULL;
@@ -2060,8 +2061,9 @@
 	zval *arg_array = NULL;
 	int indent = 0;
 	long options = 0;
+	long limit = 0;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "|l", &options) == FAILURE) {
+	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "|ll", &options, &limit) == FAILURE) {
 		return;
 	}
 
@@ -2070,9 +2072,10 @@
 	/* skip debug_backtrace() */
 	ptr = ptr->prev_execute_data;
 
-	while (ptr) {
+	while (ptr && (limit == 0 || frameno < limit)) {
 		const char *free_class_name = NULL;
 
+		frameno++;
 		class_name = call_type = NULL;   
 		arg_array = NULL;
 
Index: Zend/tests/debug_print_backtrace_limit.phpt
===================================================================
--- Zend/tests/debug_print_backtrace_limit.phpt	(revision 0)
+++ Zend/tests/debug_print_backtrace_limit.phpt	(revision 0)
@@ -0,0 +1,31 @@
+--TEST--
+debug_print_backtrace limit
+--FILE--
+<?php
+function a() {
+    b();
+}
+
+function b() {
+    c();
+}
+
+function c() {
+    debug_print_backtrace(0, 1);
+    debug_print_backtrace(0, 2);
+    debug_print_backtrace(0, 0);
+    debug_print_backtrace(0, 4);
+}
+
+a();
+?>
+--EXPECTF--
+#0  c() called at [%s/debug_print_backtrace_limit.php:7]
+#0  c() called at [%s/debug_print_backtrace_limit.php:7]
+#1  b() called at [%s/debug_print_backtrace_limit.php:3]
+#0  c() called at [%s/debug_print_backtrace_limit.php:7]
+#1  b() called at [%s/debug_print_backtrace_limit.php:3]
+#2  a() called at [%s/debug_print_backtrace_limit.php:17]
+#0  c() called at [%s/debug_print_backtrace_limit.php:7]
+#1  b() called at [%s/debug_print_backtrace_limit.php:3]
+#2  a() called at [%s/debug_print_backtrace_limit.php:17]