Accept null lengths for substr functions()

If a null $length is passed to any of these functions, behave as if no
parameter was passed:

 - substr()
 - substr_count()
 - substr_compare()
 - iconv_substr()

4 files changed, 9 insertions, 5 deletions

diff --git a/ext/iconv/iconv.c b/ext/iconv/iconv.c
index 9fab00a746..9e4c52d252 100644
--- a/ext/iconv/iconv.c
+++ b/ext/iconv/iconv.c
@@ -2028,13 +2028,14 @@ PHP_FUNCTION(iconv_substr)
 	size_t charset_len = 0;
 	zend_string *str;
 	zend_long offset, length = 0;
+	zend_bool len_is_null = 1;
 
 	php_iconv_err_t err;
 
 	smart_str retval = {0};
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "Sl|ls",
-		&str, &offset, &length,
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "Sl|l!s",
+		&str, &offset, &length, &len_is_null,
 		&charset, &charset_len) == FAILURE) {
 		return;
 	}
@@ -2044,7 +2045,7 @@ PHP_FUNCTION(iconv_substr)
 		RETURN_FALSE;
 	}
 
-	if (ZEND_NUM_ARGS() < 3) {
+	if (len_is_null) {
 		length = ZSTR_LEN(str);
 	}
 
diff --git a/ext/iconv/iconv.stub.php b/ext/iconv/iconv.stub.php
index dfa2593f0c..965c4a7e96 100644
--- a/ext/iconv/iconv.stub.php
+++ b/ext/iconv/iconv.stub.php
@@ -4,7 +4,7 @@
 function iconv_strlen(string $str, string $charset = UNKNOWN) {}
 
 /** @return string|false */
-function iconv_substr(string $str, int $offset, int $length = UNKNOWN, string $charset = UNKNOWN) {}
+function iconv_substr(string $str, int $offset, ?int $length = null, string $charset = UNKNOWN) {}
 
 /** @return int|false */
 function iconv_strpos(string $haystack, string $needle, int $offset = 0, string $charset = UNKNOWN) {}
diff --git a/ext/iconv/iconv_arginfo.h b/ext/iconv/iconv_arginfo.h
index 1587b0fadb..462b1cfbe4 100644
--- a/ext/iconv/iconv_arginfo.h
+++ b/ext/iconv/iconv_arginfo.h
@@ -8,7 +8,7 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_INFO_EX(arginfo_iconv_substr, 0, 0, 2)
 	ZEND_ARG_TYPE_INFO(0, str, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO(0, offset, IS_LONG, 0)
-	ZEND_ARG_TYPE_INFO(0, length, IS_LONG, 0)
+	ZEND_ARG_TYPE_INFO(0, length, IS_LONG, 1)
 	ZEND_ARG_TYPE_INFO(0, charset, IS_STRING, 0)
 ZEND_END_ARG_INFO()
 
diff --git a/ext/iconv/tests/iconv_substr.phpt b/ext/iconv/tests/iconv_substr.phpt
index 6ca545b2ea..2a514e6f61 100644
--- a/ext/iconv/tests/iconv_substr.phpt
+++ b/ext/iconv/tests/iconv_substr.phpt
@@ -34,6 +34,7 @@ foo("あいうえおかきくけこさしす", 5, 7, "EUC-JP");
 bar("This is a test", 100000);
 bar("This is a test", 0, 100000);
 bar("This is a test", -3);
+bar("This is a test", -3, null);
 bar("This is a test", 0, -9);
 bar("This is a test", 0, -100000);
 bar("This is a test", -9, -100000);
@@ -50,6 +51,8 @@ string(14) "This is a test"
 string(14) "This is a test"
 string(3) "est"
 string(3) "est"
+string(3) "est"
+string(3) "est"
 string(5) "This "
 string(5) "This "
 bool(false)