From f5994494aca9e592047474efc05deb31b6789d0d Mon Sep 17 00:00:00 2001
From: "Christoph M. Becker" <cmbecker69@gmx.de>
Date: Fri, 22 Jan 2021 13:08:51 +0100
Subject: [PATCH] Fix #53251: bindtextdomain with null dir doesn't return old
 value

Apparently, users expect `bindtextdomain` and `bind_textdomain_codeset`
with `null` as second argument to work like their C counterparts,
namely to return the previously set value.  Thus, we support that.
---
 ext/gettext/gettext.c           | 12 ++++++++----
 ext/gettext/tests/bug53251.phpt | 23 +++++++++++++++++++++++
 2 files changed, 31 insertions(+), 4 deletions(-)
 create mode 100644 ext/gettext/tests/bug53251.phpt

diff --git a/ext/gettext/gettext.c b/ext/gettext/gettext.c
index 003787f5c08b4..f68057925995e 100644
--- a/ext/gettext/gettext.c
+++ b/ext/gettext/gettext.c
@@ -255,11 +255,11 @@ PHP_NAMED_FUNCTION(zif_dcgettext)
    Bind to the text domain domain_name, looking for translations in dir. Returns the current domain */
 PHP_NAMED_FUNCTION(zif_bindtextdomain)
 {
-	char *domain, *dir;
+	char *domain, *dir = NULL;
 	size_t domain_len, dir_len;
 	char *retval, dir_name[MAXPATHLEN];
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "ss", &domain, &domain_len, &dir, &dir_len) == FAILURE) {
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "ss!", &domain, &domain_len, &dir, &dir_len) == FAILURE) {
 		return;
 	}
 
@@ -270,6 +270,10 @@ PHP_NAMED_FUNCTION(zif_bindtextdomain)
 		RETURN_FALSE;
 	}
 
+	if (dir == NULL) {
+		RETURN_STRING(bindtextdomain(domain, NULL));
+	}
+
 	if (dir[0] != '\0' && strcmp(dir, "0")) {
 		if (!VCWD_REALPATH(dir, dir_name)) {
 			RETURN_FALSE;
@@ -368,10 +372,10 @@ PHP_NAMED_FUNCTION(zif_dcngettext)
    Specify the character encoding in which the messages from the DOMAIN message catalog will be returned. */
 PHP_NAMED_FUNCTION(zif_bind_textdomain_codeset)
 {
-	char *domain, *codeset, *retval = NULL;
+	char *domain, *codeset = NULL, *retval = NULL;
 	size_t domain_len, codeset_len;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "ss", &domain, &domain_len, &codeset, &codeset_len) == FAILURE) {
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "ss!", &domain, &domain_len, &codeset, &codeset_len) == FAILURE) {
 		return;
 	}
 
diff --git a/ext/gettext/tests/bug53251.phpt b/ext/gettext/tests/bug53251.phpt
new file mode 100644
index 0000000000000..b3e2e9e66c00f
--- /dev/null
+++ b/ext/gettext/tests/bug53251.phpt
@@ -0,0 +1,23 @@
+--TEST--
+Bug #53251 (bindtextdomain with null dir doesn't return old value)
+--SKIPIF--
+<?php
+if (!extension_loaded('gettext')) die('skip gettext extension not available');
+?>
+--FILE--
+<?php
+var_dump(is_string(bindtextdomain('foo', null)));
+$dir = bindtextdomain('foo', '.');
+var_dump(bindtextdomain('foo', null) === $dir);
+
+var_dump(bind_textdomain_codeset('foo', null));
+var_dump(bind_textdomain_codeset('foo', 'UTF-8'));
+var_dump(bind_textdomain_codeset('foo', null));
+
+?>
+--EXPECT--
+bool(true)
+bool(true)
+bool(false)
+string(5) "UTF-8"
+string(5) "UTF-8"