Fix GH-10521: ftp_get/ftp_nb_get resumepos offset is maximum 10GB

The char arrays were too small for a long on 64-bit systems, which
resulted in cutting off the string at the end with a NUL byte. Use a
size of MAX_LENGTH_OF_LONG to fix this issue instead of a fixed size
of 11 chars.

Author: nielsdos

ext/ftp/ftp.c

@@ -867,7 +867,7 @@ ftp_get(ftpbuf_t *ftp, php_stream *outstream, const char *path, const size_t pat
 {
 	databuf_t		*data = NULL;
 	size_t			rcvd;
-	char			arg[11];
+	char			arg[MAX_LENGTH_OF_LONG];
 
 	if (ftp == NULL) {
 		return 0;
@@ -964,7 +964,7 @@ ftp_put(ftpbuf_t *ftp, const char *path, const size_t path_len, php_stream *inst
 	zend_long			size;
 	char			*ptr;
 	int			ch;
-	char			arg[11];
+	char			arg[MAX_LENGTH_OF_LONG];
 
 	if (ftp == NULL) {
 		return 0;
@@ -2057,7 +2057,7 @@ int
 ftp_nb_get(ftpbuf_t *ftp, php_stream *outstream, const char *path, const size_t path_len, ftptype_t type, zend_long resumepos)
 {
 	databuf_t		*data = NULL;
-	char			arg[11];
+	char			arg[MAX_LENGTH_OF_LONG];
 
 	if (ftp == NULL) {
 		return PHP_FTP_FAILED;
@@ -2176,7 +2176,7 @@ int
 ftp_nb_put(ftpbuf_t *ftp, const char *path, const size_t path_len, php_stream *instream, ftptype_t type, zend_long startpos)
 {
 	databuf_t		*data = NULL;
-	char			arg[11];
+	char			arg[MAX_LENGTH_OF_LONG];
 
 	if (ftp == NULL) {
 		return 0;

ext/ftp/tests/gh10521.phpt

@@ -0,0 +1,39 @@
+--TEST--
+GH-10521 (ftp_get/ftp_nb_get resumepos offset is maximum 10GB)
+--EXTENSIONS--
+ftp
+pcntl
+--SKIPIF--
+<?php
+if (PHP_INT_SIZE != 8) die("skip: 64-bit only");
+?>
+--FILE--
+<?php
+require 'server.inc';
+
+$ftp = ftp_connect('127.0.0.1', $port);
+if (!$ftp) die("Couldn't connect to the server");
+
+var_dump(ftp_login($ftp, 'anonymous', 'IEUser@'));
+
+$local_file = __DIR__ . DIRECTORY_SEPARATOR . "gh10521.txt";
+
+foreach ([12345678910, 9223372036854775807] as $size) {
+    @unlink($local_file);
+    $handle = fopen($local_file, 'a');
+    var_dump(ftp_fget($ftp, $handle, 'fget_large.txt', FTP_ASCII, $size));
+    fclose($handle);
+    var_dump(file_get_contents($local_file));
+}
+
+?>
+--CLEAN--
+<?php
+@unlink(__DIR__ . DIRECTORY_SEPARATOR . "gh10521.txt");
+?>
+--EXPECT--
+bool(true)
+bool(true)
+string(11) "12345678910"
+bool(true)
+string(19) "9223372036854775807"

ext/ftp/tests/server.inc

@@ -371,6 +371,10 @@ if ($pid) {
                     $transfer_type = $ascii? 'ASCII' : 'BINARY' ;
                     if ($GLOBALS['rest_pos'] == '5368709119') {
                         fputs($fs, "X");
+                    } elseif ($GLOBALS['rest_pos'] == '12345678910') {
+                        fputs($fs, "12345678910");
+                    } elseif ($GLOBALS['rest_pos'] == '9223372036854775807') {
+                        fputs($fs, "9223372036854775807");
                     } else {
                         fputs($fs, "Y");
                     }