Bug #81145 [Asn->Ana]: copy() and stream_copy_to_stream() fail for +4GB files

Edit report at https://bugs.php.net/bug.php?id=81145&edit=1 ID: 81145 Updated by: cmb@php.net Reported by: php at bitm dot sg Summary: copy() and stream_copy_to_stream() fail for +4GB files -Status: Assigned +Status: Analyzed Type: Bug Package: Filesystem function related Operating System: Windows 10.0.19042.985 x64 -PHP Version: 8.0.7 +PHP Version: 7.4 Assigned To: cmb Block user comment: N Private report: N New Comment: Confirmed (affects PHP-7.4 on Windows as well). Thanks for the helpful analysis on reddit[1]. [1] <https://www.reddit.com/r/PHP/comments/o0oqhg/problems_copying_large_files/h1y9a5t/> Previous Comments: ------------------------------------------------------------------------ [2021-06-16 10:14:09] php at bitm dot sg Fixed the Windows version because it was cut off. ------------------------------------------------------------------------ [2021-06-16 09:56:11] nikic@php.net Seems to work fine on Linux. ------------------------------------------------------------------------ [2021-06-16 09:43:27] php at bitm dot sg Description: ------------ Using copy() or stream_copy_to_stream() fails on Windows with files over 4GB, even if the underlying volume (NTFS) supports it and Windows + PHP are 64 bit. Test script: --------------- <?php //Both files must be on an NTFS volume. You may use the same volume. $src='C:/temp/4G.src.bin'; $dst='C:/temp/4G.dst.bin'; define('SIZE_4G',0x100000000); @unlink($src); //Create file and append random content at the 4GB boundary exec('fsutil file createnew ' . escapeshellarg($src) . ' ' . (SIZE_4G-0x100)); $fp=fopen($src,'ab'); fwrite($fp,random_bytes(0x200)); fclose($fp); copy($src,$dst); if(filesize($src)!==filesize($dst)){die('Files have different sizes!');} $f1=fopen($src,'rb') or die('src open failed'); $f2=fopen($dst,'rb') or die('dst open failed'); //Seek to 4 GB boundary, as this is the location where the problem occurs fseek($f1,SIZE_4G-0x100,SEEK_SET); fseek($f2,SIZE_4G-0x100,SEEK_SET); echo (fread($f1,0x200)===fread($f2,0x200)?'Identical':'Copy failed'); fclose($f1); fclose($f2); Expected result: ---------------- The functions should copy files and streams as-is and the script should print "Identical" Actual result: -------------- Script prints "Copy failed" Only the first 4 GB of the source file are copied. This is actually done repeatedly until the destination is as large as the source. So if the file is 13 GB, the destination will contain the first 4 GB of the source 3 times, followed by the first GB again. using "fwrite($b,fread($a,$buffer))" to manually copy files works. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=81145&edit=1