Bug #72625 [Csd]: realpath() fails on very long argument.

Edit report at https://bugs.php.net/bug.php?id=72625&edit=1 ID: 72625 Updated by: ab@php.net Reported by: anrdaemon at freemail dot ru Summary: realpath() fails on very long argument. Status: Closed Type: Bug Package: Filesystem function related Operating System: Windows PHP Version: 7.0.8 Assigned To: ab Block user comment: N Private report: N New Comment: Christoph, i've fixed this exact case, and also partially the general case using teh new APIs when available. Reimplementing the path canonicalization might take some time. The clean case is however worky under any circumstances. @anrdaemon just one note to your code - realpath(dirname($fn1)) seems wrong. If the path ends with some periods, it might deliver usexpected results. Thanks. Previous Comments: ------------------------------------------------------------------------ [2016-07-23 19:48:19] ab@php.net Automatic comment on behalf of ab Revision: http://git.php.net/?p=php-src.git;a=commit;h=0f16c56262a4d1f91bc299bb47d82df1e09700f8 Log: Fixed bug #72625 realpath() fails on non canonical long path ------------------------------------------------------------------------ [2016-07-23 16:17:10] ab@php.net @cmb, yeah, Windows API won't do any magic with \\?\ prefixed paths. I intentionally left this part, because there is yet no API for all windows versions (starting with 8.1 there is one). Also, that saves some memory operations. While replacing slashes wouldn't cost any memory overhead, so probably could be done. Since this issue is related to composer, probably worth it at least. I'll look to maybe come up with some custom PathCchCanonicalizeEx for lower Windows versions. Thanks. ------------------------------------------------------------------------ [2016-07-21 23:02:15] cmb@php.net The issue is FindFirstFileW(), which isn't as liberal with regard to the \\?\ prefix as without it. POC: #include <windows.h> int main() { HANDLE h; WIN32_FIND_DATA fd; h = FindFirstFileW(L"C:\\Windows", &fd); printf("%i\n", h != INVALID_HANDLE_VALUE); h = FindFirstFileW(L"C:/Windows", &fd); printf("%i\n", h != INVALID_HANDLE_VALUE); h = FindFirstFileW(L"\\\\?\\C:\\Windows", &fd); printf("%i\n", h != INVALID_HANDLE_VALUE); h = FindFirstFileW(L"\\\\?\\C:/Windows", &fd); printf("%i\n", h != INVALID_HANDLE_VALUE); return 0; } outputs: 1 1 1 0 Neither slashes (nor dots nor double-dots) are converted, as noted on MSDN in the section about "Maximum Path Length Limitation"[1]. It occurs to me that this conversion would have to be done by PHP in the first place. Anatol, what do you think? [1] <https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx#maxpath> ------------------------------------------------------------------------ [2016-07-21 18:43:01] cmb@php.net Indeed, can also reproduce with current master. ------------------------------------------------------------------------ [2016-07-21 12:07:02] anrdaemon at freemail dot ru Didn't change. If not made worse. Refined script: <?php $fn = "{$_SERVER['TEMP']}/_test/documents/projects/myproject/vendor/name/library/classpath"; $fn1 = "$fn/../../../../../../../../_test/documents/projects/myproject/vendor/name/library/../../../../../../../_test/documents/projects/myproject/vendor/name/library/classpath"; mkdir($fn, 0777, true); error_log(sprintf("(%u)%s", strlen($fn), $fn)); error_log("=>" . realpath($fn)); error_log(sprintf("(%u)%s", strlen($fn1), $fn1)); error_log("=>" . realpath($fn1)); error_log(sprintf("(%u)%s", strlen(dirname($fn1)), dirname($fn1))); error_log("=>" . realpath(dirname($fn1))); PHP 5.6.23/64 (101)C:\Users\ANRDAE~1\AppData\Local\Temp/_test/documents/projects/myproject/vendor/name/library/classpath =>C:\Users\anrdaemon\AppData\Local\Temp\_test\documents\projects\myproject\vendor\name\library\classpath (266)C:\Users\ANRDAE~1\AppData\Local\Temp/_test/documents/projects/myproject/vendor/name/library/classpath/../../../../../../../../_test/documents/projects/myproject/vendor/name/library/../../../../../../../_test/documents/projects/myproject/vendor/name/library/classpath => (256)C:\Users\ANRDAE~1\AppData\Local\Temp/_test/documents/projects/myproject/vendor/name/library/classpath/../../../../../../../../_test/documents/projects/myproject/vendor/name/library/../../../../../../../_test/documents/projects/myproject/vendor/name/library =>C:\Users\anrdaemon\AppData\Local\Temp\_test\documents\projects\myproject\vendor\name\library PHP 7.0.8/64 (101)C:\Users\ANRDAE~1\AppData\Local\Temp/_test/documents/projects/myproject/vendor/name/library/classpath =>C:\Users\anrdaemon\AppData\Local\Temp\_test\documents\projects\myproject\vendor\name\library\classpath (266)C:\Users\ANRDAE~1\AppData\Local\Temp/_test/documents/projects/myproject/vendor/name/library/classpath/../../../../../../../../_test/documents/projects/myproject/vendor/name/library/../../../../../../../_test/documents/projects/myproject/vendor/name/library/classpath => (256)C:\Users\ANRDAE~1\AppData\Local\Temp/_test/documents/projects/myproject/vendor/name/library/classpath/../../../../../../../../_test/documents/projects/myproject/vendor/name/library/../../../../../../../_test/documents/projects/myproject/vendor/name/library =>C:\Users\anrdaemon\AppData\Local\Temp\_test\documents\projects\myproject\vendor\name\library PHP 7.1.0b1/64 (101)C:\Users\ANRDAE~1\AppData\Local\Temp/_test/documents/projects/myproject/vendor/name/library/classpath =>C:\Users\anrdaemon\AppData\Local\Temp\_test\documents\projects\myproject\vendor\name\library\classpath (266)C:\Users\ANRDAE~1\AppData\Local\Temp/_test/documents/projects/myproject/vendor/name/library/classpath/../../../../../../../../_test/documents/projects/myproject/vendor/name/library/../../../../../../../_test/documents/projects/myproject/vendor/name/library/classpath => (260)\\?\C:\Users\ANRDAE~1\AppData\Local\Temp/_test/documents/projects/myproject/vendor/name/library/classpath/../../../../../../../../_test/documents/projects/myproject/vendor/name/library/../../../../../../../_test/documents/projects/myproject/vendor/name/library => ------------------------------------------------------------------------ The remainder of the comments for this report are too long. 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