Bug #79410 [PATCH]: system() swallows last chunk if it is exactly 4095 bytes without newline

Edit report at https://bugs.php.net/bug.php?id=79410&edit=1 ID: 79410 Patch added by: cmb@php.net Reported by: cschneid@php.net Summary: system() swallows last chunk if it is exactly 4095 bytes without newline Status: Verified Type: Bug Package: Program Execution Operating System: * PHP Version: Irrelevant Block user comment: N Private report: N New Comment: The following pull request has been associated: Patch Name: Fix Bug #79410 and add test for it On GitHub: https://github.com/php/php-src/pull/5292 Patch: https://github.com/php/php-src/pull/5292.patch Previous Comments: ------------------------------------------------------------------------ [2020-03-23 20:41:35] cschneid@php.net Description: ------------ When executing a program where the output's last chunk is 4095 bytes then the last chunk is swallowed. The script below generates 4095 dots on Linux and counts how many system()'s output contain. None of the dots reach the output, a patch resolving this issue is attached. The bug could already be reproduced in 5.3.0, I did not trace it back farther than that. Test script: --------------- # Execute command print 4095 dots php -r 'system("printf .%.0s {1..4095}");' | wc -c Expected result: ---------------- 4095 Actual result: -------------- 0 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79410&edit=1