Bug->Doc #75807 [Csd->Opn]: deflate_init fails with window bits set to 8

Edit report at https://bugs.php.net/bug.php?id=75807&edit=1 ID: 75807 Updated by: cmb@php.net Reported by: matt at bonneau dot net Summary: deflate_init fails with window bits set to 8 -Status: Closed +Status: Open -Type: Bug +Type: Documentation Problem Package: Zlib related PHP Version: master-Git-2018-01-12 (Git) -Assigned To: +Assigned To: cmb Block user comment: N Private report: N New Comment: This is more of a documentation issue; at least window size 8 is still supported for ZLIB_ENCODING_DEFLATE. Previous Comments: ------------------------------------------------------------------------ [2020-11-20 11:18:10] phpdocbot@php.net Automatic comment on behalf of cmb Revision: http://git.php.net/?p=doc/en.git;a=commit;h=5c818901d4f95ed211ecb3d476472cec1c739979 Log: Fix #78527: zlib deflate bug with windowBits == 8 Fix #75807: deflate_init fails with window bits set to 8 ------------------------------------------------------------------------ [2018-01-12 02:25:56] matt at bonneau dot net See: https://github.com/madler/zlib/commit/049578f0a1849f502834167e233f4c1d52ddcbcc "There is a bug in deflate for windowBits == 8 (256-byte window). As a result, zlib silently changes a request for 8 to a request for 9 (512-byte window), and sets the zlib header accordingly so that the decompressor knows to use a 512-byte window. However if deflateInit2() is used for raw deflate or gzip streams, then there is no indication that the request was not honored, and the application might assume that it can use a 256-byte window when decompressing. This commit returns an error if the user requests a 256-byte window when using raw deflate or gzip encoding." ------------------------------------------------------------------------ [2018-01-12 02:22:38] matt at bonneau dot net Output should actually be: Warning: deflate_init(): zlib window size (logarithm) (8) must be within 9..15 ------------------------------------------------------------------------ [2018-01-12 02:09:40] matt at bonneau dot net Description: ------------ Newer versions of zlib reject an 8 bit window. Minimum value should be changed to 9 instead of 8. This failure was noticed with zlib 1.2.8. Test script: --------------- <?php deflate_init( ZLIB_ENCODING_RAW, [ 'window' => 8, ] ); Expected result: ---------------- Expect no output. Actual result: -------------- Warning: deflate_init(): failed allocating zlib.deflate context in test3.php on line 5 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=75807&edit=1