Question about windowBits=8

[cfg1234]

I set windowBits = 8 when calling deflateInit2_ ,which actually set to 9:

zlib/deflate.c

Line 297 in 04f42ce

if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */

The comment says there is bug when window size is 256 byte.
I notice that this comment was created over 10 years ago.
Why can't we fix it yet?

[madler]

"we"? Are you suggesting that you're going to fix it?

[cfg1234]

I'd like to, but I wonder why this bug has not been fixed for so long(Maybe it's a difficult job).So I need more information about this bug.

[cfg1234]

I found that MAX_DIST returns negative value when w_size < MIN_LOOKAHEAD:

zlib/deflate.h

Line 284 in 04f42ce

#define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)

When windowBits = 8, w_size = 256, then MAX_DIST return -6. It's an illegal distance.