Re: [Lynx-dev] Weird colors on 'A view from the bridge' columns @nature.com

[Thomas Dickey]

On Thu, Aug 24, 2017 at 01:41:07PM -0600, address@hidden wrote:
>       Quoth Mr Thomas E. Dickey: 'I'd guess that the very-long class
> string causes lynx to provide the color...'
>       Do you mean that they overflow a variable, causing spurious
> results?  It comes up in foreground and background colors so similar I

no - there's no buffer overflow, but a hash-collision.  The color-style
code computes a hash-code for each of the listed styles, and is using
both the tag-name and classes to compute a hash-code to match.  Here's
a slice of the trace on a much-reduced test-case:

(during initialization)

LSS:li.red:reverse:red:yellow
parse_style(li.red:reverse:red:yellow)
CSSPARSE:li.red => 4648 
CSS(PA):style d=141 / h=4648, e=li.red
check_color(yellow,-1)
=> 11
check_color(red,-1)
=> 1
parse_attributes 1/-1 11/-1 0
CSS(CURPAIR):17
CSS(SET): <li.red> hash=4648, ca=0x1100, ma=0x40000

(the element you're interested in)

STYLE.start_element: <DIV>.<hentry wpn-post wpn-publish wpn-post-1 wpn-odd 
wpn-author-barbara-kiser wpn-has-excerpt wpn-category-arts 
wpn-category-lab-life wpn-category-physics wpn-category-psychology>, hcode=4648.

-- 
Thomas E. Dickey <address@hidden>
http://invisible-island.net
ftp://ftp.invisible-island.net

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