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Date: Sat, 11 Sep 2010 18:15:45 -0400
Message-ID: <AANLkTikE2SkyyHYPepQGaRRUv8ymP6F5RSx3SXVcZXXH@mail.gmail.com>
Subject: Re: [9fans] email header screwup (and fix)
From: Russ Cox <rsc@swtch.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
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On Thu, Sep 9, 2010 at 4:13 PM, erik quanstrom <quanstro@quanstro.net> wrot=
e:
> lately, i've been seeing email with gigantic headers.
> 120 header lines are not that uncommon. =C2=A0unfortunately
> upas has sometimes inserts a blank line about
> (but not exactly) 4k into the file. =C2=A0a bit of digging, upas/send
> was assuming that if yacc didn't stop at a blank line, one should
> be inserted. unfortunately, yacc was stopping because it ran out of stack
> space. =C2=A0the hack is to increase YYMAXDEPTH. =C2=A0ideally,
> each line should be parsed independently, thus making
> yacc's depth depend only on the complexity of a line.

or change the grammar not to need unlimited stack space.
it says

fields		: '\n'
			{ yydone =3D 1; }
		| field '\n'
		| field '\n' fields
		;

but i think you can change it to

fields	: fieldlist '\n'
			{ yydone =3D 1; }
		;

fieldlist	:
		| fieldlist field '\n'
		;

russ