rewriting config_*, xmalloc_fget*

[Denys Vlasenko]

On Thursday 16 June 2011 06:51, Timo Teräs wrote:
> >> Though, in bb config_* API, getdelim isn't always enough. They seem to
> >> need a special line reader that treats both \0 and \n as line terminator.
> > 
> > Why? \0 is not valid in text files and certainly shouldn't appear in
> > config files... What is it needed for?
> 
> Well, that's the way they just work upstream, and you get regression if
> you try to change it. I agree on that most applets do not need it, and
> might actually be sort of broken for treating \0 as new line now.
> 
> Notably, though, at least sed.c seems to rely on the fact that \n and \0
> are both recognized, and jumps through many hoops to handle them both
> properly. Apparently there's out some sed scripts that use both \n and
> \0 as statement separator, but they have different meaning.

sed does not use bb_get_chunk_with_continuation() directly.
It uses bb_get_chunk_from_file(), which is implemented with
bb_get_chunk_with_continuation().

bb_get_chunk_with_continuation() is used only by config parser,
and config parser definitely has no need to deal with \0.
Meaning: it needs to not segfault or hand on files with \0,
but other than this, it is free to either ignore \0, or replace
then with space or newline. IOW: whoever has \0 in their *config*
files is shooting himself in the foot.

The first step would be to unmarry these two functions.

> Not sure if there's other applets relying on this.
> 
> But just like I told before, this also reason why the API needs rewrite,
> it should *not* treat both as line separators, unless there's some
> explicit need.

bb_get_chunk_from_file() + sed is a can of worms. It needs cleaning up,
but any rewrite must at least pass all tests in testsuite current
implementation passes.

-- 
vda