Push passes to another commands, as described in
https://public-inbox.org/git/20171129032214.GB32345@sigill.intra.peff.net/
As it gets complicated to correctly track the data length, instead transfer
the data through parent process and cut the pipe as the specified length is
reached. Do it only when CONTENT_LENGTH is set, otherwise pass the input
directly to the forked commands.
Add tests for cases:
* CONTENT_LENGTH is set, script's stdin has more data, with all combinations
of variations: fetch or push, plain or compressed body, correct or truncated
input.
* CONTENT_LENGTH is specified to a value which does not fit into ssize_t.
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Max Kirillov <max@max630.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
6c213e863a