http-backend: respect CONTENT_LENGTH for receive-pack

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>

1 files changed, 1 insertions, 0 deletions

diff --git a/help.c b/help.c
index dd35fcc133..e469f5731c 100644
--- a/help.c
+++ b/help.c
@@ -609,6 +609,7 @@ int cmd_version(int argc, const char **argv, const char *prefix)
 		else
 			printf("no commit associated with this build\n");
 		printf("sizeof-long: %d\n", (int)sizeof(long));
+		printf("sizeof-size_t: %d\n", (int)sizeof(size_t));
 		/* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
 	}
 	return 0;