tests/test-issue612.t

test-http-bad-server: introduce socket closing after reading a pattern

We introduce the `close-after-recv-patterns` option. It has the same goal as
`close-after-send-patterns` with a slightly different implementation.

Reading "up to a pattern" is hard. As we can only check the pattern from what we
have already read (inlike writing, were we can check what we are about to
write).

So instead we make the `close-after-recv-patterns` alter the behavior of the
existing `close-after-recv-bytes`. The value from `close-after-recv-bytes` only
gets into play after we have seen the pattern from `close-after-recv-patterns`.

This allow us to achieve the target benefit without changing the read pattern
too much.

Differential Revision: https://phab.mercurial-scm.org/D12068

https://bz.mercurial-scm.org/612

  $ hg init
  $ mkdir src
  $ echo a > src/a.c
  $ hg ci -Ama
  adding src/a.c

  $ hg mv src source
  moving src/a.c to source/a.c

  $ hg ci -Ammove

  $ hg co -C 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo new > src/a.c
  $ echo compiled > src/a.o
  $ hg ci -mupdate
  created new head

  $ hg status
  ? src/a.o

  $ hg merge
  merging src/a.c and source/a.c to source/a.c
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg status
  M source/a.c
  R src/a.c
  ? src/a.o