view tests/test-mq-qgoto.t @ 26454:62c5e937f477

pager: recreate stdout to make it line-buffered

We want to see partial command results as soon as possible. But the buffering
mode of stdout (= pager's stdin) was set to fully-buffered because it isn't
associated with a tty. So, this patch recreates new stdout object to force its
buffering mode.

Because two file objects are associated with the same stdout fd and their
destructors will call close(), one of them must be closed carefully. Python
expects that the stdout fd never be closed even after sys.stdout.close() [1],
but newstdout has no such hack. So this patch calls newstdout.close()
immediately before duplicating the original stdout fd to sys.stdout.

  operation              sys.stdout  newstdout  fd
  ---------------------  ----------  ---------  --------
  newstdout.close()      open        closed     closed
  os.dup2(stdoutfd, ..)  open        closed     open
  del sys.stdout         closed      closed     open [1]

 [1]: https://hg.python.org/cpython/file/v2.7.10/Python/sysmodule.c#l1391

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init a
  $ cd a
  $ echo a > a
  $ hg ci -Ama
  adding a

  $ hg qnew a.patch
  $ echo a >> a
  $ hg qrefresh

  $ hg qnew b.patch
  $ echo b > b
  $ hg add b
  $ hg qrefresh

  $ hg qnew c.patch
  $ echo c > c
  $ hg add c
  $ hg qrefresh

  $ hg qgoto a.patch
  popping c.patch
  popping b.patch
  now at: a.patch

  $ hg qgoto c.patch
  applying b.patch
  applying c.patch
  now at: c.patch

  $ hg qgoto b.patch
  popping c.patch
  now at: b.patch

Using index:

  $ hg qgoto 0
  popping b.patch
  now at: a.patch

  $ hg qgoto 2
  applying b.patch
  applying c.patch
  now at: c.patch

No warnings when using index ... and update from non-qtip and with pending
changes in unrelated files:

  $ hg qnew bug314159
  $ echo d >> c
  $ hg qrefresh
  $ hg qnew bug141421
  $ echo e >> b
  $ hg qrefresh

  $ hg up -r bug314159
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo f >> a
  $ echo f >> b
  $ echo f >> c

  $ hg qgoto 1
  abort: local changes found, refresh first
  [255]
  $ hg qgoto 1 -f
  popping bug141421
  popping bug314159
  popping c.patch
  now at: b.patch
  $ hg st
  M a
  M b
  ? c.orig
  $ hg up -qCr.

  $ hg qgoto 3
  applying c.patch
  applying bug314159
  now at: bug314159

Detect ambiguous non-index:

  $ hg qgoto 14
  patch name "14" is ambiguous:
    bug314159
    bug141421
  abort: patch 14 not in series
  [255]

  $ cd ..