view tests/test-issue1877.t @ 16367:c14898df3b92 stable

ui: swallow EBADF on stderr

ui.write_err already swallows EPIPE and EIO if a write to stderr fails.
On Mac OS X at least, a write to a closed file descriptor results in
EBADF. Before this patch, hg would exit with status 1 if a write to
stderr failed during startup (e.g. while trying to print a warning about
not finding an extension):

  $ ./hg --config extensions.foo= version 2>&-; echo $?
  1

With this patch, it correctly swallows stderr and continues to run the
command:

  $ ./hg --config extensions.foo= version 2>&-
  Mercurial Distributed SCM (version 2.1)
  ...

http://mercurial.selenic.com/bts/issue1877

  $ hg init a
  $ cd a
  $ echo a > a
  $ hg add a
  $ hg ci -m 'a'
  $ echo b > a
  $ hg ci -m'b'
  $ hg up 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg book main
  $ hg book
   * main                      0:cb9a9f314b8b
  $ echo c > c
  $ hg add c
  $ hg ci -m'c'
  created new head
  $ hg book
   * main                      2:d36c0562f908
  $ hg heads
  changeset:   2:d36c0562f908
  bookmark:    main
  tag:         tip
  parent:      0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     c
  
  changeset:   1:1e6c11564562
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b
  
  $ hg up 1e6c11564562
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge main
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg book
     main                      2:d36c0562f908
  $ hg ci -m'merge'
  $ hg book
     main                      2:d36c0562f908