tests/test-automv.t

util: add iterfile to workaround a fileobj.__iter__ issue with EINTR

The fileobj.__iter__ implementation in Python 2.7.12 (hg changeset
45d4cea97b04) is buggy: it cannot handle EINTR correctly.

In Objects/fileobject.c:

    size_t Py_UniversalNewlineFread(....) {
        ....
        if (!f->f_univ_newline)
            return fread(buf, 1, n, stream);
        ....
    }

According to the "fread" man page:

    If an error occurs, or the end of the file is reached, the return value
    is a short item count (or zero).

Therefore it's possible for "fread" (and "Py_UniversalNewlineFread") to
return a positive value while errno is set to EINTR and ferror(stream)
changes from zero to non-zero.

There are multiple "Py_UniversalNewlineFread": "file_read", "file_readinto",
"file_readlines", "readahead". While the first 3 have code to handle the
EINTR case, the last one "readahead" doesn't:

    static int readahead(PyFileObject *f, Py_ssize_t bufsize) {
        ....
        chunksize = Py_UniversalNewlineFread(
            f->f_buf, bufsize, f->f_fp, (PyObject *)f);
        ....
        if (chunksize == 0) {
            if (ferror(f->f_fp)) {
                PyErr_SetFromErrno(PyExc_IOError);
                ....
            }
        }
        ....
    }

It means "readahead" could ignore EINTR, if "Py_UniversalNewlineFread"
returns a non-zero value. And at the next time "readahead" got executed, if
"Py_UniversalNewlineFread" returns 0, "readahead" would raise a Python error
without a incorrect errno - could be 0 - thus "IOError: [Errno 0] Error".

The only user of "readahead" is "readahead_get_line_skip".
The only user of "readahead_get_line_skip" is "file_iternext", aka.
"fileobj.__iter__", which should be avoided.

There are multiple places where the pattern "for x in fp" is used. This
patch adds a "iterfile" method in "util.py" so we can migrate our code from
"for x in fp" to "fox x in util.iterfile(fp)".

Tests for the automv extension; detect moved files at commit time.

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > automv=
  > rebase=
  > EOF

Setup repo

  $ hg init repo
  $ cd repo

Test automv command for commit

  $ printf 'foo\nbar\nbaz\n' > a.txt
  $ hg add a.txt
  $ hg commit -m 'init repo with a'

mv/rm/add
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg add b.txt
  $ hg status -C
  A b.txt
  R a.txt
  $ hg commit -m 'msg'
  detected move of 1 files
  $ hg status --change . -C
  A b.txt
    a.txt
  R a.txt
  $ hg up -r 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

mv/rm/add/modif
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg add b.txt
  $ printf '\n' >> b.txt
  $ hg status -C
  A b.txt
  R a.txt
  $ hg commit -m 'msg'
  detected move of 1 files
  created new head
  $ hg status --change . -C
  A b.txt
    a.txt
  R a.txt
  $ hg up -r 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

mv/rm/add/modif
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg add b.txt
  $ printf '\nfoo\n' >> b.txt
  $ hg status -C
  A b.txt
  R a.txt
  $ hg commit -m 'msg'
  created new head
  $ hg status --change . -C
  A b.txt
  R a.txt
  $ hg up -r 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

mv/rm/add/modif/changethreshold
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg add b.txt
  $ printf '\nfoo\n' >> b.txt
  $ hg status -C
  A b.txt
  R a.txt
  $ hg commit --config automv.similarity='60' -m 'msg'
  detected move of 1 files
  created new head
  $ hg status --change . -C
  A b.txt
    a.txt
  R a.txt
  $ hg up -r 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

mv
  $ mv a.txt b.txt
  $ hg status -C
  ! a.txt
  ? b.txt
  $ hg commit -m 'msg'
  nothing changed (1 missing files, see 'hg status')
  [1]
  $ hg status -C
  ! a.txt
  ? b.txt
  $ hg revert -aqC
  $ rm b.txt

mv/rm/add/notincommitfiles
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg add b.txt
  $ echo 'bar' > c.txt
  $ hg add c.txt
  $ hg status -C
  A b.txt
  A c.txt
  R a.txt
  $ hg commit c.txt -m 'msg'
  created new head
  $ hg status --change . -C
  A c.txt
  $ hg status -C
  A b.txt
  R a.txt
  $ hg up -r 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg rm a.txt
  $ echo 'bar' > c.txt
  $ hg add c.txt
  $ hg commit -m 'msg'
  detected move of 1 files
  created new head
  $ hg status --change . -C
  A b.txt
    a.txt
  A c.txt
  R a.txt
  $ hg up -r 0
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved

mv/rm/add/--no-automv
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg add b.txt
  $ hg status -C
  A b.txt
  R a.txt
  $ hg commit --no-automv -m 'msg'
  created new head
  $ hg status --change . -C
  A b.txt
  R a.txt
  $ hg up -r 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

Test automv command for commit --amend

mv/rm/add
  $ echo 'c' > c.txt
  $ hg add c.txt
  $ hg commit -m 'revision to amend to'
  created new head
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg add b.txt
  $ hg status -C
  A b.txt
  R a.txt
  $ hg commit --amend -m 'amended'
  detected move of 1 files
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-amend-backup.hg (glob)
  $ hg status --change . -C
  A b.txt
    a.txt
  A c.txt
  R a.txt
  $ hg up -r 0
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved

mv/rm/add/modif
  $ echo 'c' > c.txt
  $ hg add c.txt
  $ hg commit -m 'revision to amend to'
  created new head
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg add b.txt
  $ printf '\n' >> b.txt
  $ hg status -C
  A b.txt
  R a.txt
  $ hg commit --amend -m 'amended'
  detected move of 1 files
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-amend-backup.hg (glob)
  $ hg status --change . -C
  A b.txt
    a.txt
  A c.txt
  R a.txt
  $ hg up -r 0
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved

mv/rm/add/modif
  $ echo 'c' > c.txt
  $ hg add c.txt
  $ hg commit -m 'revision to amend to'
  created new head
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg add b.txt
  $ printf '\nfoo\n' >> b.txt
  $ hg status -C
  A b.txt
  R a.txt
  $ hg commit --amend -m 'amended'
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-amend-backup.hg (glob)
  $ hg status --change . -C
  A b.txt
  A c.txt
  R a.txt
  $ hg up -r 0
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved

mv/rm/add/modif/changethreshold
  $ echo 'c' > c.txt
  $ hg add c.txt
  $ hg commit -m 'revision to amend to'
  created new head
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg add b.txt
  $ printf '\nfoo\n' >> b.txt
  $ hg status -C
  A b.txt
  R a.txt
  $ hg commit --amend --config automv.similarity='60' -m 'amended'
  detected move of 1 files
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-amend-backup.hg (glob)
  $ hg status --change . -C
  A b.txt
    a.txt
  A c.txt
  R a.txt
  $ hg up -r 0
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved

mv
  $ echo 'c' > c.txt
  $ hg add c.txt
  $ hg commit -m 'revision to amend to'
  created new head
  $ mv a.txt b.txt
  $ hg status -C
  ! a.txt
  ? b.txt
  $ hg commit --amend -m 'amended'
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-amend-backup.hg (glob)
  $ hg status -C
  ! a.txt
  ? b.txt
  $ hg up -Cr 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

mv/rm/add/notincommitfiles
  $ echo 'c' > c.txt
  $ hg add c.txt
  $ hg commit -m 'revision to amend to'
  created new head
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg add b.txt
  $ echo 'bar' > d.txt
  $ hg add d.txt
  $ hg status -C
  A b.txt
  A d.txt
  R a.txt
  $ hg commit --amend -m 'amended' d.txt
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-amend-backup.hg (glob)
  $ hg status --change . -C
  A c.txt
  A d.txt
  $ hg status -C
  A b.txt
  R a.txt
  $ hg commit --amend -m 'amended'
  detected move of 1 files
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-amend-backup.hg (glob)
  $ hg status --change . -C
  A b.txt
    a.txt
  A c.txt
  A d.txt
  R a.txt
  $ hg up -r 0
  1 files updated, 0 files merged, 3 files removed, 0 files unresolved

mv/rm/add/--no-automv
  $ echo 'c' > c.txt
  $ hg add c.txt
  $ hg commit -m 'revision to amend to'
  created new head
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg add b.txt
  $ hg status -C
  A b.txt
  R a.txt
  $ hg commit --amend -m 'amended' --no-automv
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-amend-backup.hg (glob)
  $ hg status --change . -C
  A b.txt
  A c.txt
  R a.txt
  $ hg up -r 0
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved

mv/rm/commit/add/amend
  $ echo 'c' > c.txt
  $ hg add c.txt
  $ hg commit -m 'revision to amend to'
  created new head
  $ mv a.txt b.txt
  $ hg rm a.txt
  $ hg status -C
  R a.txt
  ? b.txt
  $ hg commit -m "removed a"
  $ hg add b.txt
  $ hg commit --amend -m 'amended'
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-amend-backup.hg (glob)
  $ hg status --change . -C
  A b.txt
  R a.txt

error conditions

  $ cat >> $HGRCPATH << EOF
  > [automv]
  > similarity=110
  > EOF
  $ hg commit -m 'revision to amend to'
  abort: automv.similarity must be between 0 and 100
  [255]