tests/test-import-eol.t

shelve: use matcher to restrict prefetch to just the modified files

Shelve currently operates by:
- make a temp commit
- identify all the bases necessary to shelve, put them in the bundle
- use exportfile to export the temp commit to the bundle ('file' here means
  "export to this fd", not "export this file")
- remove the temp commit

exportfile calls prefetchfiles, and prefetchfiles uses a matcher to restrict
what files it's going to prefetch; if it's not provided, it's alwaysmatcher.
This means that `hg shelve` in a remotefilelog repo can possibly download the
file contents of everything in the repository, even when it doesn't need to. It
luckily is restricted to the narrowspec (if there is one), but this is still a
lot of downloading that's just unnecessary, especially if there's a "smart"
VCS-aware filesystem involved.

exportfile is called with exactly one revision to emit, so we're just
restricting it to prefetching the files from that revision. The base revisions
having separate files should not be a concern since they're handled already;
example:

commit 10 is draft and modifies foo/a.txt and foo/b.txt
commit 11 is draft and modifies foo/a.txt
my working directory that I'm shelving modifies foo/b.txt

By the time we get to exportfile, commit 10 and 11 are already handled, so the
matcher only specifying foo/b.txt does not cause any problems. I verified this
by doing an `hg unbundle` on the bundle that shelve produces, and getting the
full contents of those commits back out, instead of just the files that were
modified in the shelve.

Differential Revision: https://phab.mercurial-scm.org/D5268

  $ cat > makepatch.py <<EOF
  > import sys
  > f = open(sys.argv[2], 'wb')
  > w = f.write
  > w(b'test message\n')
  > w(b'diff --git a/a b/a\n')
  > w(b'--- a/a\n')
  > w(b'+++ b/a\n')
  > w(b'@@ -1,5 +1,5 @@\n')
  > w(b' a\n')
  > w(b'-bbb\r\n')
  > w(b'+yyyy\r\n')
  > w(b' cc\r\n')
  > w({'empty:lf': b' \n',
  >    'empty:crlf': b' \r\n',
  >    'empty:stripped-lf': b'\n',
  >    'empty:stripped-crlf': b'\r\n'}[sys.argv[1]])
  > w(b' d\n')
  > w(b'-e\n')
  > w(b'\ No newline at end of file\n')
  > w(b'+z\r\n')
  > w(b'\ No newline at end of file\r\n')
  > EOF

  $ hg init repo
  $ cd repo
  $ echo '\.diff' > .hgignore


Test different --eol values

  $ "$PYTHON" -c 'open("a", "wb").write(b"a\nbbb\ncc\n\nd\ne")'
  $ hg ci -Am adda
  adding .hgignore
  adding a
  $ "$PYTHON" ../makepatch.py empty:lf eol.diff
  $ "$PYTHON" ../makepatch.py empty:crlf eol-empty-crlf.diff
  $ "$PYTHON" ../makepatch.py empty:stripped-lf eol-empty-stripped-lf.diff
  $ "$PYTHON" ../makepatch.py empty:stripped-crlf eol-empty-stripped-crlf.diff

invalid eol

  $ hg --config patch.eol='LFCR' import eol.diff
  applying eol.diff
  abort: unsupported line endings type: LFCR
  [255]
  $ hg revert -a


force LF

  $ hg --traceback --config patch.eol='LF' import eol.diff
  applying eol.diff
  $ hg id
  9e4ef7b3d4af tip
  $ cat a
  a
  yyyy
  cc
  
  d
  e (no-eol)
  $ hg st

 (test empty-line variants: all of them should generate the same revision)

  $ hg up -qC 0
  $ hg --config patch.eol='LF' import eol-empty-crlf.diff
  applying eol-empty-crlf.diff
  $ hg id
  9e4ef7b3d4af tip

  $ hg up -qC 0
  $ hg --config patch.eol='LF' import eol-empty-stripped-lf.diff
  applying eol-empty-stripped-lf.diff
  $ hg id
  9e4ef7b3d4af tip

  $ hg up -qC 0
  $ hg --config patch.eol='LF' import eol-empty-stripped-crlf.diff
  applying eol-empty-stripped-crlf.diff
  $ hg id
  9e4ef7b3d4af tip

force CRLF

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg --traceback --config patch.eol='CRLF' import eol.diff
  applying eol.diff
  $ cat a
  a\r (esc)
  yyyy\r (esc)
  cc\r (esc)
  \r (esc)
  d\r (esc)
  e (no-eol)
  $ hg st


auto EOL on LF file

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg --traceback --config patch.eol='auto' import eol.diff
  applying eol.diff
  $ cat a
  a
  yyyy
  cc
  
  d
  e (no-eol)
  $ hg st


auto EOL on CRLF file

  $ "$PYTHON" -c 'open("a", "wb").write(b"a\r\nbbb\r\ncc\r\n\r\nd\r\ne")'
  $ hg commit -m 'switch EOLs in a'
  $ hg --traceback --config patch.eol='auto' import eol.diff
  applying eol.diff
  $ cat a
  a\r (esc)
  yyyy\r (esc)
  cc\r (esc)
  \r (esc)
  d\r (esc)
  e (no-eol)
  $ hg st


auto EOL on new file or source without any EOL

  $ "$PYTHON" -c 'open("noeol", "wb").write(b"noeol")'
  $ hg add noeol
  $ hg commit -m 'add noeol'
  $ "$PYTHON" -c 'open("noeol", "wb").write(b"noeol\r\nnoeol\n")'
  $ "$PYTHON" -c 'open("neweol", "wb").write(b"neweol\nneweol\r\n")'
  $ hg add neweol
  $ hg diff --git > noeol.diff
  $ hg revert --no-backup noeol neweol
  $ rm neweol
  $ hg --traceback --config patch.eol='auto' import -m noeol noeol.diff
  applying noeol.diff
  $ cat noeol
  noeol\r (esc)
  noeol
  $ cat neweol
  neweol
  neweol\r (esc)
  $ hg st


Test --eol and binary patches

  $ "$PYTHON" -c 'open("b", "wb").write(b"a\x00\nb\r\nd")'
  $ hg ci -Am addb
  adding b
  $ "$PYTHON" -c 'open("b", "wb").write(b"a\x00\nc\r\nd")'
  $ hg diff --git > bin.diff
  $ hg revert --no-backup b

binary patch with --eol

  $ hg import --config patch.eol='CRLF' -m changeb bin.diff
  applying bin.diff
  $ cat b
  a\x00 (esc)
  c\r (esc)
  d (no-eol)
  $ hg st
  $ cd ..