view tests/test-commit-multiple.t @ 34857:84c6b9384d6a

log: add -L/--line-range option to follow file history by line range

We add an experimental -L/--line-range option to 'hg log' taking file patterns
along with a line range using the (new) FILE,FROMLINE-TOLINE syntax where FILE
may be a pattern (matching exactly one file). The resulting history is similar
to what the "followlines" revset except that, if --patch is specified,
only diff hunks within specified line range are shown.

Basically, this brings the CLI on par with what currently only exists in hgweb
through line selection in "file" and "annotate" views resulting in a file log
with filtered patch to only display followed line range.

The option may be specified multiple times and can be combined with --rev and
regular file patterns to further restrict revisions. Usage of this option
requires --follow; revisions are shown in descending order and renames are
followed. Only the --graph option is currently not supported.

The UI is the result of a consensus from review feedback at:

  https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-October/106749.html


The implementation spreads between commands.log() and cmdutil module.
In commands.log(), the main loop may now use a "hunksfilter" factory (similar
to "filematcher") that, for a given "rev", produces a filtering function
for diff hunks for a given file context object.
The logic to build revisions from -L/--line-range options lives in
cmdutil.getloglinerangerevs() which produces "revs", "filematcher" and
"hunksfilter" information. Revisions obtained by following files' line range
are filtered if they do not match the revset specified by --rev option. If
regular FILE arguments are passed along with -L options, both filematchers are
combined into a new matcher.

.. feature::

   Add an experimental -L/--line-range FILE,FROMLINE-TOLINE option to 'hg log'
   command to follow the history of files by line range. In combination with
   -p/--patch option, only diff hunks within specified line range will be
   displayed. Feedback, especially on UX aspects, is welcome.

# reproduce issue2264, issue2516

create test repo
  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > transplant =
  > EOF
  $ hg init repo
  $ cd repo
  $ template="{rev}  {desc|firstline}  [{branch}]\n"

# we need to start out with two changesets on the default branch
# in order to avoid the cute little optimization where transplant
# pulls rather than transplants
add initial changesets
  $ echo feature1 > file1
  $ hg ci -Am"feature 1"
  adding file1
  $ echo feature2 >> file2
  $ hg ci -Am"feature 2"
  adding file2

# The changes to 'bugfix' are enough to show the bug: in fact, with only
# those changes, it's a very noisy crash ("RuntimeError: nothing
# committed after transplant").  But if we modify a second file in the
# transplanted changesets, the bug is much more subtle: transplant
# silently drops the second change to 'bugfix' on the floor, and we only
# see it when we run 'hg status' after transplanting.  Subtle data loss
# bugs are worse than crashes, so reproduce the subtle case here.
commit bug fixes on bug fix branch
  $ hg branch fixes
  marked working directory as branch fixes
  (branches are permanent and global, did you want a bookmark?)
  $ echo fix1 > bugfix
  $ echo fix1 >> file1
  $ hg ci -Am"fix 1"
  adding bugfix
  $ echo fix2 > bugfix
  $ echo fix2 >> file1
  $ hg ci -Am"fix 2"
  $ hg log -G --template="$template"
  @  3  fix 2  [fixes]
  |
  o  2  fix 1  [fixes]
  |
  o  1  feature 2  [default]
  |
  o  0  feature 1  [default]
  
transplant bug fixes onto release branch
  $ hg update 0
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg branch release
  marked working directory as branch release
  $ hg transplant 2 3
  applying [0-9a-f]{12} (re)
  [0-9a-f]{12} transplanted to [0-9a-f]{12} (re)
  applying [0-9a-f]{12} (re)
  [0-9a-f]{12} transplanted to [0-9a-f]{12} (re)
  $ hg log -G --template="$template"
  @  5  fix 2  [release]
  |
  o  4  fix 1  [release]
  |
  | o  3  fix 2  [fixes]
  | |
  | o  2  fix 1  [fixes]
  | |
  | o  1  feature 2  [default]
  |/
  o  0  feature 1  [default]
  
  $ hg status
  $ hg status --rev 0:4
  M file1
  A bugfix
  $ hg status --rev 4:5
  M bugfix
  M file1

now test that we fixed the bug for all scripts/extensions
  $ cat > $TESTTMP/committwice.py <<__EOF__
  > from mercurial import ui, hg, match, node
  > from time import sleep
  > 
  > def replacebyte(fn, b):
  >     f = open(fn, "rb+")
  >     f.seek(0, 0)
  >     f.write(b)
  >     f.close()
  > 
  > def printfiles(repo, rev):
  >     print("revision %s files: %s" % (rev, repo[rev].files()))
  > 
  > repo = hg.repository(ui.ui.load(), '.')
  > assert len(repo) == 6, \
  >        "initial: len(repo): %d, expected: 6" % len(repo)
  > 
  > replacebyte("bugfix", "u")
  > sleep(2)
  > try:
  >     print("PRE: len(repo): %d" % len(repo))
  >     wlock = repo.wlock()
  >     lock = repo.lock()
  >     replacebyte("file1", "x")
  >     repo.commit(text="x", user="test", date=(0, 0))
  >     replacebyte("file1", "y")
  >     repo.commit(text="y", user="test", date=(0, 0))
  >     print("POST: len(repo): %d" % len(repo))
  > finally:
  >     lock.release()
  >     wlock.release()
  > printfiles(repo, 6)
  > printfiles(repo, 7)
  > __EOF__
  $ $PYTHON $TESTTMP/committwice.py
  PRE: len(repo): 6
  POST: len(repo): 8
  revision 6 files: ['bugfix', 'file1']
  revision 7 files: ['file1']

Do a size-preserving modification outside of that process
  $ echo abcd > bugfix
  $ hg status
  M bugfix
  $ hg log --template "{rev}  {desc}  {files}\n" -r5:
  5  fix 2  bugfix file1
  6  x  bugfix file1
  7  y  file1

  $ cd ..