Added git hyper-blame, a tool that skips unwanted commits in git blame.

Currently, the script requires you to pass the unwanted commits on the
command line, but eventually, you could configure it with a file
(checked into the repo) that provides a fixed set of commits to always
skip (such as commits that do a huge amount of renaming and nothing
else).

BUG=574290

Review URL: https://codereview.chromium.org/1559943003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@298544 0039d316-1c4b-4281-b951-d872f2087c98

git-hyper-blame

+#!/usr/bin/env bash
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+. $(type -P python_runner.sh)

git_common.py

@@ -281,6 +281,16 @@ def once(function):
 ## Git functions
 
 
+def blame(filename, revision=None, porcelain=False, *args):
+  command = ['blame']
+  if porcelain:
+    command.append('-p')
+  if revision is not None:
+    command.append(revision)
+  command.extend(['--', filename])
+  return run(*command)
+
+
 def branch_config(branch, option, default=None):
   return config('branch.%s.%s' % (branch, option), default=default)
 
@@ -546,10 +556,39 @@ def remove_merge_base(branch):
   del_branch_config(branch, 'base-upstream')
 
 
+def repo_root():
+  """Returns the absolute path to the repository root."""
+  return run('rev-parse', '--show-toplevel')
+
+
 def root():
   return config('depot-tools.upstream', 'origin/master')
 
 
+@contextlib.contextmanager
+def less():  # pragma: no cover
+  """Runs 'less' as context manager yielding its stdin as a PIPE.
+
+  Automatically checks if sys.stdout is a non-TTY stream. If so, it avoids
+  running less and just yields sys.stdout.
+  """
+  if not sys.stdout.isatty():
+    yield sys.stdout
+    return
+
+  # Run with the same options that git uses (see setup_pager in git repo).
+  # -F: Automatically quit if the output is less than one screen.
+  # -R: Don't escape ANSI color codes.
+  # -X: Don't clear the screen before starting.
+  cmd = ('less', '-FRX')
+  try:
+    proc = subprocess2.Popen(cmd, stdin=subprocess2.PIPE)
+    yield proc.stdin
+  finally:
+    proc.stdin.close()
+    proc.wait()
+
+
 def run(*cmd, **kwargs):
   """The same as run_with_stderr, except it only returns stdout."""
   return run_with_stderr(*cmd, **kwargs)[0]

git_dates.py

+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Utility module for dealing with Git timestamps."""
+
+import datetime
+
+
+def timestamp_offset_to_datetime(timestamp, offset):
+  """Converts a timestamp + offset into a datetime.datetime.
+
+  Useful for dealing with the output of porcelain commands, which provide times
+  as timestamp and offset strings.
+
+  Args:
+    timestamp: An int UTC timestamp, or a string containing decimal digits.
+    offset: A str timezone offset. e.g., '-0800'.
+
+  Returns:
+    A tz-aware datetime.datetime for this timestamp.
+  """
+  timestamp = int(timestamp)
+  tz = FixedOffsetTZ.from_offset_string(offset)
+  return datetime.datetime.fromtimestamp(timestamp, tz)
+
+
+def datetime_string(dt):
+  """Converts a tz-aware datetime.datetime into a string in git format."""
+  return dt.strftime('%Y-%m-%d %H:%M:%S %z')
+
+
+# Adapted from: https://docs.python.org/2/library/datetime.html#tzinfo-objects
+class FixedOffsetTZ(datetime.tzinfo):
+  def __init__(self, offset, name):
+    datetime.tzinfo.__init__(self)
+    self.__offset = offset
+    self.__name = name
+
+  def __repr__(self):  # pragma: no cover
+    return '{}({!r}, {!r})'.format(type(self).__name__, self.__offset,
+                                   self.__name)
+
+  @classmethod
+  def from_offset_string(cls, offset):
+    try:
+      hours = int(offset[:-2])
+      minutes = int(offset[-2:])
+    except ValueError:
+      return cls(datetime.timedelta(0), 'UTC')
+
+    delta = datetime.timedelta(hours=hours, minutes=minutes)
+    return cls(delta, offset)
+
+  def utcoffset(self, dt):
+    return self.__offset
+
+  def tzname(self, dt):
+    return self.__name
+
+  def dst(self, dt):
+    return datetime.timedelta(0)

git_hyper_blame.py

+#!/usr/bin/env python
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Wrapper around git blame that ignores certain commits.
+"""
+
+from __future__ import print_function
+
+import argparse
+import collections
+import logging
+import os
+import subprocess2
+import sys
+
+import git_common
+import git_dates
+
+
+logging.getLogger().setLevel(logging.INFO)
+
+
+class Commit(object):
+  """Info about a commit."""
+  def __init__(self, commithash):
+    self.commithash = commithash
+    self.author = None
+    self.author_mail = None
+    self.author_time = None
+    self.author_tz = None
+    self.committer = None
+    self.committer_mail = None
+    self.committer_time = None
+    self.committer_tz = None
+    self.summary = None
+    self.boundary = None
+    self.previous = None
+    self.filename = None
+
+  def __repr__(self):  # pragma: no cover
+    return '<Commit %s>' % self.commithash
+
+
+BlameLine = collections.namedtuple(
+    'BlameLine',
+    'commit context lineno_then lineno_now modified')
+
+
+def parse_blame(blameoutput):
+  """Parses the output of git blame -p into a data structure."""
+  lines = blameoutput.split('\n')
+  i = 0
+  commits = {}
+
+  while i < len(lines):
+    # Read a commit line and parse it.
+    line = lines[i]
+    i += 1
+    if not line.strip():
+      continue
+    commitline = line.split()
+    commithash = commitline[0]
+    lineno_then = int(commitline[1])
+    lineno_now = int(commitline[2])
+
+    try:
+      commit = commits[commithash]
+    except KeyError:
+      commit = Commit(commithash)
+      commits[commithash] = commit
+
+    # Read commit details until we find a context line.
+    while i < len(lines):
+      line = lines[i]
+      i += 1
+      if line.startswith('\t'):
+        break
+
+      try:
+        key, value = line.split(' ', 1)
+      except ValueError:
+        key = line
+        value = True
+      setattr(commit, key.replace('-', '_'), value)
+
+    context = line[1:]
+
+    yield BlameLine(commit, context, lineno_then, lineno_now, False)
+
+
+def print_table(table, colsep=' ', rowsep='\n', align=None, out=sys.stdout):
+  """Print a 2D rectangular array, aligning columns with spaces.
+
+  Args:
+    align: Optional string of 'l' and 'r', designating whether each column is
+           left- or right-aligned. Defaults to left aligned.
+  """
+  if len(table) == 0:
+    return
+
+  colwidths = None
+  for row in table:
+    if colwidths is None:
+      colwidths = [len(x) for x in row]
+    else:
+      colwidths = [max(colwidths[i], len(x)) for i, x in enumerate(row)]
+
+  if align is None:  # pragma: no cover
+    align = 'l' * len(colwidths)
+
+  for row in table:
+    cells = []
+    for i, cell in enumerate(row):
+      padding = ' ' * (colwidths[i] - len(cell))
+      if align[i] == 'r':
+        cell = padding + cell
+      elif i < len(row) - 1:
+        # Do not pad the final column if left-aligned.
+        cell += padding
+      cells.append(cell)
+    try:
+      print(*cells, sep=colsep, end=rowsep, file=out)
+    except IOError:  # pragma: no cover
+      # Can happen on Windows if the pipe is closed early.
+      pass
+
+
+def pretty_print(parsedblame, show_filenames=False, out=sys.stdout):
+  """Pretty-prints the output of parse_blame."""
+  table = []
+  for line in parsedblame:
+    author_time = git_dates.timestamp_offset_to_datetime(
+        line.commit.author_time, line.commit.author_tz)
+    row = [line.commit.commithash[:8],
+           '(' + line.commit.author,
+           git_dates.datetime_string(author_time),
+           str(line.lineno_now) + ('*' if line.modified else '') + ')',
+           line.context]
+    if show_filenames:
+      row.insert(1, line.commit.filename)
+    table.append(row)
+  print_table(table, align='llllrl' if show_filenames else 'lllrl', out=out)
+
+
+def get_parsed_blame(filename, revision='HEAD'):
+  blame = git_common.blame(filename, revision=revision, porcelain=True)
+  return list(parse_blame(blame))
+
+
+def hyper_blame(ignored, filename, revision='HEAD', out=sys.stdout,
+                err=sys.stderr):
+  # Map from commit to parsed blame from that commit.
+  blame_from = {}
+
+  def cache_blame_from(filename, commithash):
+    try:
+      return blame_from[commithash]
+    except KeyError:
+      parsed = get_parsed_blame(filename, commithash)
+      blame_from[commithash] = parsed
+      return parsed
+
+  try:
+    parsed = cache_blame_from(filename, git_common.hash_one(revision))
+  except subprocess2.CalledProcessError as e:
+    err.write(e.stderr)
+    return e.returncode
+
+  new_parsed = []
+
+  # We don't show filenames in blame output unless we have to.
+  show_filenames = False
+
+  for line in parsed:
+    # If a line references an ignored commit, blame that commit's parent
+    # repeatedly until we find a non-ignored commit.
+    while line.commit.commithash in ignored:
+      if line.commit.previous is None:
+        # You can't ignore the commit that added this file.
+        break
+
+      previouscommit, previousfilename = line.commit.previous.split(' ', 1)
+      parent_blame = cache_blame_from(previousfilename, previouscommit)
+
+      if len(parent_blame) == 0:
+        # The previous version of this file was empty, therefore, you can't
+        # ignore this commit.
+        break
+
+      # line.lineno_then is the line number in question at line.commit.
+      # TODO(mgiuca): This will be incorrect if line.commit added or removed
+      # lines. Translate that line number so that it refers to the position of
+      # the same line on previouscommit.
+      lineno_previous = line.lineno_then
+      logging.debug('ignore commit %s on line p%d/t%d/n%d',
+                    line.commit.commithash, lineno_previous, line.lineno_then,
+                    line.lineno_now)
+
+      # Get the line at lineno_previous in the parent commit.
+      assert lineno_previous > 0
+      try:
+        newline = parent_blame[lineno_previous - 1]
+      except IndexError:
+        # lineno_previous is a guess, so it may be past the end of the file.
+        # Just grab the last line in the file.
+        newline = parent_blame[-1]
+
+      # Replace the commit and lineno_then, but not the lineno_now or context.
+      logging.debug('    replacing with %r', newline)
+      line = BlameLine(newline.commit, line.context, lineno_previous,
+                       line.lineno_now, True)
+
+    # If any line has a different filename to the file's current name, turn on
+    # filename display for the entire blame output.
+    if line.commit.filename != filename:
+      show_filenames = True
+
+    new_parsed.append(line)
+
+  pretty_print(new_parsed, show_filenames=show_filenames, out=out)
+
+  return 0
+
+def main(args, stdout=sys.stdout, stderr=sys.stderr):
+  parser = argparse.ArgumentParser(
+      prog='git hyper-blame',
+      description='git blame with support for ignoring certain commits.')
+  parser.add_argument('-i', metavar='REVISION', action='append', dest='ignored',
+                      default=[], help='a revision to ignore')
+  parser.add_argument('revision', nargs='?', default='HEAD', metavar='REVISION',
+                      help='revision to look at')
+  parser.add_argument('filename', metavar='FILE', help='filename to blame')
+
+  args = parser.parse_args(args)
+  try:
+    repo_root = git_common.repo_root()
+  except subprocess2.CalledProcessError as e:
+    stderr.write(e.stderr)
+    return e.returncode
+
+  # Make filename relative to the repository root, and cd to the root dir (so
+  # all filenames throughout this script are relative to the root).
+  filename = os.path.relpath(args.filename, repo_root)
+  os.chdir(repo_root)
+
+  # Normalize filename so we can compare it to other filenames git gives us.
+  filename = os.path.normpath(filename)
+  filename = os.path.normcase(filename)
+
+  ignored = set()
+  for c in args.ignored:
+    try:
+      ignored.add(git_common.hash_one(c))
+    except subprocess2.CalledProcessError as e:
+      # Custom error message (the message from git-rev-parse is inappropriate).
+      stderr.write('fatal: unknown revision \'%s\'.\n' % c)
+      return e.returncode
+
+  return hyper_blame(ignored, filename, args.revision, out=stdout, err=stderr)
+
+
+if __name__ == '__main__':  # pragma: no cover
+  with git_common.less() as less_input:
+    sys.exit(main(sys.argv[1:], stdout=less_input))

man/html/depot_tools.html

@@ -804,6 +804,14 @@ Freeze all changes on a branch (indexed and unindexed).
 </p>
 </dd>
 <dt class="hdlist1">
+<a href="git-hyper-blame.html">git-hyper-blame(1)</a>
+</dt>
+<dd>
+<p>
+Like git blame, but with the ability to ignore or bypass certain commits.
+</p>
+</dd>
+<dt class="hdlist1">
 <a href="git-map-branches.html">git-map-branches(1)</a>
 </dt>
 <dd>
@@ -919,7 +927,7 @@ Print a diff of the current branch, compared to its upstream.
 <div id="footnotes"><hr /></div>
 <div id="footer">
 <div id="footer-text">
-Last updated 2014-09-09 14:15:07 PDT
+Last updated 2016-01-28 16:40:21 AEDT
 </div>
 </div>
 </body>

man/man1/git-hyper-blame.1

+'\" t
+.\"     Title: git-hyper-blame
+.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
+.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
+.\"      Date: 01/28/2016
+.\"    Manual: Chromium depot_tools Manual
+.\"    Source: depot_tools 7143379
+.\"  Language: English
+.\"
+.TH "GIT\-HYPER\-BLAME" "1" "01/28/2016" "depot_tools 7143379" "Chromium depot_tools Manual"
+.\" -----------------------------------------------------------------
+.\" * Define some portability stuff
+.\" -----------------------------------------------------------------
+.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+.\" http://bugs.debian.org/507673
+.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
+.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+.ie \n(.g .ds Aq \(aq
+.el       .ds Aq '
+.\" -----------------------------------------------------------------
+.\" * set default formatting
+.\" -----------------------------------------------------------------
+.\" disable hyphenation
+.nh
+.\" disable justification (adjust text to left margin only)
+.ad l
+.\" -----------------------------------------------------------------
+.\" * MAIN CONTENT STARTS HERE *
+.\" -----------------------------------------------------------------
+.SH "NAME"
+git-hyper-blame \- Like git blame, but with the ability to ignore or bypass certain commits\&.
+.SH "SYNOPSIS"
+.sp
+.nf
+\fIgit hyper\-blame\fR [\-i <rev> [\-i <rev> \&...]] [<rev>] [\-\-] <file>
+.fi
+.sp
+.SH "DESCRIPTION"
+.sp
+git hyper\-blame is like git blame but it can ignore or "look through" a given set of commits, to find the real culprit\&.
+.sp
+This is useful if you have a commit that makes sweeping changes that are unlikely to be what you are looking for in a blame, such as mass reformatting or renaming\&. By adding these commits to the hyper\-blame ignore list, git hyper\-blame will look past these commits to find the previous commit that touched a given line\&.
+.sp
+Follows the normal blame syntax: annotates <file> with the revision that last modified each line\&. Optional <rev> specifies the revision of <file> to start from\&.
+.SH "OPTIONS"
+.PP
+\-i <rev>
+.RS 4
+A revision to ignore\&. Can be specified as many times as needed\&.
+.RE
+.SH "EXAMPLE"
+.sp
+Let\(cqs run git blame on a file:
+.sp
+
+.sp
+.if n \{\
+.RS 4
+.\}
+.nf
+\fB$ git blame ipsum\&.txt\fR
+c6eb3bfa (lorem           2014\-08\-11 23:15:57 +0000 1) LOREM IPSUM DOLOR SIT AMET, CONSECTETUR
+3ddda43c (auto\-uppercaser 2014\-07\-05 02:05:18 +0000 2) ADIPISCING ELIT, SED DO EIUSMOD TEMPOR
+3ddda43c (auto\-uppercaser 2014\-07\-05 02:05:18 +0000 3) INCIDIDUNT UT LABORE ET DOLORE MAGNA
+3ddda43c (auto\-uppercaser 2014\-07\-05 02:05:18 +0000 4) ALIQUA\&. UT ENIM AD MINIM VENIAM, QUIS
+c6eb3bfa (lorem           2014\-08\-11 23:15:57 +0000 5) NOSTRUD EXERCITATION ULLAMCO LABORIS
+3ddda43c (auto\-uppercaser 2014\-07\-05 02:05:18 +0000 6) NISI UT ALIQUIP EX EA COMMODO CONSEQUAT\&.
+.fi
+.if n \{\
+.RE
+.\}
+.sp
+.sp
+Notice that almost the entire file has been blamed on a formatting change? You aren\(cqt interested in the uppercasing of the file\&. You want to know who wrote/modified those lines in the first place\&. Just tell hyper\-blame to ignore that commit:
+.sp
+
+.sp
+.if n \{\
+.RS 4
+.\}
+.nf
+\fB$ git hyper\-blame \-i 3ddda43c ipsum\&.txt\fR
+c6eb3bfa (lorem 2014\-08\-11 23:15:57 +0000  1) LOREM IPSUM DOLOR SIT AMET, CONSECTETUR
+134200d1 (lorem 2014\-04\-10 08:54:46 +0000 2*) ADIPISCING ELIT, SED DO EIUSMOD TEMPOR
+a34a1d0d (ipsum 2014\-04\-11 11:25:04 +0000 3*) INCIDIDUNT UT LABORE ET DOLORE MAGNA
+134200d1 (lorem 2014\-04\-10 08:54:46 +0000 4*) ALIQUA\&. UT ENIM AD MINIM VENIAM, QUIS
+c6eb3bfa (lorem 2014\-08\-11 23:15:57 +0000  5) NOSTRUD EXERCITATION ULLAMCO LABORIS
+0f0d17bd (dolor 2014\-06\-02 11:31:48 +0000 6*) NISI UT ALIQUIP EX EA COMMODO CONSEQUAT\&.
+.fi
+.if n \{\
+.RE
+.\}
+.sp
+.sp
+hyper\-blame places a * next to any line where it has skipped over an ignored commit, so you know that the line in question has been changed (by an ignored commit) since the given person wrote it\&.
+.SH "BUGS"
+.sp
+.RS 4
+.ie n \{\
+\h'-04'\(bu\h'+03'\c
+.\}
+.el \{\
+.sp -1
+.IP \(bu 2.3
+.\}
+When a commit is ignored, hyper\-blame currently just blames the same line in the previous version of the file\&. This can be wildly inaccurate if the ignored commit adds or removes lines, resulting in a completely wrong commit being blamed\&.
+.RE
+.sp
+.RS 4
+.ie n \{\
+\h'-04'\(bu\h'+03'\c
+.\}
+.el \{\
+.sp -1
+.IP \(bu 2.3
+.\}
+There is currently no way to pass the ignore list as a file\&.
+.RE
+.sp
+.RS 4
+.ie n \{\
+\h'-04'\(bu\h'+03'\c
+.\}
+.el \{\
+.sp -1
+.IP \(bu 2.3
+.\}
+It should be possible for a git repository to configure an automatic list of commits to ignore (like
+\&.gitignore), so that project owners can maintain a list of "big change" commits that are ignored by hyper\-blame by default\&.
+.RE
+.SH "SEE ALSO"
+.sp
+\fBgit-blame\fR(1)
+.SH "CHROMIUM DEPOT_TOOLS"
+.sp
+Part of the chromium \fBdepot_tools\fR(7) suite\&. These tools are meant to assist with the development of chromium and related projects\&. Download the tools from \m[blue]\fBhere\fR\m[]\&\s-2\u[1]\d\s+2\&.
+.SH "NOTES"
+.IP " 1." 4
+here
+.RS 4
+\%https://chromium.googlesource.com/chromium/tools/depot_tools.git
+.RE

man/man7/depot_tools.7

 '\" t
 .\"     Title: depot_tools
 .\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
-.\" Generator: DocBook XSL Stylesheets v1.76.1 <http://docbook.sf.net/>
-.\"      Date: 09/09/2014
+.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
+.\"      Date: 01/28/2016
 .\"    Manual: Chromium depot_tools Manual
-.\"    Source: depot_tools 40ce153
+.\"    Source: depot_tools 7143379
 .\"  Language: English
 .\"
-.TH "DEPOT_TOOLS" "7" "09/09/2014" "depot_tools 40ce153" "Chromium depot_tools Manual"
+.TH "DEPOT_TOOLS" "7" "01/28/2016" "depot_tools 7143379" "Chromium depot_tools Manual"
 .\" -----------------------------------------------------------------
 .\" * Define some portability stuff
 .\" -----------------------------------------------------------------
@@ -62,6 +62,11 @@ Extract meta\-information expressed as footers in a commit message\&.
 Freeze all changes on a branch (indexed and unindexed)\&.
 .RE
 .PP
+\fBgit-hyper-blame\fR(1)
+.RS 4
+Like git blame, but with the ability to ignore or bypass certain commits\&.
+.RE
+.PP
 \fBgit-map-branches\fR(1)
 .RS 4
 Helper script to display all local git branches with \(oqupstream\(cq hierarchy in colorized terminal format\&.

man/src/_git-hyper-blame_desc.helper.txt

+Like git blame, but with the ability to ignore or bypass certain commits.

man/src/git-hyper-blame.demo.1.sh

+#!/usr/bin/env bash
+. git-hyper-blame.demo.common.sh
+run git blame ipsum.txt

man/src/git-hyper-blame.demo.2.sh

+#!/usr/bin/env bash
+. git-hyper-blame.demo.common.sh
+IGNORE=$(git rev-parse HEAD^)
+run git hyper-blame -i ${IGNORE:0:8} ipsum.txt

man/src/git-hyper-blame.demo.common.sh

+#!/usr/bin/env bash
+. demo_repo.sh
+
+# Construct a plausible file history.
+set_user "lorem"
+V1="Lorem ipsum dolor sit amet, consectetur*
+adipiscing elit, sed do eiusmod tempor
+incididunt ut labore et dolore magna*
+aliqua. Ut enim ad minim veniam, quis
+nostrud exercitation ullamco laboris**
+nisi ut aliquip ex ea commodo consequat.*"
+add "ipsum.txt" "$V1"
+c "Added Lorem Ipsum"
+tick 95408
+
+set_user "ipsum"
+V2="Lorem ipsum dolor sit amet, consectetur*
+adipiscing elit, sed do eiusmod tempor
+incididunt ut labore et dolore magna
+aliqua. Ut enim ad minim veniam, quis
+nostrud exercitation ullamco laboris**
+nisi ut aliquip ex ea commodo consequat.*"
+add "ipsum.txt" "$V2"
+c "Change 1"
+tick 4493194
+
+set_user "dolor"
+V3="Lorem ipsum dolor sit amet, consectetur*
+adipiscing elit, sed do eiusmod tempor
+incididunt ut labore et dolore magna
+aliqua. Ut enim ad minim veniam, quis
+nostrud exercitation ullamco laboris*
+nisi ut aliquip ex ea commodo consequat."
+add "ipsum.txt" "$V3"
+c "Change 2"
+tick 2817200
+
+set_user "auto-uppercaser"
+V4="LOREM IPSUM DOLOR SIT AMET, CONSECTETUR*
+ADIPISCING ELIT, SED DO EIUSMOD TEMPOR
+INCIDIDUNT UT LABORE ET DOLORE MAGNA
+ALIQUA. UT ENIM AD MINIM VENIAM, QUIS
+NOSTRUD EXERCITATION ULLAMCO LABORIS*
+NISI UT ALIQUIP EX EA COMMODO CONSEQUAT."
+add "ipsum.txt" "$V4"
+c "Automatic upper-casing of all text."
+tick 3273029
+
+set_user "lorem"
+V4="LOREM IPSUM DOLOR SIT AMET, CONSECTETUR
+ADIPISCING ELIT, SED DO EIUSMOD TEMPOR
+INCIDIDUNT UT LABORE ET DOLORE MAGNA
+ALIQUA. UT ENIM AD MINIM VENIAM, QUIS
+NOSTRUD EXERCITATION ULLAMCO LABORIS
+NISI UT ALIQUIP EX EA COMMODO CONSEQUAT."
+add "ipsum.txt" "$V4"
+c "Change 3."

man/src/git-hyper-blame.txt

+git-hyper-blame(1)
+==================
+
+NAME
+----
+git-hyper-blame -
+include::_git-hyper-blame_desc.helper.txt[]
+
+SYNOPSIS
+--------
+[verse]
+'git hyper-blame' [-i <rev> [-i <rev> ...]] [<rev>] [--] <file>
+
+DESCRIPTION
+-----------
+
+`git hyper-blame` is like `git blame` but it can ignore or "look through" a
+given set of commits, to find the real culprit.
+
+This is useful if you have a commit that makes sweeping changes that are
+unlikely to be what you are looking for in a blame, such as mass reformatting or
+renaming. By adding these commits to the hyper-blame ignore list, `git
+hyper-blame` will look past these commits to find the previous commit that
+touched a given line.
+
+Follows the normal `blame` syntax: annotates `<file>` with the revision that
+last modified each line. Optional `<rev>` specifies the revision of `<file>` to
+start from.
+
+OPTIONS
+-------
+
+-i <rev>::
+  A revision to ignore. Can be specified as many times as needed.
+
+EXAMPLE
+-------
+
+Let's run `git blame` on a file:
+
+demo:1[]
+
+Notice that almost the entire file has been blamed on a formatting change? You
+aren't interested in the uppercasing of the file. You want to know who
+wrote/modified those lines in the first place. Just tell `hyper-blame` to ignore
+that commit:
+
+demo:2[]
+
+`hyper-blame` places a `*` next to any line where it has skipped over an ignored
+commit, so you know that the line in question has been changed (by an ignored
+commit) since the given person wrote it.
+
+BUGS
+----
+
+- When a commit is ignored, hyper-blame currently just blames the same line in
+  the previous version of the file. This can be wildly inaccurate if the ignored
+  commit adds or removes lines, resulting in a completely wrong commit being
+  blamed.
+- There is currently no way to pass the ignore list as a file.
+- It should be possible for a git repository to configure an automatic list of
+  commits to ignore (like `.gitignore`), so that project owners can maintain a
+  list of "big change" commits that are ignored by hyper-blame by default.
+
+SEE ALSO
+--------
+linkgit:git-blame[1]
+
+include::_footer.txt[]
+
+// vim: ft=asciidoc:

tests/git_common_test.py

@@ -176,15 +176,15 @@ class GitReadOnlyFunctionsTest(git_test_utils.GitRepoReadOnlyTestBase,
   COMMIT_C = {
     'some/files/file2': {
       'mode': 0755,
-      'data': 'file2 - vanilla'},
+      'data': 'file2 - vanilla\n'},
   }
 
   COMMIT_E = {
-    'some/files/file2': {'data': 'file2 - merged'},
+    'some/files/file2': {'data': 'file2 - merged\n'},
   }
 
   COMMIT_D = {
-    'some/files/file2': {'data': 'file2 - vanilla\nfile2 - merged'},
+    'some/files/file2': {'data': 'file2 - vanilla\nfile2 - merged\n'},
   }
 
   def testHashes(self):
@@ -259,6 +259,40 @@ class GitReadOnlyFunctionsTest(git_test_utils.GitRepoReadOnlyTestBase,
     self.repo.git('config', 'branch.master.dormant', 'true')
     self.assertTrue(self.repo.run(self.gc.is_dormant, 'master'))
 
+  def testBlame(self):
+    def get_porcelain_for_commit(commit_name, lines):
+      format_string = ('%H {}\nauthor %an\nauthor-mail <%ae>\nauthor-time %at\n'
+                       'author-tz +0000\ncommitter %cn\ncommitter-mail <%ce>\n'
+                       'committer-time %ct\ncommitter-tz +0000\nsummary {}')
+      format_string = format_string.format(lines, commit_name)
+      info = self.repo.show_commit(commit_name, format_string=format_string)
+      return info.split('\n')
+
+    # Expect to blame line 1 on C, line 2 on E.
+    c_short = self.repo['C'][:8]
+    c_author = self.repo.show_commit('C', format_string='%an %ai')
+    e_short = self.repo['E'][:8]
+    e_author = self.repo.show_commit('E', format_string='%an %ai')
+    expected_output = ['%s (%s 1) file2 - vanilla' % (c_short, c_author),
+                       '%s (%s 2) file2 - merged' % (e_short, e_author)]
+    self.assertEqual(expected_output,
+                     self.repo.run(self.gc.blame, 'some/files/file2',
+                                   'tag_D').split('\n'))
+
+    # Test porcelain.
+    expected_output = []
+    expected_output.extend(get_porcelain_for_commit('C', '1 1 1'))
+    expected_output.append('previous %s some/files/file2' % self.repo['B'])
+    expected_output.append('filename some/files/file2')
+    expected_output.append('\tfile2 - vanilla')
+    expected_output.extend(get_porcelain_for_commit('E', '1 2 1'))
+    expected_output.append('previous %s some/files/file2' % self.repo['B'])
+    expected_output.append('filename some/files/file2')
+    expected_output.append('\tfile2 - merged')
+    self.assertEqual(expected_output,
+                     self.repo.run(self.gc.blame, 'some/files/file2',
+                                   'tag_D', porcelain=True).split('\n'))
+
   def testParseCommitrefs(self):
     ret = self.repo.run(
       self.gc.parse_commitrefs, *[
@@ -280,6 +314,17 @@ class GitReadOnlyFunctionsTest(git_test_utils.GitRepoReadOnlyTestBase,
     with self.assertRaisesRegexp(Exception, r"one of \('master', 'bananas'\)"):
       self.repo.run(self.gc.parse_commitrefs, 'master', 'bananas')
 
+  def testRepoRoot(self):
+    def cd_and_repo_root(path):
+      print(os.getcwd())
+      os.chdir(path)
+      return self.gc.repo_root()
+
+    self.assertEqual(self.repo.repo_path, self.repo.run(self.gc.repo_root))
+    # cd to a subdirectory; repo_root should still return the root dir.
+    self.assertEqual(self.repo.repo_path,
+                     self.repo.run(cd_and_repo_root, 'some/files'))
+
   def testTags(self):
     self.assertEqual(set(self.repo.run(self.gc.tags)),
                      {'tag_'+l for l in 'ABCDE'})

tests/git_dates_test.py

+#!/usr/bin/env python
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+"""Tests for git_dates."""
+
+import datetime
+import os
+import sys
+import unittest
+
+DEPOT_TOOLS_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, DEPOT_TOOLS_ROOT)
+
+from testing_support import coverage_utils
+
+
+class GitDatesTestBase(unittest.TestCase):
+  @classmethod
+  def setUpClass(cls):
+    super(GitDatesTestBase, cls).setUpClass()
+    import git_dates
+    cls.git_dates = git_dates
+
+
+class GitDatesTest(GitDatesTestBase):
+  def testTimestampOffsetToDatetime(self):
+    # 2016-01-25 06:25:43 UTC
+    timestamp = 1453703143
+
+    offset = '+1100'
+    expected_tz = self.git_dates.FixedOffsetTZ(datetime.timedelta(hours=11), '')
+    expected = datetime.datetime(2016, 1, 25, 17, 25, 43, tzinfo=expected_tz)
+    result = self.git_dates.timestamp_offset_to_datetime(timestamp, offset)
+    self.assertEquals(expected, result)
+    self.assertEquals(datetime.timedelta(hours=11), result.utcoffset())
+    self.assertEquals('+1100', result.tzname())
+    self.assertEquals(datetime.timedelta(0), result.dst())
+
+    offset = '-0800'
+    expected_tz = self.git_dates.FixedOffsetTZ(datetime.timedelta(hours=-8), '')
+    expected = datetime.datetime(2016, 1, 24, 22, 25, 43, tzinfo=expected_tz)
+    result = self.git_dates.timestamp_offset_to_datetime(timestamp, offset)
+    self.assertEquals(expected, result)
+    self.assertEquals(datetime.timedelta(hours=-8), result.utcoffset())
+    self.assertEquals('-0800', result.tzname())
+    self.assertEquals(datetime.timedelta(0), result.dst())
+
+    # Invalid offset.
+    offset = '-08xx'
+    expected_tz = self.git_dates.FixedOffsetTZ(datetime.timedelta(hours=0), '')
+    expected = datetime.datetime(2016, 1, 25, 6, 25, 43, tzinfo=expected_tz)
+    result = self.git_dates.timestamp_offset_to_datetime(timestamp, offset)
+    self.assertEquals(expected, result)
+    self.assertEquals(datetime.timedelta(hours=0), result.utcoffset())
+    self.assertEquals('UTC', result.tzname())
+    self.assertEquals(datetime.timedelta(0), result.dst())
+
+    # Offset out of range.
+    offset = '+2400'
+    self.assertRaises(ValueError, self.git_dates.timestamp_offset_to_datetime,
+                      timestamp, offset)
+
+  def testDatetimeString(self):
+    tz = self.git_dates.FixedOffsetTZ(datetime.timedelta(hours=11), '')
+    dt = datetime.datetime(2016, 1, 25, 17, 25, 43, tzinfo=tz)
+    self.assertEquals('2016-01-25 17:25:43 +1100',
+                      self.git_dates.datetime_string(dt))
+
+    tz = self.git_dates.FixedOffsetTZ(datetime.timedelta(hours=-8), '')
+    dt = datetime.datetime(2016, 1, 24, 22, 25, 43, tzinfo=tz)
+    self.assertEquals('2016-01-24 22:25:43 -0800',
+                      self.git_dates.datetime_string(dt))
+
+
+if __name__ == '__main__':
+  sys.exit(coverage_utils.covered_main(
+    os.path.join(DEPOT_TOOLS_ROOT, 'git_dates.py')))