--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hgext/fastexport.py	Wed Sep 18 06:07:09 2019 +0200
@@ -0,0 +1,218 @@
+# Copyright 2020 Joerg Sonnenberger <joerg@bec.de>
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+"""export repositories as git fast-import stream"""
+
+# The format specification for fast-import streams can be found at
+# https://git-scm.com/docs/git-fast-import#_input_format
+
+from __future__ import absolute_import
+import re
+
+from mercurial.i18n import _
+from mercurial.node import hex, nullrev
+from mercurial.utils import stringutil
+from mercurial import (
+    error,
+    pycompat,
+    registrar,
+    scmutil,
+)
+from .convert import convcmd
+
+# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
+# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
+# be specifying the version(s) of Mercurial they are tested with, or
+# leave the attribute unspecified.
+testedwith = b"ships-with-hg-core"
+
+cmdtable = {}
+command = registrar.command(cmdtable)
+
+GIT_PERSON_PROHIBITED = re.compile(b'[<>\n"]')
+GIT_EMAIL_PROHIBITED = re.compile(b"[<> \n]")
+
+
+def convert_to_git_user(authormap, user, rev):
+    mapped_user = authormap.get(user, user)
+    user_person = stringutil.person(mapped_user)
+    user_email = stringutil.email(mapped_user)
+    if GIT_EMAIL_PROHIBITED.match(user_email) or GIT_PERSON_PROHIBITED.match(
+        user_person
+    ):
+        raise error.Abort(
+            _(b"Unable to parse user into person and email for revision " + rev)
+        )
+    if user_person:
+        return b'"' + user_person + b'" <' + user_email + b'>'
+    else:
+        return b"<" + user_email + b">"
+
+
+def convert_to_git_date(date):
+    timestamp, utcoff = date
+    tzsign = b"+" if utcoff < 0 else b"-"
+    if utcoff % 60 != 0:
+        raise error.Abort(
+            _(b"UTC offset in %b is not an integer number of seconds") % (date,)
+        )
+    utcoff = abs(utcoff) // 60
+    tzh = utcoff // 60
+    tzmin = utcoff % 60
+    return b"%d " % int(timestamp) + tzsign + b"%02d%02d" % (tzh, tzmin)
+
+
+def convert_to_git_ref(branch):
+    # XXX filter/map depending on git restrictions
+    return b"refs/heads/" + branch
+
+
+def write_data(buf, data, skip_newline):
+    buf.append(b"data %d\n" % len(data))
+    buf.append(data)
+    if not skip_newline or data[-1:] != b"\n":
+        buf.append(b"\n")
+
+
+def export_commit(ui, repo, rev, marks, authormap):
+    ctx = repo[rev]
+    revid = ctx.hex()
+    if revid in marks:
+        ui.warn(_(b"warning: revision %s already exported, skipped\n") % revid)
+        return
+    parents = [p for p in ctx.parents() if p.rev() != nullrev]
+    for p in parents:
+        if p.hex() not in marks:
+            ui.warn(
+                _(b"warning: parent %s of %s has not been exported, skipped\n")
+                % (p, revid)
+            )
+            return
+
+    # For all files modified by the commit, check if they have already
+    # been exported and otherwise dump the blob with the new mark.
+    for fname in ctx.files():
+        if fname not in ctx:
+            continue
+        filectx = ctx.filectx(fname)
+        filerev = hex(filectx.filenode())
+        if filerev not in marks:
+            mark = len(marks) + 1
+            marks[filerev] = mark
+            data = filectx.data()
+            buf = [b"blob\n", b"mark :%d\n" % mark]
+            write_data(buf, data, False)
+            ui.write(*buf, keepprogressbar=True)
+            del buf
+
+    # Assign a mark for the current revision for references by
+    # latter merge commits.
+    mark = len(marks) + 1
+    marks[revid] = mark
+
+    ref = convert_to_git_ref(ctx.branch())
+    buf = [
+        b"commit %s\n" % ref,
+        b"mark :%d\n" % mark,
+        b"committer %s %s\n"
+        % (
+            convert_to_git_user(authormap, ctx.user(), revid),
+            convert_to_git_date(ctx.date()),
+        ),
+    ]
+    write_data(buf, ctx.description(), True)
+    if parents:
+        buf.append(b"from :%d\n" % marks[parents[0].hex()])
+    if len(parents) == 2:
+        buf.append(b"merge :%d\n" % marks[parents[1].hex()])
+        p0ctx = repo[parents[0]]
+        files = ctx.manifest().diff(p0ctx.manifest())
+    else:
+        files = ctx.files()
+    filebuf = []
+    for fname in files:
+        if fname not in ctx:
+            filebuf.append((fname, b"D %s\n" % fname))
+        else:
+            filectx = ctx.filectx(fname)
+            filerev = filectx.filenode()
+            fileperm = b"755" if filectx.isexec() else b"644"
+            changed = b"M %s :%d %s\n" % (fileperm, marks[hex(filerev)], fname)
+            filebuf.append((fname, changed))
+    filebuf.sort()
+    buf.extend(changed for (fname, changed) in filebuf)
+    del filebuf
+    buf.append(b"\n")
+    ui.write(*buf, keepprogressbar=True)
+    del buf
+
+
+isrev = re.compile(b"^[0-9a-f]{40}$")
+
+
+@command(
+    b"fastexport",
+    [
+        (b"r", b"rev", [], _(b"revisions to export"), _(b"REV")),
+        (b"i", b"import-marks", b"", _(b"old marks file to read"), _(b"FILE")),
+        (b"e", b"export-marks", b"", _(b"new marks file to write"), _(b"FILE")),
+        (
+            b"A",
+            b"authormap",
+            b"",
+            _(b"remap usernames using this file"),
+            _(b"FILE"),
+        ),
+    ],
+    _(b"[OPTION]... [REV]..."),
+    helpcategory=command.CATEGORY_IMPORT_EXPORT,
+)
+def fastexport(ui, repo, *revs, **opts):
+    """export repository as git fast-import stream
+
+    This command lets you dump a repository as a human-readable text stream.
+    It can be piped into corresponding import routines like "git fast-import".
+    Incremental dumps can be created by using marks files.
+    """
+    opts = pycompat.byteskwargs(opts)
+
+    revs += tuple(opts.get(b"rev", []))
+    if not revs:
+        revs = scmutil.revrange(repo, [b":"])
+    else:
+        revs = scmutil.revrange(repo, revs)
+    if not revs:
+        raise error.Abort(_(b"no revisions matched"))
+    authorfile = opts.get(b"authormap")
+    if authorfile:
+        authormap = convcmd.readauthormap(ui, authorfile)
+    else:
+        authormap = {}
+
+    import_marks = opts.get(b"import_marks")
+    marks = {}
+    if import_marks:
+        with open(import_marks, "rb") as import_marks_file:
+            for line in import_marks_file:
+                line = line.strip()
+                if not isrev.match(line) or line in marks:
+                    raise error.Abort(_(b"Corrupted marks file"))
+                marks[line] = len(marks) + 1
+
+    revs.sort()
+    with ui.makeprogress(
+        _(b"exporting"), unit=_(b"revisions"), total=len(revs)
+    ) as progress:
+        for rev in revs:
+            export_commit(ui, repo, rev, marks, authormap)
+            progress.increment()
+
+    export_marks = opts.get(b"export_marks")
+    if export_marks:
+        with open(export_marks, "wb") as export_marks_file:
+            output_marks = [None] * len(marks)
+            for k, v in marks.items():
+                output_marks[v - 1] = k
+            for k in output_marks:
+                export_marks_file.write(k + b"\n")