darcs2hg.py: use darcs patch hash as patch identifier

The use of the patch name is dangerous when duplicate names exist.
In case of a duplicate name the second patch and all its dependancies
are merged into a single mercurial patch.
The patch identifier (hash) is always unique.

contrib/darcs2hg.py

@@ -1,130 +1,131 b''
 #!/usr/bin/env python
 # Encoding: iso-8859-1
 # vim: tw=80 ts=4 sw=4 noet
 # -----------------------------------------------------------------------------
 # Project   : Basic Darcs to Mercurial conversion script
 # -----------------------------------------------------------------------------
 # Author    : Sebastien Pierre <[e-mail]>
 # Creation  : 24-May-2006
 # Last mod  : 26-May-2006
 # History   :
 #             26-May-2006 - Updated
 #             24-May-2006 - First implementation
 # -----------------------------------------------------------------------------
 
 import os, sys
 import tempfile
 import xml.dom.minidom as xml_dom
 from time import strptime, mktime
 
 DARCS_REPO = None
 HG_REPO    = None
 
 USAGE = """\
 %s DARCSREPO HGREPO
 
     Converts the given Darcs repository to a new Mercurial repository. The given
     HGREPO must not exist, as it will be created and filled up (this will avoid
     overwriting valuable data.
 
 """ % (os.path.basename(sys.argv[0]))
 
 # ------------------------------------------------------------------------------
 #
 # Utilities
 #
 # ------------------------------------------------------------------------------
 
 def cmd(text, path=None):
 	"""Executes a command, in the given directory (if any), and returns the
 	command result as a string."""
 	cwd = None
 	if path:
 		path = os.path.abspath(path)
 		cwd  = os.getcwd()
 		os.chdir(path)
 	print text
 	res = os.popen(text).read()
 	if path:
 		os.chdir(cwd)
 	return res
 
 def writefile(path, data):
 	"""Writes the given data into the given file."""
 	f = file(path, "w") ; f.write(data)  ; f.close()
 
 # ------------------------------------------------------------------------------
 #
 # Darcs interface
 #
 # ------------------------------------------------------------------------------
 
 def darcs_changes(darcsRepo):
 	"""Gets the changes list from the given darcs repository. This returns the
 	chronological list of changes as (change name, change summary)."""
 	changes    = cmd("darcs changes --reverse --xml-output", darcsRepo)
 	doc        = xml_dom.parseString(changes)
 	res        = []
 	for patch_node in doc.childNodes[0].childNodes:
 		name = filter(lambda n:n.nodeName == "name", patch_node.childNodes)
 		comm = filter(lambda n:n.nodeName == "comment", patch_node.childNodes)
 		if not name:continue
 		else: name = name[0].childNodes[0].data
 		if not comm: comm = ""
 		else: comm = comm[0].childNodes[0].data
 		author = patch_node.getAttribute("author")
 		date = patch_node.getAttribute("date")
-		yield author, date, name, comm
+        hash = patch_node.getAttribute("hash")
+        yield hash, author, date, name, comm
 
 def darcs_pull(hg_repo, darcs_repo, change):
 	cmd("darcs pull '%s' --all --patches='%s'" % (darcs_repo, change), hg_repo)
 
 # ------------------------------------------------------------------------------
 #
 # Mercurial interface
 #
 # ------------------------------------------------------------------------------
 
 def hg_commit( hg_repo, text, author, date ):
 	fd, tmpfile = tempfile.mkstemp(prefix="darcs2hg_")
 	writefile(tmpfile, text)
 	cmd("hg add -X _darcs", hg_repo)
 	cmd("hg remove -X _darcs --after", hg_repo)
 	cmd("hg commit -l %s -u '%s' -d '%s 0'"  % (tmpfile, author, date), hg_repo)
 	os.unlink(tmpfile)
 
 # ------------------------------------------------------------------------------
 #
 # Main
 #
 # ------------------------------------------------------------------------------
 
 if __name__ == "__main__":
 	args = sys.argv[1:]
 	# We parse the arguments
 	if len(args)   == 2:
 		darcs_repo = os.path.abspath(args[0])
 		hg_repo    = os.path.abspath(args[1])
 	else:
 		print USAGE
 		sys.exit(-1)
 	# Initializes the target repo
 	if not os.path.isdir(darcs_repo + "/_darcs"):
 		print "No darcs directory found at: " + darc_repo
 		sys.exit(-1)
 	if not os.path.isdir(hg_repo):
 		os.mkdir(hg_repo)
 	else:
 		print "Given HG repository must not exist. It will be created"
 		sys.exit(-1)
 	cmd("hg init '%s'" % (hg_repo))
 	cmd("darcs initialize", hg_repo)
 	# Get the changes from the Darcs repository
-	for author, date, summary, description in darcs_changes(darcs_repo):
+	for hash, author, date, summary, description in darcs_changes(darcs_repo):
 		text = summary + "\n" + description
-		darcs_pull(hg_repo, darcs_repo, summary)
+		darcs_pull(hg_repo, darcs_repo, hash)
 		epoch = int(mktime(strptime(date, '%Y%m%d%H%M%S')))
 		hg_commit(hg_repo, text, author, epoch)
 
 # EOF