CVS convert: Find correct parent for new branch (issue704)

CVS convert: Find correct parent for new branch (issue704)

Previously the parent was determined by the last changeset where the branched
file was changed even if the branch is based on an earlier revision.
Fix written by mpm.

--- a/hgext/convert/cvs.py	Tue Jan 22 00:08:43 2008 +0100
+++ b/hgext/convert/cvs.py	Tue Jan 22 00:16:50 2008 +0100
@@ -49,11 +49,13 @@
             os.chdir(self.path)
             id = None
             state = 0
+            filerevids = {}
             for l in util.popen(cmd):
                 if state == 0: # header
                     if l.startswith("PatchSet"):
                         id = l[9:-2]
                         if maxrev and int(id) > maxrev:
+                            # ignore everything
                             state = 3
                     elif l.startswith("Date"):
                         date = util.parsedate(l[6:-1], ["%Y/%m/%d %H:%M:%S"])
@@ -64,7 +66,8 @@
                         self.lastbranch[branch] = id
                     elif l.startswith("Ancestor branch"):
                         ancestor = l[17:-1]
-                        self.parent[id] = self.lastbranch[ancestor]
+                        # figure out the parent later
+                        self.parent[id] = None
                     elif l.startswith("Author"):
                         author = self.recode(l[8:-1])
                     elif l.startswith("Tag:") or l.startswith("Tags:"):
@@ -73,23 +76,36 @@
                         if (len(t) > 1) or (t[0] and (t[0] != "(none)")):
                             self.tags.update(dict.fromkeys(t, id))
                     elif l.startswith("Log:"):
+                        # switch to gathering log
                         state = 1
                         log = ""
                 elif state == 1: # log
                     if l == "Members: \n":
+                        # switch to gathering members
                         files = {}
+                        oldrevs = []
                         log = self.recode(log[:-1])
                         state = 2
                     else:
+                        # gather log
                         log += l
-                elif state == 2:
-                    if l == "\n": #
+                elif state == 2: # members
+                    if l == "\n": # start of next entry
                         state = 0
                         p = [self.parent[id]]
                         if id == "1":
                             p = []
                         if branch == "HEAD":
                             branch = ""
+                        if branch and p[0] == None:
+                            latest = None
+                            # the last changeset that contains a base
+                            # file is our parent
+                            for r in oldrevs:
+                                latest = max(filerevids[r], latest)
+                            p = [latest]
+
+                        # add current commit to set
                         c = commit(author=author, date=date, parents=p,
                                    desc=log, branch=branch)
                         self.changeset[id] = c
@@ -98,9 +114,14 @@
                         colon = l.rfind(':')
                         file = l[1:colon]
                         rev = l[colon+1:-2]
-                        rev = rev.split("->")[1]
+                        oldrev, rev = rev.split("->")
                         files[file] = rev
+
+                        # save some information for identifying branch points
+                        oldrevs.append("%s:%s" % (oldrev, file))
+                        filerevids["%s:%s" % (rev, file)] = id
                 elif state == 3:
+                    # swallow all input
                     continue
 
             self.heads = self.lastbranch.values()

--- a/tests/test-convert-cvs.out	Tue Jan 22 00:08:43 2008 +0100
+++ b/tests/test-convert-cvs.out	Tue Jan 22 00:16:50 2008 +0100
@@ -101,12 +101,12 @@
 0 Initial revision files: b/c
 o  5 (branch) ci2 files: b/c
 |
-o  4 () ci1 files: a b/c
-|
-o  3 () update tags files: .hgtags
-|
-o  2 () ci0 files: b/c
-|
+| o  4 () ci1 files: a b/c
+| |
+| o  3 () update tags files: .hgtags
+| |
+| o  2 () ci0 files: b/c
+|/
 | o  1 (INITIAL) import files:
 |/
 o  0 () Initial revision files: a b/c