Fix git symbolic-ref warning on initial clone
[gitweb.git] / contrib / fast-import / git-p4
index e653e8cd37aa0336fb97ce4f11265f2e23b8f914..35a513fcb8bab6e7c51d9963138f00e09b58f4b6 100755 (executable)
@@ -7,7 +7,17 @@
 #            2007 Trolltech ASA
 # License: MIT <http://www.opensource.org/licenses/mit-license.php>
 #
-# TODO: Add an option to sync/rebase to fetch and rebase from origin first.
+# TODO: * implement git-p4 rollback <perforce change number> for debugging
+#         to roll back all p4 remote branches to a commit older or equal to
+#         the specified change.
+#       * for git-p4 submit --direct it would be nice to still create a
+#         git commit without updating HEAD before submitting to perforce.
+#         With the commit sha1 printed (or recoded in a .git/foo file?)
+#         it's possible to recover if anything goes wrong instead of potentially
+#         loosing a change entirely because it was never comitted to git and
+#         the p4 submit failed (or resulted in lots of conflicts, etc.)
+#       * Consider making --with-origin the default, assuming that the git
+#         protocol is always more efficient. (needs manual testing first :)
 #
 
 import optparse, sys, os, marshal, popen2, subprocess, shelve
@@ -45,6 +55,8 @@ def p4Where(depotPath):
     if not depotPath.endswith("/"):
         depotPath += "/"
     output = p4Cmd("where %s..." % depotPath)
+    if output["code"] == "error":
+        return ""
     clientPath = ""
     if "path" in output:
         clientPath = output.get("path")
@@ -139,6 +151,7 @@ class P4Submit(Command):
                 optparse.make_option("--log-substitutions", dest="substFile"),
                 optparse.make_option("--noninteractive", action="store_false"),
                 optparse.make_option("--dry-run", action="store_true"),
+                optparse.make_option("--direct", dest="directSubmit", action="store_true"),
         ]
         self.description = "Submit changes from git to the perforce depot."
         self.usage += " [name of git branch to submit into perforce depot]"
@@ -149,6 +162,7 @@ class P4Submit(Command):
         self.substFile = ""
         self.firstTime = True
         self.origin = ""
+        self.directSubmit = False
 
         self.logSubstitutions = {}
         self.logSubstitutions["<enter description here>"] = "%log%"
@@ -163,9 +177,12 @@ class P4Submit(Command):
             die("Cannot start sync. Previous sync config found at %s\nIf you want to start submitting again from scratch maybe you want to call git-p4 submit --reset" % self.configFile)
 
         commits = []
-        for line in mypopen("git rev-list --no-merges %s..%s" % (self.origin, self.master)).readlines():
-            commits.append(line[:-1])
-        commits.reverse()
+        if self.directSubmit:
+            commits.append("0")
+        else:
+            for line in mypopen("git rev-list --no-merges %s..%s" % (self.origin, self.master)).readlines():
+                commits.append(line[:-1])
+            commits.reverse()
 
         self.config["commits"] = commits
 
@@ -193,8 +210,12 @@ class P4Submit(Command):
         return result
 
     def apply(self, id):
-        print "Applying %s" % (mypopen("git log --max-count=1 --pretty=oneline %s" % id).read())
-        diff = mypopen("git diff-tree -r --name-status \"%s^\" \"%s\"" % (id, id)).readlines()
+        if self.directSubmit:
+            print "Applying local change in working directory/index"
+            diff = self.diffStatus
+        else:
+            print "Applying %s" % (mypopen("git log --max-count=1 --pretty=oneline %s" % id).read())
+            diff = mypopen("git diff-tree -r --name-status \"%s^\" \"%s\"" % (id, id)).readlines()
         filesToAdd = set()
         filesToDelete = set()
         editedFiles = set()
@@ -215,10 +236,15 @@ class P4Submit(Command):
             else:
                 die("unknown modifier %s for %s" % (modifier, path))
 
-        diffcmd = "git diff-tree -p --diff-filter=ACMRTUXB \"%s^\" \"%s\"" % (id, id)
-        patchcmd = diffcmd + " | patch -p1"
+        if self.directSubmit:
+            diffcmd = "cat \"%s\"" % self.diffFile
+        else:
+            diffcmd = "git format-patch -k --stdout \"%s^\"..\"%s\"" % (id, id)
+        patchcmd = diffcmd + " | git apply "
+        tryPatchCmd = patchcmd + "--check -"
+        applyPatchCmd = patchcmd + "--check --apply -"
 
-        if os.system(patchcmd + " --dry-run --silent") != 0:
+        if os.system(tryPatchCmd) != 0:
             print "Unfortunately applying the change failed!"
             print "What do you want to do?"
             response = "x"
@@ -228,7 +254,7 @@ class P4Submit(Command):
                 print "Skipping! Good luck with the next patches..."
                 return
             elif response == "a":
-                os.system(patchcmd)
+                os.system(applyPatchCmd)
                 if len(filesToAdd) > 0:
                     print "You may also want to call p4 add on the following files:"
                     print " ".join(filesToAdd)
@@ -241,7 +267,7 @@ class P4Submit(Command):
                 print "Patch saved to patch.txt in %s !" % self.clientPath
                 die("Please resolve and submit the conflict manually and continue afterwards with git-p4 submit --continue")
 
-        system(patchcmd)
+        system(applyPatchCmd)
 
         for f in filesToAdd:
             system("p4 add %s" % f)
@@ -249,9 +275,11 @@ class P4Submit(Command):
             system("p4 revert %s" % f)
             system("p4 delete %s" % f)
 
-        logMessage = extractLogMessageFromGitCommit(id)
-        logMessage = logMessage.replace("\n", "\n\t")
-        logMessage = logMessage[:-1]
+        logMessage = ""
+        if not self.directSubmit:
+            logMessage = extractLogMessageFromGitCommit(id)
+            logMessage = logMessage.replace("\n", "\n\t")
+            logMessage = logMessage[:-1]
 
         template = mypopen("p4 change -o").read()
 
@@ -355,6 +383,15 @@ class P4Submit(Command):
 
         print "Perforce checkout for depot path %s located at %s" % (depotPath, self.clientPath)
         oldWorkingDirectory = os.getcwd()
+
+        if self.directSubmit:
+            self.diffStatus = mypopen("git diff -r --name-status HEAD").readlines()
+            patch = mypopen("git diff -p --binary --diff-filter=ACMRTUXB HEAD").read()
+            self.diffFile = gitdir + "/p4-git-diff"
+            f = open(self.diffFile, "wb")
+            f.write(patch)
+            f.close();
+
         os.chdir(self.clientPath)
         response = raw_input("Do you want to sync %s with p4 sync? [y]es/[n]o " % self.clientPath)
         if response == "y" or response == "yes":
@@ -394,14 +431,25 @@ class P4Submit(Command):
 
         self.config.close()
 
+        if self.directSubmit:
+            os.remove(self.diffFile)
+
         if len(commits) == 0:
             if self.firstTime:
                 print "No changes found to apply between %s and current HEAD" % self.origin
             else:
                 print "All changes applied!"
-                response = raw_input("Do you want to sync from Perforce now using git-p4 rebase? [y]es/[n]o ")
+                response = ""
+                os.chdir(oldWorkingDirectory)
+
+                if self.directSubmit:
+                    response = raw_input("Do you want to DISCARD your git WORKING DIRECTORY CHANGES and sync from Perforce now using git-p4 rebase? [y]es/[n]o ")
+                    if response == "y" or response == "yes":
+                        system("git reset --hard")
+
+                if len(response) == 0:
+                    response = raw_input("Do you want to sync from Perforce now using git-p4 rebase? [y]es/[n]o ")
                 if response == "y" or response == "yes":
-                    os.chdir(oldWorkingDirectory)
                     rebase = P4Rebase()
                     rebase.run([])
             os.remove(self.configFile)
@@ -416,11 +464,9 @@ class P4Sync(Command):
                 optparse.make_option("--detect-branches", dest="detectBranches", action="store_true"),
                 optparse.make_option("--changesfile", dest="changesFile"),
                 optparse.make_option("--silent", dest="silent", action="store_true"),
-                optparse.make_option("--known-branches", dest="knownBranches"),
-                optparse.make_option("--data-cache", dest="dataCache", action="store_true"),
-                optparse.make_option("--command-cache", dest="commandCache", action="store_true"),
                 optparse.make_option("--detect-labels", dest="detectLabels", action="store_true"),
-                optparse.make_option("--with-origin", dest="syncWithOrigin", action="store_true")
+                optparse.make_option("--with-origin", dest="syncWithOrigin", action="store_true"),
+                optparse.make_option("--verbose", dest="verbose", action="store_true")
         ]
         self.description = """Imports from Perforce into a git repository.\n
     example:
@@ -432,10 +478,7 @@ class P4Sync(Command):
 
         self.usage += " //depot/path[@revRange]"
 
-        self.dataCache = False
-        self.commandCache = False
         self.silent = False
-        self.knownBranches = Set()
         self.createdBranches = Set()
         self.committedChanges = Set()
         self.branch = ""
@@ -443,6 +486,7 @@ class P4Sync(Command):
         self.detectLabels = False
         self.changesFile = ""
         self.syncWithOrigin = False
+        self.verbose = False
 
     def p4File(self, depotPath):
         return os.popen("p4 print -q \"%s\"" % depotPath, "rb").read()
@@ -467,124 +511,48 @@ class P4Sync(Command):
             fnum = fnum + 1
         return files
 
-    def isSubPathOf(self, first, second):
-        if not first.startswith(second):
-            return False
-        if first == second:
-            return True
-        return first[len(second)] == "/"
-
-    def branchesForCommit(self, files):
-        branches = Set()
-
-        for file in files:
-            relativePath = file["path"][len(self.depotPath):]
-            # strip off the filename
-            relativePath = relativePath[0:relativePath.rfind("/")]
-
-    #        if len(branches) == 0:
-    #            branches.add(relativePath)
-    #            knownBranches.add(relativePath)
-    #            continue
-
-            ###### this needs more testing :)
-            knownBranch = False
-            for branch in branches:
-                if relativePath == branch:
-                    knownBranch = True
-                    break
-    #            if relativePath.startswith(branch):
-                if self.isSubPathOf(relativePath, branch):
-                    knownBranch = True
-                    break
-    #            if branch.startswith(relativePath):
-                if self.isSubPathOf(branch, relativePath):
-                    branches.remove(branch)
-                    break
+    def splitFilesIntoBranches(self, commit):
+        branches = {}
 
-            if knownBranch:
+        fnum = 0
+        while commit.has_key("depotFile%s" % fnum):
+            path =  commit["depotFile%s" % fnum]
+            if not path.startswith(self.depotPath):
+    #            if not self.silent:
+    #                print "\nchanged files: ignoring path %s outside of %s in change %s" % (path, self.depotPath, change)
+                fnum = fnum + 1
                 continue
 
-            for branch in self.knownBranches:
-                #if relativePath.startswith(branch):
-                if self.isSubPathOf(relativePath, branch):
-                    if len(branches) == 0:
-                        relativePath = branch
-                    else:
-                        knownBranch = True
-                    break
+            file = {}
+            file["path"] = path
+            file["rev"] = commit["rev%s" % fnum]
+            file["action"] = commit["action%s" % fnum]
+            file["type"] = commit["type%s" % fnum]
+            fnum = fnum + 1
 
-            if knownBranch:
-                continue
+            relPath = path[len(self.depotPath):]
 
-            branches.add(relativePath)
-            self.knownBranches.add(relativePath)
+            for branch in self.knownBranches.keys():
+                if relPath.startswith(branch):
+                    if branch not in branches:
+                        branches[branch] = []
+                    branches[branch].append(file)
 
         return branches
 
-    def findBranchParent(self, branchPrefix, files):
-        for file in files:
-            path = file["path"]
-            if not path.startswith(branchPrefix):
-                continue
-            action = file["action"]
-            if action != "integrate" and action != "branch":
-                continue
-            rev = file["rev"]
-            depotPath = path + "#" + rev
-
-            log = p4CmdList("filelog \"%s\"" % depotPath)
-            if len(log) != 1:
-                print "eek! I got confused by the filelog of %s" % depotPath
-                sys.exit(1);
-
-            log = log[0]
-            if log["action0"] != action:
-                print "eek! wrong action in filelog for %s : found %s, expected %s" % (depotPath, log["action0"], action)
-                sys.exit(1);
-
-            branchAction = log["how0,0"]
-    #        if branchAction == "branch into" or branchAction == "ignored":
-    #            continue # ignore for branching
-
-            if not branchAction.endswith(" from"):
-                continue # ignore for branching
-    #            print "eek! file %s was not branched from but instead: %s" % (depotPath, branchAction)
-    #            sys.exit(1);
-
-            source = log["file0,0"]
-            if source.startswith(branchPrefix):
-                continue
-
-            lastSourceRev = log["erev0,0"]
-
-            sourceLog = p4CmdList("filelog -m 1 \"%s%s\"" % (source, lastSourceRev))
-            if len(sourceLog) != 1:
-                print "eek! I got confused by the source filelog of %s%s" % (source, lastSourceRev)
-                sys.exit(1);
-            sourceLog = sourceLog[0]
-
-            relPath = source[len(self.depotPath):]
-            # strip off the filename
-            relPath = relPath[0:relPath.rfind("/")]
-
-            for branch in self.knownBranches:
-                if self.isSubPathOf(relPath, branch):
-    #                print "determined parent branch branch %s due to change in file %s" % (branch, source)
-                    return branch
-    #            else:
-    #                print "%s is not a subpath of branch %s" % (relPath, branch)
-
-        return ""
-
-    def commit(self, details, files, branch, branchPrefix, parent = "", merged = ""):
+    def commit(self, details, files, branch, branchPrefix, parent = ""):
         epoch = details["time"]
         author = details["user"]
 
+        if self.verbose:
+            print "commit into %s" % branch
+
         self.gitStream.write("commit %s\n" % branch)
     #    gitStream.write("mark :%s\n" % details["change"])
         self.committedChanges.add(int(details["change"]))
         committer = ""
+        if author not in self.users:
+            self.getUserMapFromPerforceServer()
         if author in self.users:
             committer = "%s %s %s" % (self.users[author], epoch, self.tz)
         else:
@@ -598,11 +566,10 @@ class P4Sync(Command):
         self.gitStream.write("EOT\n\n")
 
         if len(parent) > 0:
+            if self.verbose:
+                print "parent %s" % parent
             self.gitStream.write("from %s\n" % parent)
 
-        if len(merged) > 0:
-            self.gitStream.write("merge %s\n" % merged)
-
         for file in files:
             path = file["path"]
             if not path.startswith(branchPrefix):
@@ -636,12 +603,12 @@ class P4Sync(Command):
 
         change = int(details["change"])
 
-        self.lastChange = change
-
-        if change in self.labels:
+        if self.labels.has_key(change):
             label = self.labels[change]
             labelDetails = label[0]
             labelRevisions = label[1]
+            if self.verbose:
+                print "Change %s is labelled %s" % (change, labelDetails)
 
             files = p4CmdList("files %s...@%s" % (branchPrefix, change))
 
@@ -676,129 +643,7 @@ class P4Sync(Command):
                 if not self.silent:
                     print "Tag %s does not match with change %s: file count is different." % (labelDetails["label"], change)
 
-    def extractFilesInCommitToBranch(self, files, branchPrefix):
-        newFiles = []
-
-        for file in files:
-            path = file["path"]
-            if path.startswith(branchPrefix):
-                newFiles.append(file)
-
-        return newFiles
-
-    def findBranchSourceHeuristic(self, files, branch, branchPrefix):
-        for file in files:
-            action = file["action"]
-            if action != "integrate" and action != "branch":
-                continue
-            path = file["path"]
-            rev = file["rev"]
-            depotPath = path + "#" + rev
-
-            log = p4CmdList("filelog \"%s\"" % depotPath)
-            if len(log) != 1:
-                print "eek! I got confused by the filelog of %s" % depotPath
-                sys.exit(1);
-
-            log = log[0]
-            if log["action0"] != action:
-                print "eek! wrong action in filelog for %s : found %s, expected %s" % (depotPath, log["action0"], action)
-                sys.exit(1);
-
-            branchAction = log["how0,0"]
-
-            if not branchAction.endswith(" from"):
-                continue # ignore for branching
-    #            print "eek! file %s was not branched from but instead: %s" % (depotPath, branchAction)
-    #            sys.exit(1);
-
-            source = log["file0,0"]
-            if source.startswith(branchPrefix):
-                continue
-
-            lastSourceRev = log["erev0,0"]
-
-            sourceLog = p4CmdList("filelog -m 1 \"%s%s\"" % (source, lastSourceRev))
-            if len(sourceLog) != 1:
-                print "eek! I got confused by the source filelog of %s%s" % (source, lastSourceRev)
-                sys.exit(1);
-            sourceLog = sourceLog[0]
-
-            relPath = source[len(self.depotPath):]
-            # strip off the filename
-            relPath = relPath[0:relPath.rfind("/")]
-
-            for candidate in self.knownBranches:
-                if self.isSubPathOf(relPath, candidate) and candidate != branch:
-                    return candidate
-
-        return ""
-
-    def changeIsBranchMerge(self, sourceBranch, destinationBranch, change):
-        sourceFiles = {}
-        for file in p4CmdList("files %s...@%s" % (self.depotPath + sourceBranch + "/", change)):
-            if file["action"] == "delete":
-                continue
-            sourceFiles[file["depotFile"]] = file
-
-        destinationFiles = {}
-        for file in p4CmdList("files %s...@%s" % (self.depotPath + destinationBranch + "/", change)):
-            destinationFiles[file["depotFile"]] = file
-
-        for fileName in sourceFiles.keys():
-            integrations = []
-            deleted = False
-            integrationCount = 0
-            for integration in p4CmdList("integrated \"%s\"" % fileName):
-                toFile = integration["fromFile"] # yes, it's true, it's fromFile
-                if not toFile in destinationFiles:
-                    continue
-                destFile = destinationFiles[toFile]
-                if destFile["action"] == "delete":
-    #                print "file %s has been deleted in %s" % (fileName, toFile)
-                    deleted = True
-                    break
-                integrationCount += 1
-                if integration["how"] == "branch from":
-                    continue
-
-                if int(integration["change"]) == change:
-                    integrations.append(integration)
-                    continue
-                if int(integration["change"]) > change:
-                    continue
-
-                destRev = int(destFile["rev"])
-
-                startRev = integration["startFromRev"][1:]
-                if startRev == "none":
-                    startRev = 0
-                else:
-                    startRev = int(startRev)
-
-                endRev = integration["endFromRev"][1:]
-                if endRev == "none":
-                    endRev = 0
-                else:
-                    endRev = int(endRev)
-
-                initialBranch = (destRev == 1 and integration["how"] != "branch into")
-                inRange = (destRev >= startRev and destRev <= endRev)
-                newer = (destRev > startRev and destRev > endRev)
-
-                if initialBranch or inRange or newer:
-                    integrations.append(integration)
-
-            if deleted:
-                continue
-
-            if len(integrations) == 0 and integrationCount > 1:
-                print "file %s was not integrated from %s into %s" % (fileName, sourceBranch, destinationBranch)
-                return False
-
-        return True
-
-    def getUserMap(self):
+    def getUserMapFromPerforceServer(self):
         self.users = {}
 
         for output in p4CmdList("users"):
@@ -806,6 +651,23 @@ class P4Sync(Command):
                 continue
             self.users[output["User"]] = output["FullName"] + " <" + output["Email"] + ">"
 
+        cache = open(gitdir + "/p4-usercache.txt", "wb")
+        for user in self.users.keys():
+            cache.write("%s\t%s\n" % (user, self.users[user]))
+        cache.close();
+
+    def loadUserMapFromCache(self):
+        self.users = {}
+        try:
+            cache = open(gitdir + "/p4-usercache.txt", "rb")
+            lines = cache.readlines()
+            cache.close()
+            for line in lines:
+                entry = line[:-1].split("\t")
+                self.users[entry[0]] = entry[1]
+        except IOError:
+            self.getUserMapFromPerforceServer()
+
     def getLabels(self):
         self.labels = {}
 
@@ -817,7 +679,9 @@ class P4Sync(Command):
             label = output["label"]
             revisions = {}
             newestChange = 0
-            for file in p4CmdList("files //...@%s" % label):
+            if self.verbose:
+                print "Querying files for label %s" % label
+            for file in p4CmdList("files %s...@%s" % (self.depotPath, label)):
                 revisions[file["depotFile"]] = file["rev"]
                 change = int(file["change"])
                 if change > newestChange:
@@ -825,15 +689,54 @@ class P4Sync(Command):
 
             self.labels[newestChange] = [output, revisions]
 
+        if self.verbose:
+            print "Label changes: %s" % self.labels.keys()
+
+    def getBranchMapping(self):
+        self.projectName = self.depotPath[self.depotPath[:-1].rfind("/") + 1:]
+
+        for info in p4CmdList("branches"):
+            details = p4Cmd("branch -o %s" % info["branch"])
+            viewIdx = 0
+            while details.has_key("View%s" % viewIdx):
+                paths = details["View%s" % viewIdx].split(" ")
+                viewIdx = viewIdx + 1
+                # require standard //depot/foo/... //depot/bar/... mapping
+                if len(paths) != 2 or not paths[0].endswith("/...") or not paths[1].endswith("/..."):
+                    continue
+                source = paths[0]
+                destination = paths[1]
+                if source.startswith(self.depotPath) and destination.startswith(self.depotPath):
+                    source = source[len(self.depotPath):-4]
+                    destination = destination[len(self.depotPath):-4]
+                    if destination not in self.knownBranches:
+                        self.knownBranches[destination] = source
+                    if source not in self.knownBranches:
+                        self.knownBranches[source] = source
+
+    def listExistingP4GitBranches(self):
+        self.p4BranchesInGit = []
+
+        for line in mypopen("git rev-parse --symbolic --remotes").readlines():
+            if line.startswith("p4/") and line != "p4/HEAD\n":
+                branch = line[3:-1]
+                self.p4BranchesInGit.append(branch)
+                self.initialParents["refs/remotes/p4/" + branch] = parseRevision(line[:-1])
+
     def run(self, args):
         self.depotPath = ""
         self.changeRange = ""
         self.initialParent = ""
         self.previousDepotPath = ""
-        # importing into default remotes/p4/* layout?
-        defaultImport = False
+        # map from branch depot path to parent branch
+        self.knownBranches = {}
+        self.initialParents = {}
+
+        createP4HeadRef = False;
+
+        if self.syncWithOrigin and gitBranchExists("origin") and gitBranchExists("refs/remotes/p4/master") and not self.detectBranches:
+            ### needs to be ported to multi branch import
 
-        if self.syncWithOrigin and gitBranchExists("origin") and gitBranchExists("refs/remotes/p4/master"):
             print "Syncing with origin first as requested by calling git fetch origin"
             system("git fetch origin")
             [originPreviousDepotPath, originP4Change] = extractDepotPathAndChangeFromGitLog(extractLogMessageFromGitCommit("origin"))
@@ -852,29 +755,55 @@ class P4Sync(Command):
             self.branch = "refs/remotes/p4/master"
             if gitBranchExists("refs/heads/p4"):
                 system("git update-ref %s refs/heads/p4" % self.branch)
-                system("git symbolic-ref refs/remotes/p4/HEAD refs/remotes/p4/master")
                 system("git branch -D p4");
-            else:
-                defaultImport = True
+            # create it /after/ importing, when master exists
+            if not gitBranchExists("refs/remotes/p4/HEAD"):
+                createP4HeadRef = True
+
+        # this needs to be called after the conversion from heads/p4 to remotes/p4/master
+        self.listExistingP4GitBranches()
+        if len(self.p4BranchesInGit) > 1 and not self.silent:
+            print "Importing from/into multiple branches"
+            self.detectBranches = True
 
         if len(args) == 0:
-            if not gitBranchExists(self.branch) and gitBranchExists("origin"):
+            if not gitBranchExists(self.branch) and gitBranchExists("origin") and not self.detectBranches:
+                ### needs to be ported to multi branch import
                 if not self.silent:
                     print "Creating %s branch in git repository based on origin" % self.branch
                 branch = self.branch
                 if not branch.startswith("refs"):
                     branch = "refs/heads/" + branch
                 system("git update-ref %s origin" % branch)
-                if defaultImport:
-                    system("git symbolic-ref refs/remotes/p4/HEAD %s" % branch)
 
-            [self.previousDepotPath, p4Change] = extractDepotPathAndChangeFromGitLog(extractLogMessageFromGitCommit(self.branch))
-            if len(self.previousDepotPath) > 0 and len(p4Change) > 0:
-                p4Change = int(p4Change) + 1
+            if self.verbose:
+                print "branches: %s" % self.p4BranchesInGit
+
+            p4Change = 0
+            for branch in self.p4BranchesInGit:
+                depotPath, change = extractDepotPathAndChangeFromGitLog(extractLogMessageFromGitCommit("refs/remotes/p4/" + branch))
+
+                if self.verbose:
+                    print "path %s change %s" % (depotPath, change)
+
+                if len(depotPath) > 0 and len(change) > 0:
+                    change = int(change) + 1
+                    p4Change = max(p4Change, change)
+
+                    if len(self.previousDepotPath) == 0:
+                        self.previousDepotPath = depotPath
+                    else:
+                        i = 0
+                        l = min(len(self.previousDepotPath), len(depotPath))
+                        while i < l and self.previousDepotPath[i] == depotPath[i]:
+                            i = i + 1
+                        self.previousDepotPath = self.previousDepotPath[:i]
+
+            if p4Change > 0:
                 self.depotPath = self.previousDepotPath
                 self.changeRange = "@%s,#head" % p4Change
                 self.initialParent = parseRevision(self.branch)
-                if not self.silent:
+                if not self.silent and not self.detectBranches:
                     print "Performing incremental import into %s git branch" % self.branch
 
         if not self.branch.startswith("refs/"):
@@ -896,7 +825,6 @@ class P4Sync(Command):
 
         self.revision = ""
         self.users = {}
-        self.lastChange = 0
 
         if self.depotPath.find("@") != -1:
             atIdx = self.depotPath.index("@")
@@ -920,11 +848,21 @@ class P4Sync(Command):
         if not self.depotPath.endswith("/"):
             self.depotPath += "/"
 
-        self.getUserMap()
+        self.loadUserMapFromCache()
         self.labels = {}
         if self.detectLabels:
             self.getLabels();
 
+        if self.detectBranches:
+            self.getBranchMapping();
+            if self.verbose:
+                print "p4-git branches: %s" % self.p4BranchesInGit
+                print "initial parents: %s" % self.initialParents
+            for b in self.p4BranchesInGit:
+                if b != "master":
+                    b = b[len(self.projectName):]
+                self.createdBranches.add(b)
+
         self.tz = "%+03d%02d" % (- time.timezone / 3600, ((- time.timezone % 3600) / 60))
 
         importProcess = subprocess.Popen(["git", "fast-import"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE);
@@ -978,6 +916,8 @@ class P4Sync(Command):
 
                 changes.sort()
             else:
+                if self.verbose:
+                    print "Getting p4 changes for %s...%s" % (self.depotPath, self.changeRange)
                 output = mypopen("p4 changes %s...%s" % (self.depotPath, self.changeRange)).readlines()
 
                 for line in output:
@@ -988,66 +928,91 @@ class P4Sync(Command):
 
             if len(changes) == 0:
                 if not self.silent:
-                    print "no changes to import!"
+                    print "No changes to import!"
                 return True
 
+            self.updatedBranches = set()
+
             cnt = 1
             for change in changes:
                 description = p4Cmd("describe %s" % change)
 
                 if not self.silent:
-                    sys.stdout.write("\rimporting revision %s (%s%%)" % (change, cnt * 100 / len(changes)))
+                    sys.stdout.write("\rImporting revision %s (%s%%)" % (change, cnt * 100 / len(changes)))
                     sys.stdout.flush()
                 cnt = cnt + 1
 
                 try:
-                    files = self.extractFilesFromCommit(description)
                     if self.detectBranches:
-                        for branch in self.branchesForCommit(files):
-                            self.knownBranches.add(branch)
+                        branches = self.splitFilesIntoBranches(description)
+                        for branch in branches.keys():
                             branchPrefix = self.depotPath + branch + "/"
 
-                            filesForCommit = self.extractFilesInCommitToBranch(files, branchPrefix)
-
-                            merged = ""
                             parent = ""
-                            ########### remove cnt!!!
-                            if branch not in self.createdBranches and cnt > 2:
+
+                            filesForCommit = branches[branch]
+
+                            if self.verbose:
+                                print "branch is %s" % branch
+
+                            self.updatedBranches.add(branch)
+
+                            if branch not in self.createdBranches:
                                 self.createdBranches.add(branch)
-                                parent = self.findBranchParent(branchPrefix, files)
+                                parent = self.knownBranches[branch]
                                 if parent == branch:
                                     parent = ""
-            #                    elif len(parent) > 0:
-            #                        print "%s branched off of %s" % (branch, parent)
+                                elif self.verbose:
+                                    print "parent determined through known branches: %s" % parent
+
+                            # main branch? use master
+                            if branch == "main":
+                                branch = "master"
+                            else:
+                                branch = self.projectName + branch
 
-                            if len(parent) == 0:
-                                merged = self.findBranchSourceHeuristic(filesForCommit, branch, branchPrefix)
-                                if len(merged) > 0:
-                                    print "change %s could be a merge from %s into %s" % (description["change"], merged, branch)
-                                    if not self.changeIsBranchMerge(merged, branch, int(description["change"])):
-                                        merged = ""
+                            if parent == "main":
+                                parent = "master"
+                            elif len(parent) > 0:
+                                parent = self.projectName + parent
 
-                            branch = "refs/heads/" + branch
+                            branch = "refs/remotes/p4/" + branch
                             if len(parent) > 0:
-                                parent = "refs/heads/" + parent
-                            if len(merged) > 0:
-                                merged = "refs/heads/" + merged
-                            self.commit(description, files, branch, branchPrefix, parent, merged)
+                                parent = "refs/remotes/p4/" + parent
+
+                            if self.verbose:
+                                print "looking for initial parent for %s; current parent is %s" % (branch, parent)
+
+                            if len(parent) == 0 and branch in self.initialParents:
+                                parent = self.initialParents[branch]
+                                del self.initialParents[branch]
+
+                            self.commit(description, filesForCommit, branch, branchPrefix, parent)
                     else:
+                        files = self.extractFilesFromCommit(description)
                         self.commit(description, files, self.branch, self.depotPath, self.initialParent)
                         self.initialParent = ""
                 except IOError:
                     print self.gitError.read()
                     sys.exit(1)
 
-        if not self.silent:
-            print ""
+            if not self.silent:
+                print ""
+                if len(self.updatedBranches) > 0:
+                    sys.stdout.write("Updated branches: ")
+                    for b in self.updatedBranches:
+                        sys.stdout.write("%s " % b)
+                    sys.stdout.write("\n")
 
 
         self.gitStream.close()
+        if importProcess.wait() != 0:
+            die("fast-import failed: %s" % self.gitError.read())
         self.gitOutput.close()
         self.gitError.close()
-        importProcess.wait()
+
+        if createP4HeadRef:
+            system("git symbolic-ref refs/remotes/p4/HEAD %s" % self.branch)
 
         return True
 
@@ -1076,6 +1041,8 @@ class P4Clone(P4Sync):
         self.needsGit = False
 
     def run(self, args):
+        global gitdir
+
         if len(args) < 1:
             return False
         depotPath = args[0]
@@ -1111,11 +1078,15 @@ class P4Clone(P4Sync):
         os.makedirs(dir)
         os.chdir(dir)
         system("git init")
+        gitdir = os.getcwd() + "/.git"
         if not P4Sync.run(self, [depotPath]):
             return False
         if self.branch != "master":
-            system("git branch master p4")
-            system("git checkout -f")
+            if gitBranchExists("refs/remotes/p4/master"):
+                system("git branch master refs/remotes/p4/master")
+                system("git checkout -f")
+            else:
+                print "Could not detect main branch. No checkout/master branch created."
         return True
 
 class HelpFormatter(optparse.IndentedHelpFormatter):