git-p4: add unshelve command

This can be used to "unshelve" a shelved P4 commit into
a git commit.

For example:

  $ git p4 unshelve 12345

The resulting commit ends up in the branch:
   refs/remotes/p4/unshelved/12345

If that branch already exists, it is renamed - for example
the above branch would be saved as p4/unshelved/12345.1.

git-p4 checks that the shelved changelist is based on files
which are at the same Perforce revision as the origin branch
being used for the unshelve (HEAD by default). If they are not,
it will refuse to unshelve. This is to ensure that the unshelved
change does not contain other changes mixed-in.

The reference branch can be changed manually with the "--origin"
option.

The change adds a new Unshelve command class. This just runs the
existing P4Sync code tweaked to handle a shelved changelist.

Signed-off-by: Luke Diamand <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: luked99

Documentation/git-p4.txt

@@ -164,6 +164,31 @@ $ git p4 submit --shelve
 $ git p4 submit --update-shelve 1234 --update-shelve 2345
 ----
 
+
+Unshelve
+~~~~~~~~
+Unshelving will take a shelved P4 changelist, and produce the equivalent git commit
+in the branch refs/remotes/p4/unshelved/<changelist>.
+
+The git commit is created relative to the current origin revision (HEAD by default).
+If the shelved changelist's parent revisions differ, git-p4 will refuse to unshelve;
+you need to be unshelving onto an equivalent tree.
+
+The origin revision can be changed with the "--origin" option.
+
+If the target branch in refs/remotes/p4/unshelved already exists, the old one will
+be renamed.
+
+----
+$ git p4 sync
+$ git p4 unshelve 12345
+$ git show refs/remotes/p4/unshelved/12345
+<submit more changes via p4 to the same files>
+$ git p4 unshelve 12345
+<refuses to unshelve until git is in sync with p4 again>
+
+----
+
 OPTIONS
 -------
 
@@ -337,6 +362,13 @@ These options can be used to modify 'git p4 rebase' behavior.
 --import-labels::
 	Import p4 labels.
 
+Unshelve options
+~~~~~~~~~~~~~~~~
+
+--origin::
+    Sets the git refspec against which the shelved P4 changelist is compared.
+    Defaults to p4/master.
+
 DEPOT PATH SYNTAX
 -----------------
 The p4 depot path argument to 'git p4 sync' and 'git p4 clone' can

git-p4.py

@@ -316,12 +316,17 @@ def p4_last_change():
     results = p4CmdList(["changes", "-m", "1"], skip_info=True)
     return int(results[0]['change'])
 
-def p4_describe(change):
+def p4_describe(change, shelved=False):
     """Make sure it returns a valid result by checking for
        the presence of field "time".  Return a dict of the
        results."""
 
-    ds = p4CmdList(["describe", "-s", str(change)], skip_info=True)
+    cmd = ["describe", "-s"]
+    if shelved:
+        cmd += ["-S"]
+    cmd += [str(change)]
+
+    ds = p4CmdList(cmd, skip_info=True)
     if len(ds) != 1:
         die("p4 describe -s %d did not return 1 result: %s" % (change, str(ds)))
 
@@ -662,6 +667,12 @@ def gitBranchExists(branch):
                             stderr=subprocess.PIPE, stdout=subprocess.PIPE);
     return proc.wait() == 0;
 
+def gitUpdateRef(ref, newvalue):
+    subprocess.check_call(["git", "update-ref", ref, newvalue])
+
+def gitDeleteRef(ref):
+    subprocess.check_call(["git", "update-ref", "-d", ref])
+
 _gitConfig = {}
 
 def gitConfig(key, typeSpecifier=None):
@@ -2411,6 +2422,7 @@ def __init__(self):
         self.tempBranches = []
         self.tempBranchLocation = "refs/git-p4-tmp"
         self.largeFileSystem = None
+        self.suppress_meta_comment = False
 
         if gitConfig('git-p4.largeFileSystem'):
             largeFileSystemConstructor = globals()[gitConfig('git-p4.largeFileSystem')]
@@ -2421,6 +2433,18 @@ def __init__(self):
         if gitConfig("git-p4.syncFromOrigin") == "false":
             self.syncWithOrigin = False
 
+        self.depotPaths = []
+        self.changeRange = ""
+        self.previousDepotPaths = []
+        self.hasOrigin = False
+
+        # map from branch depot path to parent branch
+        self.knownBranches = {}
+        self.initialParents = {}
+
+        self.tz = "%+03d%02d" % (- time.timezone / 3600, ((- time.timezone % 3600) / 60))
+        self.labels = {}
+
     # Force a checkpoint in fast-import and wait for it to finish
     def checkpoint(self):
         self.gitStream.write("checkpoint\n\n")
@@ -2429,7 +2453,20 @@ def checkpoint(self):
         if self.verbose:
             print "checkpoint finished: " + out
 
-    def extractFilesFromCommit(self, commit):
+    def cmp_shelved(self, path, filerev, revision):
+        """ Determine if a path at revision #filerev is the same as the file
+            at revision @revision for a shelved changelist. If they don't match,
+            unshelving won't be safe (we will get other changes mixed in).
+
+            This is comparing the revision that the shelved changelist is *based* on, not
+            the shelved changelist itself.
+        """
+        ret = p4Cmd(["diff2", "{0}#{1}".format(path, filerev), "{0}@{1}".format(path, revision)])
+        if verbose:
+            print("p4 diff2 path %s filerev %s revision %s => %s" % (path, filerev, revision, ret))
+        return ret["status"] == "identical"
+
+    def extractFilesFromCommit(self, commit, shelved=False, shelved_cl = 0, origin_revision = 0):
         self.cloneExclude = [re.sub(r"\.\.\.$", "", path)
                              for path in self.cloneExclude]
         files = []
@@ -2452,6 +2489,19 @@ def extractFilesFromCommit(self, commit):
             file["rev"] = commit["rev%s" % fnum]
             file["action"] = commit["action%s" % fnum]
             file["type"] = commit["type%s" % fnum]
+            if shelved:
+                file["shelved_cl"] = int(shelved_cl)
+
+                # For shelved changelists, check that the revision of each file that the
+                # shelve was based on matches the revision that we are using for the
+                # starting point for git-fast-import (self.initialParent). Otherwise
+                # the resulting diff will contain deltas from multiple commits.
+
+                if file["action"] != "add" and \
+                    not self.cmp_shelved(path, file["rev"], origin_revision):
+                    sys.exit("change {0} not based on {1} for {2}, cannot unshelve".format(
+                        commit["change"], self.initialParent, path))
+
             files.append(file)
             fnum = fnum + 1
         return files
@@ -2743,7 +2793,16 @@ def streamP4Files(self, files):
             def streamP4FilesCbSelf(entry):
                 self.streamP4FilesCb(entry)
 
-            fileArgs = ['%s#%s' % (f['path'], f['rev']) for f in filesToRead]
+            fileArgs = []
+            for f in filesToRead:
+                if 'shelved_cl' in f:
+                    # Handle shelved CLs using the "p4 print file@=N" syntax to print
+                    # the contents
+                    fileArg = '%s@=%d' % (f['path'], f['shelved_cl'])
+                else:
+                    fileArg = '%s#%s' % (f['path'], f['rev'])
+
+                fileArgs.append(fileArg)
 
             p4CmdList(["-x", "-", "print"],
                       stdin=fileArgs,
@@ -2844,11 +2903,15 @@ def commit(self, details, files, branch, parent = ""):
         self.gitStream.write(details["desc"])
         if len(jobs) > 0:
             self.gitStream.write("\nJobs: %s" % (' '.join(jobs)))
-        self.gitStream.write("\n[git-p4: depot-paths = \"%s\": change = %s" %
-                             (','.join(self.branchPrefixes), details["change"]))
-        if len(details['options']) > 0:
-            self.gitStream.write(": options = %s" % details['options'])
-        self.gitStream.write("]\nEOT\n\n")
+
+        if not self.suppress_meta_comment:
+            self.gitStream.write("\n[git-p4: depot-paths = \"%s\": change = %s" %
+                                (','.join(self.branchPrefixes), details["change"]))
+            if len(details['options']) > 0:
+                self.gitStream.write(": options = %s" % details['options'])
+            self.gitStream.write("]\n")
+
+        self.gitStream.write("EOT\n\n")
 
         if len(parent) > 0:
             if self.verbose:
@@ -3162,10 +3225,10 @@ def searchParent(self, parent, branch, target):
         else:
             return None
 
-    def importChanges(self, changes):
+    def importChanges(self, changes, shelved=False, origin_revision=0):
         cnt = 1
         for change in changes:
-            description = p4_describe(change)
+            description = p4_describe(change, shelved)
             self.updateOptionDict(description)
 
             if not self.silent:
@@ -3235,7 +3298,7 @@ def importChanges(self, changes):
                                 print "Parent of %s not found. Committing into head of %s" % (branch, parent)
                             self.commit(description, filesForCommit, branch, parent)
                 else:
-                    files = self.extractFilesFromCommit(description)
+                    files = self.extractFilesFromCommit(description, shelved, change, origin_revision)
                     self.commit(description, files, self.branch,
                                 self.initialParent)
                     # only needed once, to connect to the previous commit
@@ -3300,17 +3363,23 @@ def importHeadRevision(self, revision):
             print "IO error with git fast-import. Is your git version recent enough?"
             print self.gitError.read()
 
+    def openStreams(self):
+        self.importProcess = subprocess.Popen(["git", "fast-import"],
+                                              stdin=subprocess.PIPE,
+                                              stdout=subprocess.PIPE,
+                                              stderr=subprocess.PIPE);
+        self.gitOutput = self.importProcess.stdout
+        self.gitStream = self.importProcess.stdin
+        self.gitError = self.importProcess.stderr
 
-    def run(self, args):
-        self.depotPaths = []
-        self.changeRange = ""
-        self.previousDepotPaths = []
-        self.hasOrigin = False
-
-        # map from branch depot path to parent branch
-        self.knownBranches = {}
-        self.initialParents = {}
+    def closeStreams(self):
+        self.gitStream.close()
+        if self.importProcess.wait() != 0:
+            die("fast-import failed: %s" % self.gitError.read())
+        self.gitOutput.close()
+        self.gitError.close()
 
+    def run(self, args):
         if self.importIntoRemotes:
             self.refPrefix = "refs/remotes/p4/"
         else:
@@ -3497,15 +3566,7 @@ def run(self, args):
                     b = b[len(self.projectName):]
                 self.createdBranches.add(b)
 
-        self.tz = "%+03d%02d" % (- time.timezone / 3600, ((- time.timezone % 3600) / 60))
-
-        self.importProcess = subprocess.Popen(["git", "fast-import"],
-                                              stdin=subprocess.PIPE,
-                                              stdout=subprocess.PIPE,
-                                              stderr=subprocess.PIPE);
-        self.gitOutput = self.importProcess.stdout
-        self.gitStream = self.importProcess.stdin
-        self.gitError = self.importProcess.stderr
+        self.openStreams()
 
         if revision:
             self.importHeadRevision(revision)
@@ -3585,11 +3646,7 @@ def run(self, args):
             missingP4Labels = p4Labels - gitTags
             self.importP4Labels(self.gitStream, missingP4Labels)
 
-        self.gitStream.close()
-        if self.importProcess.wait() != 0:
-            die("fast-import failed: %s" % self.gitError.read())
-        self.gitOutput.close()
-        self.gitError.close()
+        self.closeStreams()
 
         # Cleanup temporary branches created during import
         if self.tempBranches != []:
@@ -3721,6 +3778,89 @@ def run(self, args):
 
         return True
 
+class P4Unshelve(Command):
+    def __init__(self):
+        Command.__init__(self)
+        self.options = []
+        self.origin = "HEAD"
+        self.description = "Unshelve a P4 changelist into a git commit"
+        self.usage = "usage: %prog [options] changelist"
+        self.options += [
+                optparse.make_option("--origin", dest="origin",
+                    help="Use this base revision instead of the default (%s)" % self.origin),
+        ]
+        self.verbose = False
+        self.noCommit = False
+        self.destbranch = "refs/remotes/p4/unshelved"
+
+    def renameBranch(self, branch_name):
+        """ Rename the existing branch to branch_name.N
+        """
+
+        found = True
+        for i in range(0,1000):
+            backup_branch_name = "{0}.{1}".format(branch_name, i)
+            if not gitBranchExists(backup_branch_name):
+                gitUpdateRef(backup_branch_name, branch_name) # copy ref to backup
+                gitDeleteRef(branch_name)
+                found = True
+                print("renamed old unshelve branch to {0}".format(backup_branch_name))
+                break
+
+        if not found:
+            sys.exit("gave up trying to rename existing branch {0}".format(sync.branch))
+
+    def findLastP4Revision(self, starting_point):
+        """ Look back from starting_point for the first commit created by git-p4
+            to find the P4 commit we are based on, and the depot-paths.
+        """
+
+        for parent in (range(65535)):
+            log = extractLogMessageFromGitCommit("{0}^{1}".format(starting_point, parent))
+            settings = extractSettingsGitLog(log)
+            if settings.has_key('change'):
+                return settings
+
+        sys.exit("could not find git-p4 commits in {0}".format(self.origin))
+
+    def run(self, args):
+        if len(args) != 1:
+            return False
+
+        if not gitBranchExists(self.origin):
+            sys.exit("origin branch {0} does not exist".format(self.origin))
+
+        sync = P4Sync()
+        changes = args
+        sync.initialParent = self.origin
+
+        # use the first change in the list to construct the branch to unshelve into
+        change = changes[0]
+
+        # if the target branch already exists, rename it
+        branch_name = "{0}/{1}".format(self.destbranch, change)
+        if gitBranchExists(branch_name):
+            self.renameBranch(branch_name)
+        sync.branch = branch_name
+
+        sync.verbose = self.verbose
+        sync.suppress_meta_comment = True
+
+        settings = self.findLastP4Revision(self.origin)
+        origin_revision = settings['change']
+        sync.depotPaths = settings['depot-paths']
+        sync.branchPrefixes = sync.depotPaths
+
+        sync.openStreams()
+        sync.loadUserMapFromCache()
+        sync.silent = True
+        sync.importChanges(changes, shelved=True, origin_revision=origin_revision)
+        sync.closeStreams()
+
+        print("unshelved changelist {0} into {1}".format(change, branch_name))
+
+        return True
+
 class P4Branches(Command):
     def __init__(self):
         Command.__init__(self)
@@ -3775,7 +3915,8 @@ def printUsage(commands):
     "rebase" : P4Rebase,
     "clone" : P4Clone,
     "rollback" : P4RollBack,
-    "branches" : P4Branches
+    "branches" : P4Branches,
+    "unshelve" : P4Unshelve,
 }