Merge branch 'master' of git://repo.or.cz/git/fastimport

* 'master' of git://repo.or.cz/git/fastimport: (260 commits)
  Avoid src:dst syntax as default bash completion for git push
  Make it possible to specify the HEAD for the internal findUpstreamBranchPoint function.
  Added git-p4 branches command that shows the mapping of perforce depot paths to imported git branches.
  Warn about conflicting p4 branch mappings and use the first one found.
  Fix the branch mapping detection to be independent from the order of the "p4 branches" output.
  git-p4 fails when cloning a p4 depo.
  Fix initial multi-branch import.
  Only use double quotes on Windows
  Fix git-p4 rebase to detect the correct upstream branch instead of unconditionally
  Moved the code from git-p4 submit to figure out the upstream branch point
  git-p4 submit: Fix missing quotes around p4 commands to make them work with spaces in filenames
  Mention remotes/p4/master also in the documentation.
  Provide some information for single branch imports where the commits go
  git-p4: check for existence of repo dir before trying to create
  Write out the options tag in the log message of imports only if we actually have
  Fix support for explicit disabling of syncing with the origin
  Fix depot-paths encoding for multi-path imports (don't split up //depot/path/foo)
  Fix project name guessing
  Fix updating/creating remotes/p4/* heads from origin/p4/*
  Fixed the check to make sure to exclude the HEAD symbolic refs when updating
  ...

contrib/completion/git-completion.bash

@@ -683,7 +683,7 @@ _git_push ()
 			__gitcomp "$(__git_refs "$remote")" "" "${cur#*:}"
 			;;
 		*)
-			__gitcomp "$(__git_refs2)"
+			__gitcomp "$(__git_refs)"
 			;;
 		esac
 		;;

contrib/fast-import/git-p4.bat

@@ -0,0 +1 @@
+@python "%~d0%~p0git-p4" %*

contrib/fast-import/git-p4.txt

@@ -0,0 +1,159 @@
+git-p4 - Perforce <-> Git converter using git-fast-import
+
+Usage
+=====
+
+git-p4 supports two main modes: Importing from Perforce to a Git repository is
+done using "git-p4 sync" or "git-p4 rebase". Submitting changes from Git back
+to Perforce is done using "git-p4 submit".
+
+Importing
+=========
+
+You can simply start with
+
+  git-p4 clone //depot/path/project
+
+or
+
+  git-p4 clone //depot/path/project myproject
+
+This will create an empty git repository in a subdirectory called "project" (or
+"myproject" with the second command), import the head revision from the
+specified perforce path into a git "p4" branch (remotes/p4 actually), create a
+master branch off it and check it out. If you want the entire history (not just
+the head revision) then you can simply append a "@all" to the depot path:
+
+  git-p4 clone //depot/project/main@all myproject
+
+
+
+If you want more control you can also use the git-p4 sync command directly:
+
+  mkdir repo-git
+  cd repo-git
+  git init
+  git-p4 sync //path/in/your/perforce/depot
+
+This will import the current head revision of the specified depot path into a
+"remotes/p4/master" branch of your git repository. You can use the
+--branch=mybranch option to use a different branch.
+
+If you want to import the entire history of a given depot path just use
+
+  git-p4 sync //path/in/depot@all
+
+To achieve optimal compression you may want to run 'git repack -a -d -f' after
+a big import. This may take a while.
+
+Support for Perforce integrations is still work in progress. Don't bother
+trying it unless you want to hack on it :)
+
+Incremental Imports
+===================
+
+After an initial import you can easily synchronize your git repository with
+newer changes from the Perforce depot by just calling
+
+  git-p4 sync
+
+in your git repository. By default the "remotes/p4/master" branch is updated.
+
+It is recommended to run 'git repack -a -d -f' from time to time when using
+incremental imports to optimally combine the individual git packs that each
+incremental import creates through the use of git-fast-import.
+
+
+A useful setup may be that you have a periodically updated git repository
+somewhere that contains a complete import of a Perforce project. That git
+repository can be used to clone the working repository from and one would
+import from Perforce directly after cloning using git-p4. If the connection to
+the Perforce server is slow and the working repository hasn't been synced for a
+while it may be desirable to fetch changes from the origin git repository using
+the efficient git protocol. git-p4 supports this setup by calling "git fetch origin"
+by default if there is an origin branch. You can disable this using
+
+  git config git-p4.syncFromOrigin false
+
+Updating
+========
+
+A common working pattern is to fetch the latest changes from the Perforce depot
+and merge them with local uncommitted changes. The recommended way is to use
+git's rebase mechanism to preserve linear history. git-p4 provides a convenient
+
+  git-p4 rebase
+
+command that calls git-p4 sync followed by git rebase to rebase the current
+working branch.
+
+Submitting
+==========
+
+git-p4 has support for submitting changes from a git repository back to the
+Perforce depot. This requires a Perforce checkout separate to your git
+repository. To submit all changes that are in the current git branch but not in
+the "p4" branch (or "origin" if "p4" doesn't exist) simply call
+
+    git-p4 submit
+
+in your git repository. If you want to submit changes in a specific branch that
+is not your current git branch you can also pass that as an argument:
+
+    git-p4 submit mytopicbranch
+
+You can override the reference branch with the --origin=mysourcebranch option.
+
+If a submit fails you may have to "p4 resolve" and submit manually. You can
+continue importing the remaining changes with
+
+  git-p4 submit --continue
+
+After submitting you should sync your perforce import branch ("p4" or "origin")
+from Perforce using git-p4's sync command.
+
+If you have changes in your working directory that you haven't committed into
+git yet but that you want to commit to Perforce directly ("quick fixes") then
+you do not have to go through the intermediate step of creating a git commit
+first but you can just call
+
+  git-p4 submit --direct
+
+
+Example
+=======
+
+# Clone a repository
+  git-p4 clone //depot/path/project
+# Enter the newly cloned directory
+  cd project
+# Do some work...
+  vi foo.h
+# ... and commit locally to gi
+  git commit foo.h
+# In the meantime somebody submitted changes to the Perforce depot. Rebase your latest
+# changes against the latest changes in Perforce:
+  git-p4 rebase
+# Submit your locally committed changes back to Perforce
+  git-p4 submit
+# ... and synchronize with Perforce
+  git-p4 rebase
+
+
+Implementation Details...
+=========================
+
+* Changesets from Perforce are imported using git fast-import.
+* The import does not require anything from the Perforce client view as it just uses
+  "p4 print //depot/path/file#revision" to get the actual file contents.
+* Every imported changeset has a special [git-p4...] line at the
+  end of the log message that gives information about the corresponding
+  Perforce change number and is also used by git-p4 itself to find out
+  where to continue importing when doing incremental imports.
+  Basically when syncing it extracts the perforce change number of the
+  latest commit in the "p4" branch and uses "p4 changes //depot/path/...@changenum,#head"
+  to find out which changes need to be imported.
+* git-p4 submit uses "git rev-list" to pick the commits between the "p4" branch
+  and the current branch.
+  The commits themselves are applied using git diff/format-patch ... | git apply
+