tech


github forking

2011-09-09 16:25:23 -0700

I don't think GitHub's default workflow for forking a repo is ideal for my needs. Most of the time when I fork a repo, my aim is to fix something or add a small new feature which I will eventually submit upstream as a pull request. While I am hacking away or living with my modifications for a while before I submit them, I want to continue to be able to easily pull in upstream changes as well. So whenever I fork a repo, I want the following:

  • The master branch will track the pristine upstream master. Whenever I have no changes of my own pending, I can just switch my work tree to use master to keep up with the latest changes with a simple git pull.
  • A volatile hack branch where I work on my changes. This is volatile since I'll regularly be rebasing onto the head of master.
  • A volatile pullme branch where I will put changes that are ready for a pull request submission. I may want to continue to hack away in hack while I'm waiting for the resolution of my pull request, so this is analogous to a release branch. But this is volatile since, for the sake of simplicity, I'll be resetting it whenever I'm ready to submit a new pull request.

(By volatile, I mean that I can feel free to rewrite the history on these branches without repercussions.)

So here's how I go about forking a GitHub repo:

git clone <upstream_repo>         # e.g. http://github.com/mxcl/homebrew.git
cd <upstream_repo_name>           # e.g. homebrew
git remote add fork <forked_repo> # e.g. git@github.com:SethMilliken/homebrew.git
git config branch.hack.remote fork
git config branch.hack.merge refs/heads/hack
git branch --no-track hack origin/master
git push fork hack:refs/heads/hack
git checkout hack

At this point here's how things look branches-wise:

$ git branch -r
* hack
  master
  remotes/fork/hack
  remotes/fork/master
  remotes/origin/HEAD -> origin/master
  remotes/origin/master

remotes/fork/master is what the GitHub website uses for it's default branch. I like to clean this up to remove any chance of ambiguity about the name master. To me, master always means the authoritative branch from the canonical repository, never a branch in my fork. Here is how I tidy this up:

  1. Click the Admin button on the forked repo's GitHub page.
  2. Change the Default Branch to "hack".
  3. Delete the forked repo's master with git push fork :master.

If there were a way to name the default branch when you first fork, or to subsequently rename it via a commandline git command, that would simplify things a bit.

To rebase my changes onto incoming upstream, which I do periodically as I'm hacking, and again immediately before submitting a pull request:

git pull --rebase origin master

When I'm finally ready to submit a pull request, here is what I do:

git branch -f pullme hack
git push fork pullme:refs/heads/pullme

This essentially replaces the pullme branch with the current state of the hack branch.

And after my pull request is accepted, I switch back to master.

git checkout master


hg stash

2011-02-28 21:34:32 -0800

I have become accustomed in Git to using git stash to temporarily set aside in-progress changes in my working directory before pulling from upstream. Whenever I use Mercurial now, I find myself wanting analogous functionality. The Googles don't seem to turn up any decent techniques for this, so I have repeatedly reinvented a series incantations to abuse Mercurial's mq extension to provide it. Yet I always manage to forget whatever trick I used by the time I want to do it again. I finally decided to fix it for good, giving myself hg stash and hg pop, allowing a workflow in a dirty working copy that goes something like:

hg stash
hg fetch
hg pop

Here are the relevant .hgrc lines:

[alias]
stash = !hg qinit &>2 /dev/null; hg qqueue --create stash-temp && hg qnew stash && hg qfinish tip && hg strip tip && hg qqueue patches && hg qqueue --purge stash-temp
pop = !hg -R .hg/strip-backup/`ls -rt .hg/strip-backup/ | tail -1` diff -r tip | patch -p 1 -R

Breaking it down:

# hg stash
hg qinit &>2 /dev/null              # initialize mqueue in this directory
                                    # ignore error output since this has likely already been done
                                    # (this could be potentially be problematic if there is some other problem)
hg qqueue --create stash-temp       # create a new patch queue so we don't mess with any existing ones
hg qnew stash                       # create the 'stash' patch with the outstanding modifications
hg qfinish tip                      # apply the patch
hg strip tip                        # now strip it (for the side-effect of the backup bundle)
hg qqueue patches                   # switch back to original patch queue
hg qqueue --purge stash-temp        # delete the temporary patch queue
# hg pop
hg -R .hg/strip-backup/`ls -rt .hg/strip-backup/ | tail -1`     # use the strip bundle as the repository
                                                                # finding it with some shell tricks
                                                                # (likely a better, more portable way to do this)
diff -r tip                                                     # output it as a diff
patch -p 1 -R                                                   # apply that output as a patch
                                                                # and reverse patch since we spun things around
                                                                # with the bundle

Your working copy's .hg/strip-backup/ directory could start to fill up if you use this a lot, so you may want to clean it out occasionally. I decided to not have hg pop automatically cleanup the bundle just in case something goes wrong.

And why not just hg diff > stash.diff && hg revert --all to stash and patch -p 1 < stash.diff to pop? That doesn't really handle binaries, and somehow it feels a little too dangerous to me. But, yeah, for the majority of cases that would probably be sufficient. So I'll leave that here, too:

[alias]
stash = !hg diff > stash.diff && hg revert --all
pop = !patch -p 1


Pentadacytl (or Vimperator) Form Field Editing

2010-03-16 20:05:32 -0700

I have been using Firefox as my primary browser for quite a while now. What held me back from switching initially were two things: 1) unacceptably poor non-native widgets, which have since improved dramatically and 2) no support for the Mac OS X Keychain, which is now available via the Keychain Services Integration extension. But eventually my desire for vim keybindings everywhere pushed me to switch despite these shortcomings. The vimperator pentadactyl Firefox extension allows for entirely keyboard-based browsing, using bindings similar to vim. And even better, it facilitates form field editing using vim via external editor support. So when I want to edit a form field, I type either "gi" (to enter the field) or "f#" (where # is the QuickHint mode number associated with the field; useful if there are multiple fields on the page) then hit Control-i. This creates a new tab with a buffer for that field in an existing instance of MacVim which is always running in the same Space as my browser, so it comes up almost instantaneously. I edit the contents of this buffer using all the goodness of native vim and then type ZZ. Thanks to a couple of autocommands in my .vimrc, this saves the buffer, saves a copy of its contents in a timestamped archive file, closes the buffer, and then hides MacVim, leaving Firefox active with the text I just wrote inserted in the form field, ready to submit.

Here are the requisite pieces of the puzzle:

.pentadactylrc

This is the pentadactyl configuration file. You need to add a line to set your external editor to the script that opens MacVim.

set editor="~/bin/firefox"

shell

Make a symbolic link to your mvim script so that the script can detect the context it should run in.

ln -s ~/bin/mvim ~/bin/firefox

mvim

This is the mvim script that comes bundled with MacVim, moved to ~/bin and modified. Add this bit to the 'case "$name" in' statement:

    *firefox)
        opts="$opts --remote-tab-wait-silent"
        gui=true
        ;;

.vimrc

Next, a couple of additions to the vim configuration file to make ZZ save the contents to an archive, close the buffer, and return Firefox to the foreground.

augroup VimperatorYPentadactyl
    au! BufRead vimperator-*,pentadactyl-* nnoremap <buffer> ZZ :call FormFieldArchive() \| :silent write \| :bd \| :macaction hide:<CR>
    au BufRead vimperator-*,pentadactyl-* imap <buffer> ZZ <Esc>ZZ
augroup END

Finally, here is the function that saves a copy of the form field contents to an archive file, complete with timestamp and url:

function! FormFieldArchive()
    let l:contents = getbufline("%", 1, "$")
    let l:filepath = expand("%")
    let l:filename = expand("%:t:r")
    let l:formfielddir = $HOME . "/webforms/"
    let l:currentdate = TimestampText('date')
    let l:entry = l:formfielddir . l:currentdate . ".txt"
    let l:entryexists = filereadable(l:entry)
    exec "split " . l:entry
    if l:entryexists
        normal Go
        normal o
        exec "call setline(\".\", \"" . TimestampText('time') . "\")"
    else
        exec "call setline(\".\", \"" . TimestampText('journal') . "\")"
        exec "silent !svn add " . l:entry
    endif
    normal o
    exec "call setline(\".\", \"" . l:filename . "\")"
    normal o
    exec "call setline(\".\", " . string(l:contents) . ")"
    write
    bd
endfunction

function! TimestampText(style)
    let l:iswindows = has("win16") || has("win32") || has("win64")
    if l:iswindows
        if a:style == "long"
            let l:dateformat = strftime("%#x %H:%M:%S ")
        elseif a:style == "short"
            let l:dateformat = strftime("%Y-%m-%d %H:%M:%S ")
        endif
        let l:dateformat .= substitute(strftime("%#z"), '[a-z]\+\($\| \)', '', 'g')
    else
        if a:style == "long"
            let l:dateformat = strftime("%Y %b %d %a %X %Z")
        elseif a:style == "journal"
            let l:dateformat = strftime("%A, %B %d, %Y %H:%M:%S %Z")
        elseif a:style == "short"
            let l:dateformat = strftime("%Y-%m-%d %H:%M:%S %Z")
        elseif a:style == "time"
            let l:dateformat = strftime("%H:%M:%S %Z")
        endif
    endif
    if a:style == "date"
        let l:dateformat = strftime("%Y-%m-%d")
    endif
    return l:dateformat
endfunction

This will create a new file with the current date, e.g. "2010-03-15.txt", if it doesn't already exist. If it does exist, it will add the entry to the end of the file separated by a timestamp. TimestampText() is just a convenience function I wrote that returns a timestamp in various strftime() formats.

[2011-02-28 22:10:12 PST Update: Now using pentadactyl, so updated references appropriately. Added TimestampText() function for completeness. A couple of other minor edits and links added.]


snip snip

2004-10-20 00:38:22 -0700

During a dream last night I devised a technique to cut and paste between dreams and reality. I cleverly pasted the description of this technique on the shared dream/reality clipboard. I was thwarted by the fact that alarm clock snooze bars clear the clipboard.


first post from netnewswire

2003-06-01 00:03:24 -0700

NetNewsWire now supports Moveable Type. This is a test of that functionality. If it works well, maybe I'll post more. On a completely unrelated note, I've been experimenting with leaving Sticky Keys turned on to see if I can improve the state of my wrists which have both taken a turn for the worse due to various combinations of foosball, swing dancing, playing guitar, and typing.


ssh tunneling rocks

2003-03-30 00:37:31 -0800

ssh tunneling is a great lightweight vpn stand-in. You do need three things: an account on a externally accessible machine that is on the same internal network as the machine you're tunneling to, the IP address of the machine you're tunneling, and knowledge of what port(s) you need to forward. The syntax is: ssh <your account>@<externally accessible machine> -L <local port>:<internal target host>:<port to forward>