git-branched

gistfile1.py

#!/usr/bin/env python
"""
git-branched - show metadata about where a branch came from (and optionally,
what commits were on the branch)

Based on the method here:
http://stackoverflow.com/a/4991675/75956

Some examples:

    git branched hotfix/2.31.1 master
    git branched --rev-list=1 hotfix/2.31.1 master
    git branched --log=1 hotfix/2.31.1 master
    git branched --log=oneline hotfix/2.31.1 master

written by me
https://github.com/lost-theory
"""

import subprocess, sys, argparse, os

def get_oldest_ancestor(b1, b2):
    """Find the oldest common element between rev-lists b1 and b2."""
    b2 = set(b2)
    last = None
    for c in reversed(b1):
        if c not in b2:
            return last
        last = c
    return None

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='show metadata about where a branch came from (and optionally, what commits were on the branch).')
    parser.add_argument('--rev-list', action='store', default=False, help='Show the rev-list instead of where the branch was cut from.')
    parser.add_argument('--log', action='store', default=False, help='Show the commit log instead of where the branch was cut from.')
    parser.add_argument('branch1', metavar='branch1', nargs=1, help='The branch you are interested in.')
    parser.add_argument('branch2', metavar='branch2', nargs=1, help='The branch it was cut from.')
    args = parser.parse_args(sys.argv[1:])

    p1 = subprocess.Popen("git rev-list --first-parent %s" % args.branch1[0], stdout=subprocess.PIPE, shell=True)
    p2 = subprocess.Popen("git rev-list --first-parent %s" % args.branch2[0], stdout=subprocess.PIPE, shell=True)
    (o1,e1) = p1.communicate()
    (o2,e2) = p2.communicate()
    p1.wait()
    p2.wait()

    b1_ancestors = o1.strip().split('\n')
    b2_ancestors = o2.strip().split('\n')
    oldest_ancestor = get_oldest_ancestor(b1_ancestors, b2_ancestors)
    if not oldest_ancestor:
        print "error: '%s' doesn't seem to be branched from '%s'" % (args.branch1[0], args.branch2[0])
        sys.exit(1)

    if args.rev_list:
        b2_ancestors = set(b2_ancestors)
        for c in b1_ancestors:
            if c not in b2_ancestors:
                print c

    elif args.log:
        pretty = '--format="%h | %ad | %an | %s"'
        if args.log in "oneline,short,medium,full,fuller,email,raw".split(","):
            pretty = "--pretty=%s" % args.log
        os.system("git log %s %s..%s" % (pretty, oldest_ancestor, b1_ancestors[0]))

    else:
        print "'%s' was branched from '%s' at:\t%s" % (args.branch1[0], args.branch2[0], oldest_ancestor)
        os.system("git log -1 %s" % oldest_ancestor)