Create a branch for the merge, so it's easier to do local testing

without having to constantly revert out of master.

tools/git-mpr.py

@@ -1,115 +1,128 b''
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 """
 Usage:
-    python git-mpr.py -m 1657
+    git-mpr [-h] [-l | -a] [pr-number [pr-number ...]]
+
+Type `git mpr -h` for details.
 """
+
 from __future__ import print_function
 
 import io, os
 import argparse
 from subprocess import check_call, CalledProcessError
 
 import gh_api
 
 ipy_repository = 'git://github.com/ipython/ipython.git'
 gh_project = "ipython/ipython"
 not_merged = {}
 
 def merge_branch(repo, branch ):
     """try to merge the givent branch into the current one
     
     If something does not goes smoothly, merge is aborted
     
     Returns True if merge sucessfull, False otherwise
     """
     # Delete the branch first
     try :
         check_call(['git', 'pull', repo, branch], stdin=io.open(os.devnull))
     except CalledProcessError :
         check_call(['git', 'merge', '--abort'])
         return False
     return True
 
+    
+def git_new_branch(name):
+    """Create a new branch with the given name and check it out.
+    """
+    check_call(['git', 'checkout', '-b', name])
 
+    
 def merge_pr(num):
     """ try to merge the branch of PR `num` into current branch
     """
     # Get Github authorisation first, so that the user is prompted straight away
     # if their login is needed.
     
     pr = gh_api.get_pull_request(gh_project, num)
     repo = pr['head']['repo']['clone_url']
 
 
     branch = pr['head']['ref']
     mergeable = merge_branch(repo=repo, 
                  branch=branch,
               )
     if not mergeable :
         cmd = "git pull "+repo+" "+branch
         not_merged[str(num)] = cmd
         print("==============================================================================")
         print("Something went wrong merging this branch, you can try it manually by runngin :")
         print(cmd)
         print("==============================================================================")
         
     
 def main(*args):
     parser = argparse.ArgumentParser(
             description="""
                 Merge one or more github pull requests by their number. If any
                 one pull request can't be merged as is, its merge is ignored
                 and the process continues with the next ones (if any).
                 """
             )
 
     grp = parser.add_mutually_exclusive_group()
     grp.add_argument(
             '-l',
             '--list',
             action='store_const',
             const=True,
             help='list PR, their number and their mergeability')
     grp.add_argument('-a',
             '--merge-all',
             action='store_const',
             const=True ,
             help='try to merge as many PR as possible, one by one')
     parser.add_argument('merge',
             type=int,
             help="The pull request numbers",
             nargs='*',
             metavar='pr-number')
     args = parser.parse_args()
 
     if(args.list):
         pr_list = gh_api.get_pulls_list(gh_project)
         for pr in pr_list :
             mergeable = gh_api.get_pull_request(gh_project, pr['number'])['mergeable']
 
             ismgb = u"√" if mergeable else " "
             print(u"* #{number} [{ismgb}]:  {title}".format(
                 number=pr['number'],
                 title=pr['title'],
                 ismgb=ismgb))
 
     if(args.merge_all):
+        branch_name = 'merge-' + '-'.join(str(pr['number']) for pr in pr_list)
+        git_new_branch(branch_name)
         pr_list = gh_api.get_pulls_list(gh_project)
         for pr in pr_list :
             merge_pr(pr['number'])
 
 
     elif args.merge:
+        branch_name = 'merge-' + '-'.join(map(str, args.merge))
+        git_new_branch(branch_name)
         for num in args.merge :
             merge_pr(num)
 
     if not_merged :
         print('*************************************************************************************')
         print('the following branch have not been merged automatically, considere doing it by hand :')
         for num, cmd in not_merged.items() :
             print( "PR {num}: {cmd}".format(num=num, cmd=cmd))
         print('*************************************************************************************')
 
 if __name__ == '__main__':
     main()