contrib/debugshell.py

largefiles: rewrite merge code using dictionary with entry per file

In overridecalculateupdates(), we currently only deal with conflicts
that result in a 'g' action for either the largefile or a standin. We
will soon want to deal cases with 'cd' and 'dc' actions here. It will
be easier to reason about such cases if we rewrite it using a dict
from filename to action.

A side-effect of this change is that the output can only have one
action per file (which should be a good change). Before this change,
when one of the tests in test-issue3084 received this input (the 'a'
in the input was a result of 'cd' conflict resolved in favor of the
modified file):

  'g': [('.hglf/f', ('',), 'remote created')],
  'a': [('f', None, 'prompt keep')],

and the user chose to keep the local largefile, it produced this
output:


  'g': [('.hglf/f', ('',), 'remote created')],
  'r': [('f', None, 'replaced by standin')],
  'a': [('f', None, 'prompt keep')],

Although 'a' actions are processed after 'r' actions by
recordupdates(), it still worked because 'a' actions have no effect on
merges (only on updates). After this change, the output is:

  'g': [('.hglf/f', ('',), 'remote created')],
  'r': [('f', None, 'replaced by standin')],

Similarly, there are several tests in test-largefiles-update that get
inputs like:

  'a': [('.hglf/large2', None, 'prompt keep')],
  'g': [('large2', ('',), 'remote created')],

and when the user chooses to keep the local largefile, they produce
this output:

  'a': [('.hglf/large2', None, 'prompt keep'),
        ('.hglf/large2', None, 'keep standin')],
  'lfmr': [('large2', None, 'forget non-standin largefile')],

In this case, it was not a merge but an update, so the 'a' action does
have an effect. However, since dirstate.add() is idempotent, it still
has no obserable effect.

After this change, the output is:

  'a': [('.hglf/large2', None, 'keep standin')],
  'lfmr': [('large2', None, 'forget non-standin largefile')],

# debugshell extension
"""a python shell with repo, changelog & manifest objects"""

import sys
import mercurial
import code
from mercurial import cmdutil

cmdtable = {}
command = cmdutil.command(cmdtable)

def pdb(ui, repo, msg, **opts):
    objects = {
        'mercurial': mercurial,
        'repo': repo,
        'cl': repo.changelog,
        'mf': repo.manifest,
    }

    code.interact(msg, local=objects)

def ipdb(ui, repo, msg, **opts):
    import IPython

    cl = repo.changelog
    mf = repo.manifest
    cl, mf # use variables to appease pyflakes

    IPython.embed()

@command('debugshell|dbsh', [])
def debugshell(ui, repo, **opts):
    bannermsg = "loaded repo : %s\n" \
                "using source: %s" % (repo.root,
                                      mercurial.__path__[0])

    pdbmap = {
        'pdb'  : 'code',
        'ipdb' : 'IPython'
    }

    debugger = ui.config("ui", "debugger")
    if not debugger:
        debugger = 'pdb'

    # if IPython doesn't exist, fallback to code.interact
    try:
        __import__(pdbmap[debugger])
    except ImportError:
        ui.warn("%s debugger specified but %s module was not found\n"
                % (debugger, pdbmap[debugger]))
        debugger = 'pdb'

    getattr(sys.modules[__name__], debugger)(ui, repo, bannermsg, **opts)