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Differential D5289

context: remove seemingly impossible code branch
ClosedPublic

Authored by martinvonz on Nov 20 2018, 2:08 AM.

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rHG1423ff45c322: context: remove seemingly impossible code branch
Summary

I'm not a Python expert, but I can't think of a way that the following
branch can ever be hit:

    def _changeid(self):
        if r'_changeid' in self.__dict__:
	    return self._changeid

It seems to me that if that condition is true, then this function
would not have been called. The only exception I can think of is if a
reference to the function had been stored beforehand, something like this:

c = fctx.dict['_changeid']
fctx._changeid
c()

But that seems like very unlikely code to exist.

The condition was added in 921b64e1f7b9 (filecontext: use 'is not
None' to check for filelog existence, 2013-05-01) as a "bonus" change
(in addition to what the patch was actually about)

Diff Detail

Repository
rHG Mercurial
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Automatic diff as part of commit; lint not applicable.
Unit
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Event Timeline

martinvonz created this revision.Nov 20 2018, 2:08 AM
Closed by commit rHG1423ff45c322: context: remove seemingly impossible code branch (authored by martinvonz). · Explain WhyNov 20 2018, 7:26 AM
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mmercurial/context.py (4 lines)

Diff 12570

mercurial/context.py

memfilectx: a filecontext that represents files in-memory, memfilectx: a filecontext that represents files in-memory,
""" """
@propertycache @propertycache
def _filelog(self): def _filelog(self):
return self._repo.file(self._path) return self._repo.file(self._path)
@propertycache @propertycache
def _changeid(self): def _changeid(self):
if r'_changeid' in self.__dict__: if r'_changectx' in self.__dict__:
return self._changeid
elif r'_changectx' in self.__dict__:
return self._changectx.rev() return self._changectx.rev()
elif r'_descendantrev' in self.__dict__: elif r'_descendantrev' in self.__dict__:
# this file context was created from a revision with a known # this file context was created from a revision with a known
# descendant, we can (lazily) correct for linkrev aliases # descendant, we can (lazily) correct for linkrev aliases
return self._adjustlinkrev(self._descendantrev) return self._adjustlinkrev(self._descendantrev)
else: else:
return self._filelog.linkrev(self._filerev) return self._filelog.linkrev(self._filerev)