view i18n/polib.LICENSE @ 29203:731ced087a4b

vfs: make rename avoid ambiguity of file stat if needed

In some cases below, renaming from backup is used to restore original
contents of a file. If renaming keeps ctime, mtime and size of a file,
restoring is overlooked, and old contents cached before restoring
isn't invalidated as expected.

  - failure of transaction before closing (only from '.hg/journal.dirstate')
  - rollback of previous transaction (from '.hg/undo.*')
  - failure in dirstateguard scope (from '.hg/dirstate.SUFFIX')

To avoid such problem, this patch makes vfs.rename() avoid ambiguity
of file stat, if needed.

Ambiguity check is executed, only if:

  - checkambig=True is specified (not all renaming needs ambiguity check), and
  - destination file exists before renaming

This patch is a part of preparation for "Exact Cache Validation Plan":

    https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan

copyright (c) 2006-2010 David JEAN LOUIS

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