view README @ 21931:89b809fa6cef stable

dirstate: delay writing out to ensure timestamp of each entries explicitly

Even though "dirstate.write()" is invoked explicitly after "normal"
invocations, timestamp field of entries may be still "unset" in the
"dirstate" file itself , because "pack_dirstate" drops it when it is
equal to the timestamp of "dirstate" file itself.

This can avoid overlooking modification of files, which are updated at
same time in the second. But on the other hand, this may hide timing
critical problems.

For example, incorrect "normal"-ing (or lack of "normallookup"-ing on
the already "normal"-ed entry) is visible only when:

  - the target file is modified in the working directory at T1, and
  - "dirstate" file is written out at T2 (!= T1)

Otherwise, T1 is dropped by "pack_dirstate" in "dirstate.write()"
invocation, and "unset" is stored into "dirstate" file.

It often fails to reproduce problems from incorrect "normal"-ing by
Mercurial testset, because automated actions in the small repository
almost always causes that T1 and T2 are same.

This patch adds the debug feature to delay writing out to ensure
timestamp of each entries explicitly.

This feature is used to make timing critical "dirstate" problems
reproducable in subsequent patches.

Mercurial
=========

Mercurial is a fast, easy to use, distributed revision control tool
for software developers.

Basic install:

 $ make            # see install targets
 $ make install    # do a system-wide install
 $ hg debuginstall # sanity-check setup
 $ hg              # see help

Running without installing:

 $ make local      # build for inplace usage
 $ ./hg --version  # should show the latest version

See http://mercurial.selenic.com/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.