README

convert: detect removal of ".gitmodules" at git source revisions correctly

Before this patch, all operations applied on ".gitmodules" at git
source revisions are treated as modification, even if they are
actually removal of it.

If removal of ".gitmodules" is treated as modification unexpectedly,
"hg convert" is aborted by the exception raised in
"retrievegitmodules()" for ".gitmodules" at the git source revision
removing it, because that revision doesn't have any information of
".gitmodules".

This patch detects removal of ".gitmodules" at git source revisions
correctly.

If ".gitmodules" is removed at the git source revision, this patch
records "hex(nullid)" as the contents hash value for ".hgsub" and
".hgsubstate" at the destination revision.

This patch makes "getfile()" raise IOError also for ".hgstatus" and
".hgsubstate" if the contents hash value is "hex(nullid)", and this
tells removal of ".hgstatus" and ".hgsubstate" at the destination
revision to "localrepository.commitctx()" correctly.

For files other than ".hgstatus" and ".hgsubstate", checking the
contents hash value in "getfile()" may be redundant, because
"catfile()" for them also does so.

But this patch chooses writing it only once at the beginning of
"getfile()", to avoid writing same code twice both for ".hgsub" and
".hgsubstate" separately.

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.