When there's no matching index entry (for whatever reason), don't
try to dereference the null return value to get at the id.
Otherwise when we break something in the index API, the checkout
test crashes for confusing reasons and causes us to step through
it in a debugger thinking that we had broken much more than we
actually did.
Given a variety of combinations of core.autocrlf settings and
attributes settings, test that we check out data into the working
directory the same as a known-good test resource created by git.git.
These tests want to test that we don't recalculate entries which match
the index already. This is however something we force when truncating
racily-clean entries.
Tick the index forward as we know that we don't perform the
modifications which the racily-clean code is trying to avoid.
In order to avoid racy-git, we zero out the file size for entries with
the same timestamp as the index (or during the initial checkout). This
is the case in a couple of crlf tests, as the code is fast enough to do
everything in the same second.
As we know that we do not perform the modification just after writing
out the index, which is what this is designed to work around, tick the
mtime of the index file such that it doesn't agree with the files
anymore, and we do not zero out these entries.
We want to use the "checkout: moving from ..." message in order to let
git know when a change of branch has happened. Make the convenience
functions for this goal write this message.
The signature for the reflog is not something which changes
dynamically. Almost all uses will be NULL, since we want for the
repository's default identity to be used, making it noise.
In order to allow for changing the identity, we instead provide
git_repository_set_ident() and git_repository_ident() which allow a user
to override the choice of signature.
Git for Windows 1.9.4 changed the behavior when the text=auto
attribute is specified and core.autocrlf=false. Previous observed
behavior would *not* filter files when going into the working
directory, the new behavior *does* filter. Update our behavior to match.
When checking out files, we're performing conversion into the user's
native line endings, but we only want to do it for files which have
consistent line endings. Refuse to perform the conversion for mixed-EOL
files.
The CRLF->LF filter is left as-is, as that conversion is considered to be
normalization by git and should force a conversion of the line endings.
