Signed-off-by: NRémy Coutable <remy@rymai.me>

Use Rugged's TagCollection#create instead of gitlab-shell's Repository#add_tag for better performance
Signed-off-by: NRémy Coutable <remy@rymai.me>

This is a combination of 3 commits.

- Update the bare repositories info/attributes if the default branch is updated
- Check the diff attributes of a file before showing a diff
- Update CHANGELOG

- Parameter validation as ISO8601 format

"CHANGELOG", "NEWS", "HISTORY", and "CHANGES" are recognized as Changelog files.

Also adds relevant tests for each of these names.

Resolves #14864.

Fixes #15470.
Signed-off-by: NRémy Coutable <remy@rymai.me>

Signed-off-by: NRémy Coutable <remy@rymai.me>

Issue: https://gitlab.com/gitlab-org/gitlab-ce/issues/12785
Merge Request: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3514

To reproduce:

1. Create a project with some content
2. Rename the project
3. Create a new project with the same name.
4. Boom - 404.

After step 2, the branch and tag counts were not being cleared. This would
cause `repository.has_visible_content?` to erroneously return `true`
for the newly-created project.

Closes #13384

Closes #14963.

Closes #14961

GitHub Pull Requests importer handle with the repository while
importing data, we need to make sure that the cached values are valid.

This will help us to avoid posible merge conflicts when merging
gitlab-ce to gitlab-ee

Closes #14659

Closes #14580

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

This caches the output of Repository#exists? in Redis while making sure
it's flushed properly when creating new repositories, deleting them,
etc.

For the ProjectWiki tests to work I had to make ProjectWiki#create_repo!
public as testing private methods in RSpec is a bit of a pain.

The avatar logic has been moved from Project to Repository as this makes
caching easier. The logic itself in turn has been changed so that the
logo file names are cached in Redis. This cache is flushed upon pushing
a commit but _only_ if:

1. The commit was pushed to the default branch
2. The commit actually changes any of the logo files

If no branch or commit is given the cache is flushed anyway, this
ensures that calling Repository#expire_cache without any arguments still
flushes the avatar cache (e.g. this is used when removing a project).

Fixes gitlab-org/gitlab-ce#14363

This ensures the right caches are flushed when adding a branch via the
UI, instead of only flushing this one random cache.

This ensures Repository#add_tag calls Repository#before_push_tag instead
of just 1 random cache expiration method.

This ensures that Repository#rm_branch calls
before_remove_branch/after_remove_branch instead of just 1 random cache
expiration method.

The methods used for this are Repository#tag_count and
Repository#branch_count which cache their output in Redis as well as
memoizing it in an instance variable. Both methods have a corresponding
methods/hooks to flush the caches at the right time.

This ensures that the emptiness cache (used for Repository#empty? and
Repository#has_visible_content?) is flushed after comitting changes
(using the web editor, API or Git) for new repositories. Once a
repository is no longer empty there's no need to explicitly flush the
cache for Repository#empty?. The cache for
Repository#has_visible_content? in turn is already flushed whenever
needed.

Fixes gitlab-org/gitlab-ce#13387

If path_with_namespace is nil Repository#raw_repository will also return
nil. Apparently code out there creates a Repository instance without a
namespace path. Right.

Setting the "autocrlf" Git option is an overkill since it's rarely
actually needed. More importantly, it has quite the impact on
performance (see gitlab-org/gitlab-ce#13457 for more information).

By setting "autocrlf" when creating or updating files we guarantee the
option is always set properly when we actually need it _without_
introducing overhead for requests that have nothing to do with this
option.

Fixes gitlab-org/gitlab-ce#13457

This ensures the caches for Repository#empty? and
Repository#has_visible_content? are flushed after a repository has been
imported or forked.

Fixes gitlab-org/gitlab-ce#13505