delta/git.git/refs, branch ep/commit-static-buf-cleanup

Merge branch 'jk/ref-symlink-loop'

2016-10-17T20:25:20+00:00

A stray symbolic link in $GIT_DIR/refs/ directory could make name
resolution loop forever, which has been corrected.

* jk/ref-symlink-loop:
  files_read_raw_ref: prevent infinite retry loops in general
  files_read_raw_ref: avoid infinite loop on broken symlinks

files_read_raw_ref: prevent infinite retry loops in general

2016-10-10T17:53:33+00:00

Limit the number of retries to 3. That should be adequate to
prevent any races, while preventing the possibility of
infinite loops if the logic fails to handle any other
possible error modes correctly.

After the fix in the previous commit, there's no known way
to trigger an infinite loop, but I did manually verify that
this fixes the test in that commit even when the code change
is not applied.

Signed-off-by: Jeff King 
Reviewed-by: Michael Haggerty 
Signed-off-by: Junio C Hamano

files_read_raw_ref: avoid infinite loop on broken symlinks

2016-10-10T17:53:16+00:00

Our ref resolution first runs lstat() on any path we try to
look up, because we want to treat symlinks specially (by
resolving them manually and considering them symrefs). But
if the results of `readlink` do _not_ look like a ref, we
fall through to treating it like a normal file, and just
read the contents of the linked path.

Since fcb7c76 (resolve_ref_unsafe(): close race condition
reading loose refs, 2013-06-19), that "normal file" code
path will stat() the file and if we see ENOENT, will jump
back to the lstat(), thinking we've seen inconsistent
results between the two calls. But for a symbolic ref, this
isn't a race: the lstat() found the symlink, and the stat()
is looking at the path it points to. We end up in an
infinite loop calling lstat() and stat().

We can fix this by avoiding the retry-on-inconsistent jump
when we know that we found a symlink. While we're at it,
let's add a comment explaining why the symlink case gets to
this code in the first place; without that, it is not
obvious that the correct solution isn't to avoid the stat()
code path entirely.

Signed-off-by: Jeff King 
Reviewed-by: Michael Haggerty 
Signed-off-by: Junio C Hamano

use QSORT

2016-09-29T22:42:18+00:00

Apply the semantic patch contrib/coccinelle/qsort.cocci to the code
base, replacing calls of qsort(3) with QSORT.  The resulting code is
shorter and supports empty arrays with NULL pointers.

Signed-off-by: Rene Scharfe 
Signed-off-by: Junio C Hamano

Merge branch 'mh/ref-store'

2016-09-19T20:47:19+00:00

The ref-store abstraction was introduced to the refs API so that we
can plug in different backends to store references.

* mh/ref-store: (38 commits)
  refs: implement iteration over only per-worktree refs
  refs: make lock generic
  refs: add method to rename refs
  refs: add methods to init refs db
  refs: make delete_refs() virtual
  refs: add method for initial ref transaction commit
  refs: add methods for reflog
  refs: add method iterator_begin
  files_ref_iterator_begin(): take a ref_store argument
  split_symref_update(): add a files_ref_store argument
  lock_ref_sha1_basic(): add a files_ref_store argument
  lock_ref_for_update(): add a files_ref_store argument
  commit_ref_update(): add a files_ref_store argument
  lock_raw_ref(): add a files_ref_store argument
  repack_without_refs(): add a files_ref_store argument
  refs: make peel_ref() virtual
  refs: make create_symref() virtual
  refs: make pack_refs() virtual
  refs: make verify_refname_available() virtual
  refs: make read_raw_ref() virtual
  ...

refs: implement iteration over only per-worktree refs

2016-09-09T22:28:14+00:00

Alternate refs backends might still use files to store per-worktree
refs. So provide a way to iterate over only the per-worktree references
in a ref_store. The other backend can set up a files ref_store and
iterate using the new DO_FOR_EACH_PER_WORKTREE_ONLY flag when iterating.

Signed-off-by: David Turner 
Signed-off-by: Junio C Hamano 
Signed-off-by: Michael Haggerty 
Signed-off-by: Junio C Hamano

refs: make lock generic

2016-09-09T22:28:14+00:00

Instead of including a files-backend-specific struct ref_lock, change
the generic ref_update struct to include a void pointer that backends
can use for their own arbitrary data.

Signed-off-by: David Turner 
Signed-off-by: Junio C Hamano 
Signed-off-by: Michael Haggerty 
Signed-off-by: Junio C Hamano

refs: add method to rename refs

2016-09-09T22:28:14+00:00

This removes the last caller of function get_files_ref_store(), so
remove it.

Signed-off-by: David Turner 
Signed-off-by: Junio C Hamano 
Signed-off-by: Michael Haggerty 
Signed-off-by: Junio C Hamano

refs: add methods to init refs db

2016-09-09T22:28:14+00:00

Alternate refs backends might not need the refs/heads directory and so
on, so we make ref db initialization part of the backend.

Signed-off-by: David Turner 
Signed-off-by: Junio C Hamano 
Signed-off-by: Michael Haggerty 
Signed-off-by: Junio C Hamano

refs: make delete_refs() virtual

2016-09-09T22:28:14+00:00

In the file-based backend, delete_refs has some special optimization
to deal with packed refs.  In other backends, we might be able to make
ref deletion faster by putting all deletions into a single
transaction.  So we need a special backend function for this.

Signed-off-by: David Turner 
Signed-off-by: Junio C Hamano 
Signed-off-by: Michael Haggerty 
Signed-off-by: Junio C Hamano