git/refs, branch v2.17.2

Merge branch 'kg/packed-ref-cache-fix'

2018-02-15T22:55:42Z

Avoid mmapping small files while using packed refs (especially ones with zero size, which would cause later munmap() to fail). * kg/packed-ref-cache-fix: packed_ref_cache: don't use mmap() for small files load_contents(): don't try to mmap an empty file packed_ref_iterator_begin(): make optimization more general find_reference_location(): make function safe for empty snapshots create_snapshot(): use `xmemdupz()` rather than a strbuf struct snapshot: store `start` rather than `header_len`

Merge branch 'sg/cocci-move-array'

2018-02-13T21:39:13Z

Code clean-up. * sg/cocci-move-array: Use MOVE_ARRAY

Merge branch 'mr/packed-ref-store-fix'

2018-02-13T21:39:11Z

Crash fix for a corner case where an error codepath tried to unlock what it did not acquire lock on. * mr/packed-ref-store-fix: files_initial_transaction_commit(): only unlock if locked

packed_ref_cache: don't use mmap() for small files

2018-01-24T20:55:26Z

Take a hint from commit ea68b0ce9f8 (hash-object: don't use mmap() for small files, 2010-02-21) and use read() instead of mmap() for small packed-refs files. Signed-off-by: Kim Gybels Signed-off-by: Junio C Hamano Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

load_contents(): don't try to mmap an empty file

2018-01-24T20:55:26Z

We don't actually create zero-length `packed-refs` files, but they are valid and we should handle them correctly. The old code `xmmap()`ed such files, which led to an error when `munmap()` was called. So, if the `packed-refs` file is empty, leave the snapshot at its zero values and return 0 without trying to read or mmap the file. Returning 0 also makes `create_snapshot()` exit early, which avoids the technically undefined comparison `NULL < NULL`. Reported-by: Kim Gybels Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

packed_ref_iterator_begin(): make optimization more general

2018-01-24T20:55:26Z

We can return an empty iterator not only if the `packed-refs` file is missing, but also if it is empty or if there are no references whose names succeed `prefix`. Optimize away those cases as well by moving the call to `find_reference_location()` higher in the function and checking whether the determined start position is the same as `snapshot->eof`. (This is possible now because the previous commit made `find_reference_location()` robust against empty snapshots.) Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

find_reference_location(): make function safe for empty snapshots

2018-01-24T20:55:26Z

This function had two problems if called for an empty snapshot (i.e., `snapshot->start == snapshot->eof == NULL`): * It checked `NULL < NULL`, which is undefined by C (albeit highly unlikely to fail in the real world). * (Assuming the above comparison behaved as expected), it returned NULL when `mustexist` was false, contrary to its docstring. Change the check and fix the docstring. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

create_snapshot(): use `xmemdupz()` rather than a strbuf

2018-01-24T20:55:26Z

It's lighter weight. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

struct snapshot: store `start` rather than `header_len`

2018-01-24T20:55:26Z

Store a pointer to the start of the actual references within the `packed-refs` contents rather than storing the length of the header. This is more convenient for most users of this field. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

Use MOVE_ARRAY

2018-01-22T19:32:51Z

Use the helper macro MOVE_ARRAY to move arrays. This is shorter and safer, as it automatically infers the size of elements. Patch generated by Coccinelle and contrib/coccinelle/array.cocci in Travis CI's static analysis build job. Signed-off-by: SZEDER Gábor Signed-off-by: Junio C Hamano