git/reftable, branch v2.36.2

reftable: make assignments portable to AIX xlc v12.01

2022-03-28T20:58:10Z

Change the assignment syntax introduced in 66c0dabab5e (reftable: make reftable_record a tagged union, 2022-01-20) to be portable to AIX xlc v12.1: avar@gcc111:[/home/avar]xlc -qversion IBM XL C/C++ for AIX, V12.1 (5765-J02, 5725-C72) Version: 12.01.0000.0000 The error emitted before this was e.g.: "reftable/generic.c", line 133.26: 1506-196 (S) Initialization between types "char*" and "struct reftable_ref_record" is not allowed. The syntax in the pre-image is supported by e.g. xlc 13.01 on a newer AIX version: avar@gcc119:[/home/avar]xlc -qversion IBM XL C/C++ for AIX, V13.1.3 (5725-C72, 5765-J07) Version: 13.01.0003.0006 But as we've otherwise supported this compiler let's not break it entirely if it's easy to work around it. Suggested-by: René Scharfe Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano

reftable: rename writer_stats to reftable_writer_stats

2022-02-23T21:36:26Z

This function is part of the reftable API, so it should use the reftable_ prefix Signed-off-by: Han-Wen Nienhuys Signed-off-by: Junio C Hamano

reftable: add test for length of disambiguating prefix

2022-02-23T21:36:26Z

The ID => ref map is trimming object IDs to a disambiguating prefix. Check that we are computing their length correctly. Signed-off-by: Han-Wen Nienhuys Signed-off-by: Junio C Hamano

reftable: ensure that obj_id_len is >= 2 on writing

2022-02-23T21:36:26Z

When writing the same hash many times, we might decide to use a length-1 object ID prefix for the ObjectID => ref table, which is out of spec. Signed-off-by: Han-Wen Nienhuys Signed-off-by: Junio C Hamano

reftable: avoid writing empty keys at the block layer

2022-02-23T21:36:26Z

The public interface (reftable_writer) already ensures that keys are written in strictly increasing order, and an empty key by definition fails this check. However, by also enforcing this at the block layer, it is easier to verify that records (which are written into blocks) never have to consider the possibility of empty keys. Signed-off-by: Han-Wen Nienhuys Signed-off-by: Junio C Hamano

reftable: add a test that verifies that writing empty keys fails

2022-02-23T21:36:26Z

Empty keys can only be written as ref records with empty names. The log record has a logical timestamp in the key, so the key is never empty. Signed-off-by: Han-Wen Nienhuys Signed-off-by: Junio C Hamano

reftable: reject 0 object_id_len

2022-02-23T21:36:26Z

The spec says 2 <= object_id_len <= 31. We are lenient and allow 1, but we forbid 0, so we can be sure that we never read a 0-length key. Signed-off-by: Han-Wen Nienhuys Signed-off-by: Junio C Hamano

Merge branch 'ab/auto-detect-zlib-compress2'

2022-02-16T23:14:30Z

The build procedure has been taught to notice older version of zlib and enable our replacement uncompress2() automatically. * ab/auto-detect-zlib-compress2: compat: auto-detect if zlib has uncompress2()

Merge branch 'hn/reftable-coverity-fixes'

2022-02-16T23:14:28Z

Problems identified by Coverity in the reftable code have been corrected. * hn/reftable-coverity-fixes: reftable: add print functions to the record types reftable: make reftable_record a tagged union reftable: remove outdated file reftable.c reftable: implement record equality generically reftable: make reftable-record.h function signatures const correct reftable: handle null refnames in reftable_ref_record_equal reftable: drop stray printf in readwrite_test reftable: order unittests by complexity reftable: all xxx_free() functions accept NULL arguments reftable: fix resource warning reftable: ignore remove() return value in stack_test.c reftable: check reftable_stack_auto_compact() return value reftable: fix resource leak blocksource.c reftable: fix resource leak in block.c error path reftable: fix OOB stack write in print functions

compat: auto-detect if zlib has uncompress2()

2022-01-26T17:05:55Z

We have a copy of uncompress2() implementation in compat/ so that we can build with an older version of zlib that lack the function, and the build procedure selects if it is used via the NO_UNCOMPRESS2 $(MAKE) variable. This is yet another "annoying" knob the porters need to tweak on platforms that are not common enough to have the default set in the config.mak.uname file. Attempt to instead ask the system header to decide if we need the compatibility implementation. This is a deviation from the way we have been handling the "compatiblity" features so far, and if it can be done cleanly enough, it could work as a model for features that need compatibility definition we discover in the future. With that goal in mind, avoid expedient but ugly hacks, like shoving the code that is conditionally compiled into an unrelated .c file, which may not work in future cases---instead, take an approach that uses a file that is independently compiled and stands on its own. Compile and link compat/zlib-uncompress2.c file unconditionally, but conditionally hide the implementation behind #if/#endif when zlib version is 1.2.9 or newer, and unconditionally archive the resulting object file in the libgit.a to be picked up by the linker. There are a few things to note in the shape of the code base after this change: - We no longer use NO_UNCOMPRESS2 knob; if the system header claims a version that is more cent than the library actually is, this would break, but it is easy to add it back when we find such a system. - The object file compat/zlib-uncompress2.o is always compiled and archived in libgit.a, just like a few other compat/ object files already are. - The inclusion of is done in ; we used to do so from which includes as the first thing it does, so from the *.c codes, there is no practical change. - Until objects in libgit.a that is already used gains a reference to the function, the reftable code will be the only one that wants it, so libgit.a on the linker command line needs to appear once more at the end to satisify the mutual dependency. - Beat found a trick used by OpenSSL to avoid making the conditionally-compiled object truly empty (apparently because they had to deal with compilers that do not want to see an effectively empty input file). Our compat/zlib-uncompress2.c file borrows the same trick for portabilty. Signed-off-by: Ævar Arnfjörð Bjarmason Helped-by: Beat Bolli Signed-off-by: Junio C Hamano