perf: fix `perfhelper-mergecopies` report of #changesets Same as `perfhelper-pathcopies`. The previous computation `<base>::<target>` was wrong, what we actually need is `::<target> - ::<base>`. This is now fixed.

perf: fix `perfhelper-pathcopies` report of #changesets The previous computation `<base>::<target>` was wrong, what we actually need is `::<target> - ::<base>`. This is now fixed

py3: use integer division in curseschunkselector.printstring() This fixes a crash when scrolling in curses UI when refresh() is called when a float value (namely 'self.firstlineofpadtoprint', taking its value indirectly from 'self.linesprintedtopadsofar').

crecord: drop duplicated set of firstlineofpadtoprint attribute The attribute is already set a couple of lines above, in curseschunkselector.__init__().

patchbomb: use mail.Generator alias for py2/py3 compat

py3: use email.generator.BytesGenerator in patch.split() This fixes test-import.t on python3. We add Generator alias in mail module to handle python2/python3 compatibility.

py3: only flush before prompting during interactive patch filtering Follows up on c9093ae8d6c4. It's enough to flush just before each prompt.

py3: add a missing b'' prefix in test extension for chg Differential Revision: https://phab.mercurial-scm.org/D7038

fuzz: new target to fuzz jsonescapeu8fast This code just feels complicated enough we should go ahead and give it a dedicated fuzzer: we've found bugs in similar things before. Differential Revision: https://phab.mercurial-scm.org/D7034

fuzz: new fuzzer for fncache-related functions Not all of these are strictly fncache-related, but they all have th same signature and similar-enough behavior that we may as well fuzz them together. No obvious bugs for once, but these felt like they were just complicated enough to cover. Differential Revision: https://phab.mercurial-scm.org/D7033

fuzz: exercise a little more revlog code Differential Revision: https://phab.mercurial-scm.org/D7032

fuzz: new fuzzer for dirs.c This found a six-year-old bug immediately, and then I put it through a few CPU-days of time before sending it. Differential Revision: https://phab.mercurial-scm.org/D7031

dirs: fix trivial over-read of input data This code, introduced in 8c0a7eeda06d, was intentionally over-reading an input string to avoid getting a shared string object for a one-byte input. Unfortunately with an empty input (like in the case of a fuzzer getting started) this was a trivial over-read and triggered an AddressSanitizer failure. I went out of my way to make sure the code still does the copy-avoidance tricks. I don't think this change will cost us much performance since the one-character strings should be cached aggressively anyway. Differential Revision: https://phab.mercurial-scm.org/D7030

sidedatacopies: deal with upgrading and downgrading to that format This is quite useful to test this on real life data. Differential Revision: https://phab.mercurial-scm.org/D6955

sidedatacopies: move various copies related function to the copies modules We will need to access these logic form the copies module. So we move them from their higher level module to the lower level `copies` module. We cannot use them from their top level module as it would create cycles. Differential Revision: https://phab.mercurial-scm.org/D6954

sidedatacopies: read rename information from sidedata Repository using the new format now use changeset centric algorithm and read the copies information from the changelog sidedata. Differential Revision: https://phab.mercurial-scm.org/D6953

changelog: make copies related function return None or a valid value With the previous code, existing but empty value were not "decoded", leading to the method returning one of `None`, some valid value (`list` or `dict`) or `b''`. On a general basis, not explicitly checking for None is a source of bugs. Having a clean return types will help the side-data copies code in future changesets. Differential Revision: https://phab.mercurial-scm.org/D7037

test: fix zstd related output in pure tests Differential Revision: https://phab.mercurial-scm.org/D7036

sidedatacopies: get and store sidedata in the changelogrevision object The object provide a simple way to access changelog entry, we need it to also bear the sidedata value. Since the sidedata are retrieved at the same time as the revision, we can do that without extra cost. Differential Revision: https://phab.mercurial-scm.org/D6951

sidedatacopies: write copies information in sidedata when applicable If the format of the repository indicate it stores copies information into changeset's sidedata, then we actually write that information into sidedata at commit time. It will be put to use in later changesets. Currently, we store all field unconditionally, but that is likely to change in the future for the sake of efficiency. Differential Revision: https://phab.mercurial-scm.org/D6950

sidedatacopies: introduce a sidedata testcase for test-copies-in-changeset.t For now it is equivalent to the filelog case, but introducing this early helps make the comings changesets clearer. Differential Revision: https://phab.mercurial-scm.org/D6949

sidedatacopies: introduce a sidedata testcase for test-copies-unrelated.t For now it is equivalent to the filelog case, but introducing this early helps make the comings changesets clearer. Differential Revision: https://phab.mercurial-scm.org/D6948

sidedatacopies: introduce a sidedata testcase for test-copies.t For now it is equivalent to the filelog case, but introducing this early helps make the comings changesets clearer. Differential Revision: https://phab.mercurial-scm.org/D6947

sidedatacopies: teach upgrade about the new requirement The `debugformat` and `debugupgraderepo` command now detect the requirement. (upgrade to and from are not currently possible). Differential Revision: https://phab.mercurial-scm.org/D6946