phabricator: read more metadata from local:commits local:commits metadata can contain branch info, and 'rev' has been superseded by 'commit', see: https://github.com/phacility/arcanist/blob/83661809e532c3fe444a8bf7c7d6936e6377691b/src/repository/api/ArcanistMercurialAPI.php#L281 Differential Revision: https://phab.mercurial-scm.org/D6300

phabricator: don't assume the existence of properties of local:commits Not all the properties are guaranteed to be there, so if we don't check first we could die with a KeyError. Differential Revision: https://phab.mercurial-scm.org/D6299

phabricator: include branch in the diffproperty metadata This does not make Phabricator display the branch in web UI anywhere as that still need us to use creatediff API for that. However a future patch will make phabread use this to include the branch in its `hg import`-able output. Differential Revision: https://phab.mercurial-scm.org/D6297

tests: demonstrate `hg log -r . <file>` linkrev bug Differential Revision: https://phab.mercurial-scm.org/D6309

unionrepo: sync with repository API Differential Revision: https://phab.mercurial-scm.org/D6289

match: remove unused match.__iter__ implementation (API) Differential Revision: https://phab.mercurial-scm.org/D6305

fix: allow fixer tools to return metadata in addition to the file content With this change, fixer tools can be configured to output a JSON object that will be parsed and passed to hooks that can be used to print summaries of what code was formatted or perform other post-fixing work. The motivation for this change is to allow parallel executions of a "meta-formatter" tool to report back statistics, which are then aggregated and processed after all formatting has completed. Providing an extensible mechanism inside fix.py is far simpler, and more portable, than trying to make a tool like this communicate through some other channel. Differential Revision: https://phab.mercurial-scm.org/D6167

context: check file exists before getting data from _wrappedctx overlayworkingctx class is used to do in-memory merging. The data() function of that class has logic to look for data() in the wrappedctx if the file data in cache is empty and if the file is dirty. This assumes that if a file is dirty and cache has empty data for it, it will exists in the _wrappedctx. However this assumption can be False in case when we are merging a file which is empty in destination. In these cases, the backup file 'foo.orig' created by our internal merge algorithms will be empty, however it won't be present in _wrappedctx. This case will lead us to error like the one this patch is fixing. Let's only fallback to getting data from wrappedctx if cache has 'None' as data. Differential Revision: https://phab.mercurial-scm.org/D6308

tests: show IMM is broken when merging file empty in destination When we are doing in-memory merging, and we are merging a file which is empty in merge destination, it leads to error 'abort: xxx not found in manifest'. Next patch will fix this error. Differential Revision: https://phab.mercurial-scm.org/D6307

buildrpm: bump bundled Python version to 2.7.16 when building for centos{5,6} When building rpm packages for centos 5 and 6, we bundle a mercurial-specific version of Python 2.7 in /opt/python-hg. This change is analogous to 5e947367606c, and bumps the embedded Python version from 2.7.14 (released in 2017) to 2.7.16 (latest as of today).

merge with stable

phabricator: set local:commits time metadata as an int, not a string Same as arcanist does Differential Revision: https://phab.mercurial-scm.org/D6296

phabricator: use templatefilters.json in writediffproperties Instead of json.dumps, since it makes the code simpler and more readable. This would have been the better option for 8fd19a7b4ed6 but I wasn't aware of it at the time. Differential Revision: https://phab.mercurial-scm.org/D6295

commands: use byteskwargs() in verify() Otherwise Python 3 complains about the missing key. Differential Revision: https://phab.mercurial-scm.org/D6294

match: use raw strings to avoid illegal baskslash escape Python 3.8 was complaining about the invalid escape sequences. Let's use raw strings to avoid the warning and double baskslashes. Differential Revision: https://phab.mercurial-scm.org/D6293