formatter: remove experimental marker from -T option I think it's good enough to stabilize the feature, at least for the core and non-experimental commands.

grep: rename {line_number} to {lineno} as well (BC)

annotate: rename {line_number} to {lineno} (BC) I think {lineno} looks more like a common template keyword. It isn't called a {line} to avoid conflicts with the element name of {lines} and the {_|splitlines} filter. https://www.mercurial-scm.org/wiki/GenericTemplatingPlan#Dictionary

resolve: rename {status} to {mergestatus} to not shadow change status (BC) This is a part of the name unification. I think it's somewhat useful to provide a combined view of change/merge statuses. https://www.mercurial-scm.org/wiki/GenericTemplatingPlan#Dictionary

py3: whitelist one additional test Differential Revision: https://phab.mercurial-scm.org/D4817

logtoprocess: connect all fds to /dev/null to avoid bad interaction with pager We detected that pager is waiting for log-to-process script to finish, which is annoying when adding a script on commandfinish that does an HTTP push. There seems to be no workaround on the script side and it will make the behavior on Linux/MacOS closer to the Windows behavior. The drawback is that it makes the related tests more flaky as log-to-process outputs are now really asynchronous. If it's considered a BC change, another option would be to add a config option for this new behavior. I personally think that the different behavior between Windows and Linux is confusing and that it's a bug I would be fine with a new config option. Differential Revision: https://phab.mercurial-scm.org/D4816

logtoprocess: add a test to show pager and ltp bad interaction The next changeset will fix the bad interaction between the pager and log-to- process. Add a test first to make the next changeset easier to understand. Differential Revision: https://phab.mercurial-scm.org/D4815

py3: add one more passing test to whitelist caught by buildbot Thanks to Matt Harbison who fixed the remaining failures of this test. Differential Revision: https://phab.mercurial-scm.org/D4814

cleanupnodes: pass multiple predecessors to `createmarkers` directly

obsolete: allow multiple predecessors in createmarkers The logic for this change is similar to the change to `cleanupnodes` that we did earlier. Now that the rebase code is trying to record a fold, we need to actually record it in the markers. The first step is to have the markers creation API able to receive such fold data. To keep things sane, we restrict fold to on successors.

obsolete: preindent code in createmarkers This will help to make the next change clearer.

obsolete: explicitly pass relation items to effectflag computation To track folds, we are about to change the content of `rel`. To simplify this change, we update the `geteffectflag` function beforehand.

rebase: explicitly track collapses as fold A collapse is a large fold. It is now explicitly tracked (at the cleanupnodes API level).

rebase: use tuple as `replacement` keys Now that `cleanupnodes` support tuples as key, we update the rebase code to use them. No changes in the replacement tracked are introduced yet.

rebase: expand a long "one-liner" When a one-liner gets 3 lines longs, it lose its expressivity benefits. We expand it into a simple for loop. This makes future changes of the code in that area clearer.

cleanupnodes: drop special casing around prune markers (API) The `cleanupnodes` has logic to skip the creation of "prune" markers if the changeset is already obsolete. This feels strange and gets in the way of code changes to tracks folds. Now that callers no longer request such prune, we can drop this logic. In many cases, pruning through cleanupnodes should be replaced by internal phase usage.

rebase: don't try to prune obsolete changeset already in the destination With similar motivations to the previous changesets, we stop marking changeset from pruning when it is not the command intention. In this case, we still need to distinguish between the strip and the obsolete case.

histedit: don't cleanup nodes already disposed of If something else took care of these temporary nodes, we don't need to do anything about it. This less liberal usage of pruning through cleanup nodes will help us further cleanup on the road to explicitly tracks folds.

py3: avoid b'' output in test-hgweb-non-interactive.t I couldn't figure out how to get the list to print without b'' with pycompat.write(), without converted each element to str.

py3: convert print to a function call in a few tests I *think* this is the last of them.

py3: use util.forcebytestr() to convert push lock error to bytes

py3: byteify windows.shelltocmdexe() This makes test-doctest.py happy on Windows.

run-tests: flush output stream before prompting to accept changes With py3 on Windows, the prompt to accept changes in an --interactive run wasn't showing up until after the choice was read from stdin.

py3: use util.forcebytestr() to convert error messages to bytes This makes the python 3 buildbot green again. Differential Revision: https://phab.mercurial-scm.org/D4811

context: stop catching TypeError when converting hex nodeid to binary It has been a programming error to pass a 40-character string that is not a hex nodeid since 8b86acc7aa64 (context: drop support for looking up context by ambiguous changeid (API), 2018-04-28), so we can just let it raise a TypeError. Differential Revision: https://phab.mercurial-scm.org/D4807

context: stop catching and re-raising FilteredRepoLookupError FilteredRepoLookupError is only raised by changectx's constructor and the higher-level scmutil.revsymbol(), so there's no need to catch it in changectx's constructor. Differential Revision: https://phab.mercurial-scm.org/D4806

util: use a context manager in readlock()

py3: convert os.readlink() path to native strings on Windows Windows insisted that it needs to be str. I skipped the stuff in the posix module, and left `tests/f` and `run-tests.py` alone for now.

py3: suppress the output from .write() calls in the remaining tests

py3: conditionalize json float precision difference in test-debugcommands.t