tests: demonstrate a case where a corrupt tag cache causes an abort I happened to hit this trying to cover other cases around valid vs missing entries. I have no idea if this is something that could occur more naturally (similar to how a missing file node in `hgtagsfnodes1` can occur after a strip). There is a test just above this added in f5a7cf0adb12 mentioning it "overwrites the junk", though that tests truncation instead of actual garbage. But since this is just a cache, it probably shouldn't abort with a cryptic message like this. The two options I see both have downsides- either rebuild the cache (and potentially take a long time), or hint to the user to run a debug command. Differential Revision: https://phab.mercurial-scm.org/D9812

debugcommands: prevent using `is False` I was touching this code in a future patch and marmoute warned about usage of `is False` here. Quoting marmoute: ``` "is False" is going to check if the object you have the very same object in memory than the one Python allocated for False (in practice 0) This will "mostly work" on cpython because of implementation details, but is semantically wrong and can start breaking unexpectedly ``` Differential Revision: https://phab.mercurial-scm.org/D10014

hgtagsfnodes: refactor code to compute fnode into separate fn I plan to use this code at one more place while fixing a bug caused by an invalid fnode present in cache. Differential Revision: https://phab.mercurial-scm.org/D10013

error: remove shortening of node in error message This strips the complete 20 bytes node which was not found. Having the the full node in error message is important as it makes debugging easier. If a short node is to be displayed, that should be done by callers. Differential Revision: https://phab.mercurial-scm.org/D9994

copies: filter out copies grafted from another branch Consider this simple history: ``` @ 3 modify y | o 2 copy x to y, modify x | | o 1 copy x to y, modify x |/ o 0 add x ``` If we now rebase commit 3 onto 1, Mercurial will look for copies between commit 2 and commit 1. It does that by going backwards from 2 to 0 and then forwards from 0 to 1. It will find that x was copied to y, since that was what happened on the path between them (namely in commit 1). That leads Mercurial to do a 3-way merge between y@3 and y@1 with x@2 as base. We want to use y@2 as base instead. That's also what happened until commit 1d6d1a15. This patch fixes the regression by adding another filtering step when chaining copies via a diffbase. The new filtering step removes copies that were the same between the two branches (same source and destination, but not necessarily the same contents). Differential Revision: https://phab.mercurial-scm.org/D10120

copies: inline _backwardrenames() in pathcopies() I'll add another filtering step in `patchcopies()` next. I need access to the forward copies for that. Differential Revision: https://phab.mercurial-scm.org/D10119

copies: extract function _backwardcopies() for reversing renames I'll add another callers in the next patch. Differential Revision: https://phab.mercurial-scm.org/D10118

tests: demonstrate how grafted copies are counted when tracing across branches This test demonstrates a regression from 1d6d1a15. Differential Revision: https://phab.mercurial-scm.org/D10117

typing: add some type annotations to mercurial/pathutil.py Differential Revision: https://phab.mercurial-scm.org/D10128

typing: add some type annotations to mercurial/util.py Differential Revision: https://phab.mercurial-scm.org/D10127

typing: add some type annotations to mercurial/phases.py Some of these were helpful in typing other modules, and then I typed the easy-ish ones. Black forces the long `Phasedefaults` definition to be wrapped, which pytype seems OK with (as shown with `reveal_type()`), but it does seem to confuse PyCharm a bit. Differential Revision: https://phab.mercurial-scm.org/D10126

typing: add type annotations to the public methods of mercurial/subrepoutil.py Differential Revision: https://phab.mercurial-scm.org/D10125

typing: add type annotations to mercurial/i18n.py I'm a little unsure of this because `gettext()` clearly allows for passing unicode. But the comments seem to indicate that this is related to tests, and this was useful for catching unicode being passed to `_()` in the keyring extension. I'm also not sure why `_(None)` would make any sense, so maybe the argument shouldn't be optional? I didn't add it to the lambda in plain mode because that spilled beyond 80 characters and so black mangled it. Black and pytype disagree on where the comment to disable a check needs to go, so this has to disable and then enable the checking. Differential Revision: https://phab.mercurial-scm.org/D10124

typing: add type annotations to mercurial/utils/dateutil.py For now, I'm just typing around the edges to help find issues with TortoiseHg. If the custom `hgdate` type is useful elsewhere as I go, I'll move it to a file dedicated to custom types. I'm not loving the ban on camelcase type names here that test-check-code.t flagged, but I'm not sure how to disable that even if everyone agreed that it's a bad idea to go against the normal convention for types. While here, fix an issue that pytype found in `parsedate` when an invalid date tuple is passed by raising a ProgrammingError instead of crashing. (Tuple doesn't have a `strip` attribute.) Differential Revision: https://phab.mercurial-scm.org/D10123

shelve: fix conversion of exceptions to strings flagged by pytype I've seen this done several ways and don't know what's correct. But pytype was unhappy about the previous way: FAILED: /mnt/c/Users/Matt/hg/tests/.pytype/pyi/mercurial/shelve.pyi /usr/bin/python3.6 -m pytype.single --imports_info /mnt/c/Users/Matt/hg/tests/.pytype/imports/mercurial.shelve.imports --module-name mercurial.shelve -V 3.6 -o /mnt/c/Users/Matt/hg/tests/.pytype/pyi/mercurial/shelve.pyi --analyze-annotated --nofail --quick /mnt/c/Users/Matt/hg/mercurial/shelve.py File "/mnt/c/Users/Matt/hg/mercurial/shelve.py", line 244, in _verifyandtransform: Function bytestr.__init__ was called with the wrong arguments [wrong-arg-types] Expected: (self, ints: Iterable[int]) Actually passed: (self, ints: Union[KeyError, TypeError, ValueError]) File "/mnt/c/Users/Matt/hg/mercurial/shelve.py", line 253, in _getversion: Function bytestr.__init__ was called with the wrong arguments [wrong-arg-types] Expected: (self, ints: Iterable[int]) Actually passed: (self, ints: ValueError) The following methods aren't implemented on ValueError: __iter__ Differential Revision: https://phab.mercurial-scm.org/D10122