phabricator: use .arcconfig for the callsign if not set locally (issue6243) This makes things easier for people working with more than one repository because this file can be committed to each repository. The bug report asks to read <repo>/.arcrc, but AFAICT, that file lives in ~/ and holds the credentials. And we already track an .arcconfig file. Any callsign set globally is still used if that is all that is present, but .arcconfig will override it if available. The idea behind letting the local hgrc override .arcconfig is that the developer may need to do testing against another server, and not dirty the working directory. Originally I was going to just try to read the callsign in `getrepophid()` if it wasn't present in the hg config. That works fine, but I think it also makes sense to read the URL from this file too. That would have worked less well because `readurltoken()` doesn't have access to the repo object to know where to find the file. Supplimenting the config mechanism is less magical because it reports the source and value of the properties used, and it doesn't need to read the file twice. Invalid hgrc files generally cause the program to abort. I only flagged it as a warning here because it's not our config file, not crucial to the whole program operating, and really shouldn't be corrupt in the typical case where it is checked into the repo. Differential Revision: https://phab.mercurial-scm.org/D7934

config: add a function to insert non-file based, but overridable settings This will be used in the next patch. Until relatively recently (473510bf0575), there was no official way for extensions to inject per-repo config data, so it probably makes sense that `ui.setconfig()` items are sticky, and not affected by loading more config files. But that makes it cumbersome if the extension wants to allow the data it might add to be overridden by any data in the local hgrc file. The only thing I could get to work was to load the local hgrc first, and then check if the source for the config item that should be overridden was *not* the local hgrc file name. But that's brittle because in addition to the file name, the source contains the line number, there are the usual '\' vs '/' platform differences, etc. Differential Revision: https://phab.mercurial-scm.org/D7933

tests: restore phabricator tests and regenerate the recordings These contain the new API chatter. Most of the changes are because some new commits were created, but they're pretty obviously equivalent. I have no idea why the last recording contains real data, whereas it previously looked fake. Differential Revision: https://phab.mercurial-scm.org/D7920

hgrc: introduce HGRCSKIPREPO to skip reading the repository's hgrc We had a way to change the behavior regarding reading the global and user config, but we had nothing regarding the repository hgrc itself. This option is useful in situation where scripts need to be able to work around strange configuration set by the user in his repository. (and were HGPLAIN is not enough). Differential Revision: https://phab.mercurial-scm.org/D7807

debugcommands: move away from line buffered output on binary stream Line buffering on binary file objects is apparently undefined behavior in Python and emits a RuntimeWarning on Python 3.8. See https://bugs.python.org/issue32236. This commit changes the I/O logging file descriptor from line buffered to unbuffered to work around this. I'm no fan of unbuffered I/O for performance reasons. But I don't think it is an issue here given the nature of the code. With this change, test-ssh-proto.t now passes on Python 3.8. Differential Revision: https://phab.mercurial-scm.org/D7948

py3: conditionalize test-lfs-serve-access.t for Python 3.8 This is another case where Python 3.8's traceback printing varies subtly from older Python versions. Again, I'm not sure why. But this is apparently the new behavior. With this change, test-lfs-serve-access.t now passes on Python 3.8! Differential Revision: https://phab.mercurial-scm.org/D7947

py3: add extra traceback line present on Python 3.8 I'm not sure why Python 3.8 is outputting this line. It appears to be a change in behavior of formatting tracebacks on Python 3.8. So let's add it to expected output. With this change, test-hook.t now passes on Python 3.8. Differential Revision: https://phab.mercurial-scm.org/D7946

py3: conditionalize test-flagprocessor.t on Python 3.8 For reasons I don't understand, Python 3.8 is outputting a different lint in the traceback than prior Pythons. The lines in question are: flagutil.addflagprocessor( REVIDX_NOOP, (noopdonothingread, noopdonothing, validatehash,) ) Python <3.8 prints the 2nd line but 3.8 the first line. Perhaps Python changed its traceback logic to always print the first line of a multiple line expression? Whatever the case, with this change, the test now passes on Python 3.8. Differential Revision: https://phab.mercurial-scm.org/D7945