discovery: slowly increase sampling size Some pathological discovery runs can requires many roundtrip. When this happens things can get very slow. To make the algorithm more resilience again such pathological case. We slowly increase the sample size with each roundtrip (+5%). This will have a negligible impact on "normal" discovery with few roundtrips, but a large positive impact of case with many roundtrips. Asking more question per roundtrip helps to reduce the undecided set faster. Instead of reducing the undecided set a linear speed (in the worst case), we reduce it as a guaranteed (small) exponential rate. The data below show this slow ramp up in sample size: round trip | 1 | 5 | 10 | 20 | 50 | 100 | 130 | sample size | 200 | 254 | 321 | 517 | 2 199 | 25 123 | 108 549 | covered nodes | 200 | 1 357 | 2 821 | 7 031 | 42 658 | 524 530 | 2 276 755 | To be a bit more concrete, lets take a very pathological case as an example. We are doing discovery from a copy of Mozilla-try to a more recent version of mozilla-unified. Mozilla-unified heads are unknown to the mozilla-try repo and there are over 1 million "missing" changesets. (the discovery is "local" to avoid network interference) Without this change, the discovery: - last 1858 seconds (31 minutes), - does 1700 round trip, - asking about 340 000 nodes. With this change, the discovery: - last 218 seconds (3 minutes, 38 seconds a -88% improvement), - does 94 round trip (-94%), - asking about 344 211 nodes (+1%). Of course, this is an extreme case (and 3 minutes is still slow). However this give a good example of how this sample size increase act as a safety net catching any bad situations. We could image a steeper increase than 5%. For example 10% would give the following number: round trip | 1 | 5 | 10 | 20 | 50 | 75 | 100 | sample size | 200 | 321 | 514 | 1 326 | 23 060 | 249 812 | 2 706 594 | covered nodes | 200 | 1 541 | 3 690 | 12 671 | 251 871 | 2 746 254 | 29 770 966 | In parallel, it is useful to understand these pathological cases and improve them. However the current change provides a general purpose safety net to smooth the impact of pathological cases. To avoid issue with older http server, the increase in sample size only occurs if the protocol has not limit on command argument size.

tests: make the grep pattern in remotefilelog-gcrepack portable (issue6122) test-remotefilelog-gcrepack was using "\" to escape "|" in the grep pattern. The most of implementations ignore "\" when it is followed by "|", so the regex works. However, OpenBSD doesn't ignore "\" and considers "|" part of the text instead of create two branches. Neither of both behaviors violate POSIX. This change removes the unnecessary escape character and changes grep to egrep, so the extended regular expression works on every unix. This is part of the bug 6122. Tested on OpenBSD, GNU, FreeBSD, NetBSD, Solaris 11 and BusyBox. Credits to Todd C. Miller, Paul de Weerd and Ingo Schwarze for helping me with it.

help: document new "bookmarksinstore" requirement in internals.requirements Differential Revision: https://phab.mercurial-scm.org/D6413

absorb: fix interactive mode I didn't know existed While investigating a bug in `hg absorb -e` I unintentionally discovered `hg absorb --interactive` and its brokenness. This adds a test and restores the functionality. Note that this interface is still marked experimental, so we can change this to be more sophisticated in the future. Differential Revision: https://phab.mercurial-scm.org/D6411

tests: work around libressl being different about error strings (issue6122) As far as I can tell, this is the right behavior. Thanks to Alex Gaynor for checking what the string means by looking at libressl sources for me. Differential Revision: https://phab.mercurial-scm.org/D6410

merge with stable

templatekw: change default value of 'requires' to () Since we dropped support for the old-style template keywords, we no longer have to distinguish None (old-style) and an empty requirement (new-style).