copies: simplify the conditional for _filter's case 3 The conditional is much simpler and the test are actually happier. This clarification of the conditional will also be necessary to properly support tracing more renames in a coming changeset. Differential Revision: https://phab.mercurial-scm.org/D9795

copies: clarify which case some conditional are handling This make the function a bit clearer. The middle conditional get no label because we about about to remove it. See next changeset for details. Differential Revision: https://phab.mercurial-scm.org/D9794

copies: explicitly filter out existing file in graftcopies The `graftcopies` function does something very strange (maybe even wrong), it calls `_filter` with a pair of changeset that does not match the one used to compute the copies informations. We are about to do some rework of `_filter` to make it closer to its documented intent and fix a couple of bug. This means some of the logic that only make sense for graft need to go somewhere else. We add the extra filtering with proper documentation to `graftcopies`. Differential Revision: https://phab.mercurial-scm.org/D9802

histedit: rip out mysterious catch-all ignore curses.error handler I have no idea why this was here, and ripping it out doesn't obviously break anything for me (tests all pass, I can poke around chistedit UI a bit without issue), so I'm thinking we should rip it out and see if we get bug reports. Differential Revision: https://phab.mercurial-scm.org/D9855

histedit: notice when the main window underflows height and abort If you try to have a 13-line-tall terminal and use curses histedit, it fails by spinning in an infinite loop due to the catch-all ignore of curses errors on line 1682 of histedit.py. We should also fix that catch-all ignore of curses errors (what other demons lurk here, I wonder?) but we can trivially catch this case and guide the user to a happy path. We've seen this mostly in IDE users that have a tendency to have really tiny embedded terminal windows. Differential Revision: https://phab.mercurial-scm.org/D9854

histedit: don't assign to _ for unused values I don't know what this ignored value is, but we need to not clobber the _() function from gettext, or we get mysterious crashes instead of internationalizing some strings in my upcoming patches. Differential Revision: https://phab.mercurial-scm.org/D9853

hghave: list the module needed for the `vcr` check I'm tired of having to look up modules each time I setup a system, and try to distinguish between similar package names to get the right one. Now that the search API has been disabled, it's even harder. There are other python packages here that should be listed like this, but this is the one that came up missing today, so it's a start. Differential Revision: https://phab.mercurial-scm.org/D9879

debugshell: add a simple command for starting an interactive shell This simplifies interactive exploration of the Mercurial APIs. The ui and repo instances are provided as local variables. Differential Revision: https://phab.mercurial-scm.org/D9866

rust: replace an unsafe use of transmute with a safe use of bytes-cast Differential Revision: https://phab.mercurial-scm.org/D9859

rust: use the bytes-cast crate to parse persistent nodemaps This crate casts pointers to custom structs, with compile-time safety checks, for easy and efficient binary data parsing. See https://crates.io/crates/bytes-cast and https://docs.rs/bytes-cast/0.1.0/bytes_cast/ Differential Revision: https://phab.mercurial-scm.org/D9788