py3: convert arbitrary exception object to byte string more reliably Our exception types implement __bytes__(), which should be tried first. Do lossy encoding conversion as a last resort.

build: delay version computation on macOS builds The way HGVER is evaluated now, it'll be evaluated at the beginning of the make execution - with this change, it's evaluated when it gets to that command, at which point the version file it's looking for is sure to exist and be up-to-date. Differential Revision: https://phab.mercurial-scm.org/D224

color: remove warnings if term is not formatted (==dumb or !ui.formatted()) If the user sets color.mode=terminfo, and then runs in the shell inside of emacs (so TERM=dumb), the previous behavior was that it would warn about no terminfo entry for setab/setaf, and then warn about 'failed to set color mode to terminfo'. The first warning is silenced by carrying 'formatted' through to _terminfosetup, the second is silenced by using 'formatted' instead of ui.formatted(). If --color=on (or ui.color=always) is specified, this will still warn, since the formatted boolean is set to true in these cases. Differential Revision: https://phab.mercurial-scm.org/D223

rpms: add chg I'm not sure if there's a reason chg is not added by default. If not, I would like to propose adding in this patch. Differential Revision: https://phab.mercurial-scm.org/D220

tests: demonstrate crash when trying to rebase merge without its parents As the test case shows, when "hg rebase -d G -r 'B + D + F'" is run on the following graph, we crash with traceback. It's reasonable to fail because we can not easily produce a correct rebased F. The problem is what diff to apply to either the rebased B or the rebased D. We could potentially produce the result by e.g. applying the (F-D) diff to the rebased B and then applying the reverse (E-D) diff on top, but that could result in merge conflicts in each of those steps, which we don't have a way of dealing with. So for now, let's just add a test case to demonstrate that we crash (i.e. the AssertionError is clearly incorrect since the user can run into it). F /| C E | | B D G \|/ A Differential Revision: https://phab.mercurial-scm.org/D212

tests: demonstrate broken rebase of merge with p1's successor in dest The fix in 8ede973597fd (rebase: handle successor targets (issue5198), 2016-04-11) only fixed the case where p2's successor was in the destination, and only when the successor was exactly the destination (i.e. not when the successor was an ancestor of it). This patch adds a test case for when p1's successor is in the destination. It adds another one for when the successor is an ancestor of the destination. To do that simply, it also rewrites the test case using drawdag. Differential Revision: https://phab.mercurial-scm.org/D211

bundle2: obtain repr() of exception in a python3-safe way This was exposed by other problems in bundle generation, but I'm not sure how to test it for now.

bundle2: use bytestr() instead of str() to convert part id to bytes This was exposed by trying to run previously-passing Python 3 tests.

bundle2: work around zip() being lazy in Python 3

bundle2: look for __next__ as well as next to identify iterators In Python 3, next is called __next__ and this was failing to catch some iterators.