debugmergestate: make templated

Authored by martinvonz.


debugmergestate: make templated

Our IntelliJ team wants to be able to read the merge state in order to
help the user resolve merge conflicts. They had so far been reading
file contents from p1() and p2() and their merge base. That is not
ideal for several reasons (merge base is not necessarily the "graft
base", renames are not handled, commands like hg update -m is not
handled). It will get especially bad as of my D7827. This patch makes
the output s a templated. I haven't bothered to make it complete
(e.g. merge driver states are not handled), but it's probably good
enough as a start.

I've done a web search for "debugmergestate" and I can't find any
indication that any tools currently rely on its output. If it turns
out that we get bug reports for it once this is released, I won't
object to backing this patch out on the stable branch (and then
perhaps replace it by a separate command, or put it behind a new

The changes in test-backout.t are interesting, in particular this:

-    other path: foo (node not stored in v1 format)
+    other path:  (node foo)

I wonder if that means that we actually read v1 format
incorrectly. That seems to be an old format that was switched away
from in 2014, so it doesn't matter now anyway.

Differential Revision: https://phab.mercurial-scm.org/D8120


martinvonzFeb 14 2020, 12:14 AM
Differential Revision
D8120: debugmergestate: make templated
rHG382f4f09f0bd: tests: add tests of debugmergestate with unresolved/resolved path conflicts