comparison tests/test-backout.t @ 44396:acbfa31cfaf2

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
flag).

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

44395:382f4f09f0bd

  $ hg backout -r 'desc("capital three")' --tool internal:fail
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges
  [1]
  $ hg status
  $ hg debugmergestate
  * version 2 records
  local: b71750c4b0fdf719734971e3ef90dbeab5919a2d
  other: a30dd8addae3ce71b8667868478542bc417439e6
  file extras: foo (ancestorlinknode = 91360952243723bd5b1138d5f26bd8c8564cb553)
  file: foo (record type "F", state "u", hash 0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33)
    local path: foo (flags "")
    ancestor path: foo (node f89532f44c247a0e993d63e3a734dd781ab04708)
    other path: foo (node f50039b486d6fa1a90ae51778388cad161f425ee)
  $ mv .hg/merge/state2 .hg/merge/state2-moved
  $ hg debugmergestate
  * version 1 records
  local: b71750c4b0fdf719734971e3ef90dbeab5919a2d
  file: foo (record type "F", state "u", hash 0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33)
    local path: foo (flags "")
    ancestor path: foo (node f89532f44c247a0e993d63e3a734dd781ab04708)
    other path: foo (node not stored in v1 format)
  $ mv .hg/merge/state2-moved .hg/merge/state2
  $ hg resolve -l  # still unresolved
  U foo
  $ hg summary
  parent: 2:b71750c4b0fd tip

44396:acbfa31cfaf2

  $ hg backout -r 'desc("capital three")' --tool internal:fail
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges
  [1]
  $ hg status
  $ hg debugmergestate -v
  v1 and v2 states match: using v2
  local: b71750c4b0fdf719734971e3ef90dbeab5919a2d
  other: a30dd8addae3ce71b8667868478542bc417439e6
  file: foo (state "u")
    local path: foo (hash 0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33, flags "")
    ancestor path: foo (node f89532f44c247a0e993d63e3a734dd781ab04708)
    other path: foo (node f50039b486d6fa1a90ae51778388cad161f425ee)
    extra: ancestorlinknode = 91360952243723bd5b1138d5f26bd8c8564cb553
  $ mv .hg/merge/state2 .hg/merge/state2-moved
  $ hg debugmergestate -v
  no version 2 merge state
  local: b71750c4b0fdf719734971e3ef90dbeab5919a2d
  other: b71750c4b0fdf719734971e3ef90dbeab5919a2d
  file: foo (state "u")
    local path: foo (hash 0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33, flags "")
    ancestor path: foo (node f89532f44c247a0e993d63e3a734dd781ab04708)
    other path:  (node foo)
  $ mv .hg/merge/state2-moved .hg/merge/state2
  $ hg resolve -l  # still unresolved
  U foo
  $ hg summary
  parent: 2:b71750c4b0fd tip