Mercurial: Any way to “merge and discard changes”?

Question

I have a graphlog that looks something like this:

(snip)
  | |
  | o    1) Other Dev: Commit
  | | \\
  o | |  2) Me: Commit
/ | | |
| | o |  3) Other Dev: C         


        

Answer 1

Yes. The internal:local builtin merge tool.

$ hg merge 4 --tool internal:local

Similarly there's internal:other that picks the other version of files as the merged version.

Here's an example to clarify what's going on, start off with a repo with a single file:

$ echo a >> a
$ hg ci -Am.
adding a
$ echo a >> a
$ hg ci -Am.

Branch it and put a conflict in a:

$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo b >> a

Also add another file just in the merged in branch:

$ echo b >> b
$ hg ci -Am.
adding b
created new head

Go back and merge the anonymous head:

$ hg up 1
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge 2 --tool internal:local
1 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)

Naturally at this point without the merge tool we'd get a conflict on a. But using the merge tool, we're telling Mercurial to take the version of the first parent on every file that the merged with cset has also touched.

$ hg st
M a
M b
$ cat a
a
a
$ cat b
b