Fix long-standing excessive file merges
Since switching to the multihead approach, we've been creating
excessive file-level merges where files are marked as merged with
their ancestors.
This explicitly checks at commit time whether the two parent versions
are linearly related, and if so, reduces the file check-in to a
non-merge. Then the file is compared against the remaining parent,
and, if equal, skips check-in of that file (as it's not changed).
Since we're not checking in all files that were different between
versions, we no longer need to mark so many files for merge. This
removes most of the 'm' state marking as well.
Finally, it is possible to do a tree-level merge with no file-level
changes. This will happen if one user changes file A and another
changes file B. Thus, if we have have two parents, we allow commit to
proceed even if there are no file-level changes.
pulling from ../test1
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 2 changes to 2 files
(run 'hg update' to get a working copy)
pulling from ../test2
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
(run 'hg update' to get a working copy)
changeset: 2:3ef543305655
tag: tip
parent: 0:22a449e20da5
user: test
date: Thu Jan 1 00:00:00 1970 +0000
summary: chmod +x a
changeset: 1:c6ecefc45368
user: test
date: Thu Jan 1 00:00:00 1970 +0000
summary: a updated
changeset: 2:3ef543305655
tag: tip
parent: 0:22a449e20da5
user: test
date: Thu Jan 1 00:00:00 1970 +0000
summary: chmod +x a
changeset: 1:c6ecefc45368
user: test
date: Thu Jan 1 00:00:00 1970 +0000
summary: a updated
changeset: 0:22a449e20da5
user: test
date: Thu Jan 1 00:00:00 1970 +0000
summary: added a b
resolving manifests
merging a
resolving a
-rwxr-x---
-rwxr-x---