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.
adding a
diff -r c19d34741b0a a
--- a/a
+++ b/a
@@ -1,1 +1,1 @@
-a
+abc
adding b
M a
resolving manifests
force None allow None moddirstate True linear True
ancestor a0c8bcbbb45c local a0c8bcbbb45c remote 1165e8bd193e
a versions differ, resolve
remote created b
getting b
merging a
resolving a
file a: other d730145abbf9 ancestor b789fdd96dc2
resolving manifests
force None allow 1 moddirstate True linear True
ancestor 1165e8bd193e local 1165e8bd193e remote 1165e8bd193e
changeset: 1:1e71731e6fbb
tag: tip
user: test
date: Thu Jan 1 00:00:00 1970 +0000
summary: 2
changeset: 1:1e71731e6fbb5b35fae293120dea6964371c13c6
tag: tip
user: test
date: Thu Jan 1 00:00:00 1970 +0000
files: a b
description:
2
changeset: 0:c19d34741b0a4ced8e4ba74bb834597d5193851e
user: test
date: Thu Jan 1 00:00:00 1970 +0000
files: a
description:
1
diff -r 1e71731e6fbb a
--- a/a
+++ b/a
@@ -1,1 +1,1 @@
-a2
+abc