destutil: choose non-closed branch head at first (BC)
Before this patch, destupdate() returns the tipmost (descendant)
branch head regardless of closed or not. But updating to closed branch
head isn't reasonable for ordinary workflow, because:
- "hg heads" doesn't show closed heads (= updated parent itself) by
default
- subsequent committing on it re-opens closed branch
even if inactivation of closed head is needed, update destination
isn't it, because it should be merged into to another branch in
such case.
This patch chooses non-closed descendant branch head as default update
destination at first. If all descendant branch heads are closed,
destupdate() returns the tipmost closed branch head.
For simplicity, this patch chooses adding _destupdatebranchfallback()
instead largely changing _destupdatebranch().
This patch changes not only normal lookup code path, but also the "no
default branch" code path, for consistency.
running: init test1
result: None
running: add foo
result: 0
running: commit -m commit1 -d 2000-01-01 foo
result: None
running: commit -m commit2 -d 2000-01-02 foo
result: None
running: log -r 0
changeset: 0:0e4634943879
user: test
date: Sat Jan 01 00:00:00 2000 +0000
summary: commit1
result: None
running: log -r tip
changeset: 1:45589e459b2e
tag: tip
user: test
date: Sun Jan 02 00:00:00 2000 +0000
summary: commit2
result: None