repoview: have unfilteredpropertycache using the underlying cache A `unfilteredpropertycache` is a kind of `propertycache` used on `localrepo` to unsure it will always be run against unfiltered repo and stored only once. As the cached value is never stored in the repoview instance, the descriptor will always be called. Before this patch such calls always result in a call to the `__get__` method of the `propertycache` on the unfiltered repo. That was recomputing a new value on every access through a repoview. We can't prevent the repoview's `unfilteredpropertycache` to get called on every access. In that case the new code makes a standard attribute access to the property. If a value is cached it will be used. The `propertycache` test file have been augmented with test about this issue.

repoview: make propertycache.setcache compatible with repoview Propertycache used standard attribute assignment. In the repoview case, this assignment was forwarded to the unfiltered repo. This result in: (1) unfiltered repo got a potentially wrong cache value, (2) repoview never reused the cached value. This patch replaces the standard attribute assignment by an assignment to `objc.__dict__` which will bypass the `repoview.__setattr__`. This will not affects other `propertycache` users and it is actually closer to the semantic we need. The interaction of `propertycache` and `repoview` are now tested in a python test file.

i18n-pt_BR: synchronized with 1aaefba2a3a9

merge with stable

histedit: add more detailed help about "--outgoing"

histedit: abort if there are multiple roots in "--outgoing" revisions Before this patch, if there are multiple roots in "--outgoing" revisions, result of "histedit --outgoing" depends on the parent of the working directory. It succeeds only when the parent of the working directory is a descendant of the oldest root in "--outgoing" revisions, and fails otherwise. It seems to be ambiguous and difficult for users. This patch makes "histedit --outgoing" abort if there are multiple roots in "--outgoing" revisions always.

discovery: abort also when pushing multiple headed new branch Before this patch, pushing with --new-branch permits to create multiple headed branch on the destination repository. But permitting to create new branch should be different from permitting to create multiple heads on branch. This patch prevents from careless pushing multiple headed new branch, and requires --force to push such branch forcibly.

branchmap: stop looking for stripped branch Since repoview in 2.5 we do not make special call to `branchmap` when stripping. We just recompute the branchmap from a lower subset that still has valid branchmap. So I'm dropping this dead code.

branchmap: remove the droppednodes logic It was unused. note how it is only extended if the list is empty. So it's always empty at the end. We could try to fix that, however this would part of the code is to be removed in the next changeset as we do not run `branchmap` on truncated repo since `repoview` in 2.5.

branchmap: fix blank line position The blank line was after was after the `if` condition instead of before.