bookmarks: keep bookmarks in .hg/store if new config set Bookmarks storage consists of two parts: (1) the set of bookmarks and their positions, and (2) the current bookmark. The former can get updated by exchange, while the latter cannot. However, they are both stored in directly .hg/ and protected by repo.wlock(). As a result, ugly workarounds were needed. This patch introduces a new config option to store the set of bookmarks and their positions in .hg/store/ but still storing the current bookmark directory in .hg/. The config option only takes effect at repo creation time. It results in a new requirement being set. Differential Revision: https://phab.mercurial-scm.org/D6387

bookmark: also make bookmark cache depends of the changelog Since the changelog is also used during the parsing of bookmark data, it should be listed as a file cache dependency. This fix the race condition we just introduced a test for. This is a simple fix that might lead bookmark data to be invalidated more often than necessary. We could have more complicated code to deal with this race in a more "optimal" way. I feel it would be unsuitable for stable. In addition, the performance impact of this is probably minimal and I don't foresee the more advanced fix to actually be necessary.

localrepo: grab mixedrepostorecache class from 526750cdd02d On default, Martin von Zweigbergk <martinvonz@google.com> introduced a more advance filecache decorator. I need this decorator to fix a bug on stable. So I am grafting the relevant part of 526750cdd02d.

bookmark: add a test for a race condition on push Bookmark pointing to unknown nodes are ignored. Later these ignored bookmarks are dropped when writing the file back on disk. On paper, this behavior should be fine, but with the current implementation, it can lead to unexpected bookmark deletions. In theory, to make sure writer as a consistent view, taking the lock also invalidate bookmark data we already loaded into memory. However this invalidation is incomplete. The data are stored in a `filecache` that preserve them if the bookmark related file are untouched. In practice, the bookmark data in memory also depends of the changelog content, because of the step checking if the bookmarks refers to a node known to the changelog. So if the bookmark data were loaded from an up to date bookmark file but filtered with an outdated changelog file this go undetected. This condition is fairly specific, but can occurs very often in practice. We introduce a test recreating the situation. The test comes in an independant changeset to show it actually reproduce the situation. The fix will come soon after. A large share of the initial investigation of this race condition was made by Valentin Gatien-Baron <valentin.gatienbaron@gmail.com>.