localrepo: make invalidate avoid invalidating store inside transaction (API) Before this patch, invalidate() discards in-memory fncache changes, even inside transaction scope. Such changes should be written out at closing transaction. Otherwise, fncache might overlook newly added files. A file overlooked by fncache isn't accessible via store vfs, even if it actually exists in store. On the other hand, a non-existing file in fncache is less harmful, because fncachestore always examines whether a file actually exists or not before access. Therefore, discarding in-memory changes can be safely omitted. It is typical case that repo.invalidate() in streamclone is executed inside nested transaction. This patch makes invalidate() avoid invalidating store inside transaction. This patch focuses on describing only how invalidate() changes own behavior according to activity of transaction. Describing other detail of invalidate() in docstr will be done in another series, which refactors invalidate*() functions.

streamclone: force @filecache properties to be reloaded from file Before this patch, consumev1() invokes repo.invalidate() after closing transaction, to force @filecache properties to be reloaded from files at next access, because streamclone writes data into files directly. But this doesn't work as expected in the case below: 1. at closing transaction, repo._refreshfilecachestats() refreshes file stat of each @filecache properties with streamclone-ed files This means that in-memory properties are treated as valid. 2. but streamclone doesn't changes in-memory properties This means that in-memory properties are actually invalid. 3. repo.invalidate() just forces to examine file stat of @filecache properties at the first access after it Such examination should concludes that reloading from file isn't needed, because file stat was already refreshed at (1). Therefore, invalid in-memory cached properties (2) are unintentionally treated as valid (1). This patch invokes repo.invalidate() with clearfilecache=True, to force @filecache properties to be reloaded from file at next access. BTW, it is accidental that repo.invalidate() without clearfilecache=True in streamclone case seems to work as expected before this patch. If transaction is started via "filtered repo" object, repo._refreshfilecachestats() tries to refresh file stat of each @filecache properties on "filtered repo" object, even though all of them are stored into "unfiltered repo" object. In this case, repo._refreshfilecachestats() does nothing unintentionally, but this unexpected behavior causes reloading @filecache properties after repo.invalidate(). This is reason why this patch should be applied before making _refreshfilecachestats() correctly refresh file stat of @filecache properties.