hgweb: add test regarding filtering and hgweb Since 4d1671b39168 hgweb is broken with filtering. This changeset add test that should pass once it is fixed. Test currently broken are commented and will be uncommented by changeset that fix them. The filelog test is currently passing because we already have some hack in core regarding filelog (see 518c1403838f).

get-with-headers: add a --headeronly switch In some case we do not care about the actual rendering.

tests: more comment cleanup related to obsolescence

test: fix in-test comments related to obsolescence The `ui.prevent-unstable` option never made it into core. It always behaves this way when obsolescence feature is enabled. See changesets c5bd753c5bc6, bacf55bd8f90 and 0f5a0a2073a8 for details.

stream_in: write the remote branchcache for a usage as wide as possible Writing cache for unfiltered repo only is barely useful, Most repo user are now at least use the `hidden` filter. This changeset now assigns the remote cache for a filter as low as possible for a wider reuse as possible.

destroyed: update `unserved` branchcache instead Before this changesets the `destroyed` function updated the branchcache for unfiltered repository. As seen in a previous changeset, Read only repo does not cares about the unfiltered repo. We now update it for `unserved`.

destroyed: drop complex branchcache rebuilt logic The strip code used a trick to lower the cost of branchcache update after a strip. However is less necessary since we have branchcache collaboration. Invalid branchcache are likely to be cheaply rebuilt again a near subset of the repo. Moreover, this trick would need update to be relevant in the now filtered repository world. It currently update the unfiltered branchcache that few people cares about. Make it smarter on that aspect would need complexes update of the calling logic So this mechanism is: - Arguably needed, - Currently irrelevant, - Hard to update and I'm dropping it. We now update the branchcache in all case by courtesy of the read only reader. This changeset have a few expected impact on the testsuite are different cache are updated.