strip: strip obsmarkers exclusive to the stripped changeset This is it, `hg strip --rev X` will now also remove obsolescence markers exclusive to X. Since a previous changeset, the obsmarkers has been backed up in the strip backup bundle, so it is possible to restore them. Note: stripping obsmarkers means the precursors of the stripped changeset might no longer be obsolete after the strip. Stripping changeset without obsmarkers can be useful when building test case. So It is possible to disable the stripping of obsmarkers using the 'devel.strip-obsmarkers' config option. Test change have been carefully validated.

strip: do not include obsolescence markers for the temporary bundle When stripping, we need to put all non-stripped revisions "above" the stripped ones in a "temporary-bundle" while we strip the targets revision. Then we reapply that bundle to restore these non-stripped revisions (with a new revision numbers). We skip the inclusion of obsolescence markers in that bundle. This is safe since all obsmarkers we plan to strip will be backed-up in the strip backup bundle. Including the markers would create issue in some case were we try to strip a prune markers that is "relevant" to a revision in the "temporary-bundle". (note: we do not strip obsmarkers yet)

exclusive-markers: update the dedicated test with list of exclusive markers We now display data about the "exclusive markers" in the test dedicated to relevant and exclusive markers computation and usage. Each output have been carefully validated

obsolete: add a function to compute "exclusive-markers" for a set of nodes This set will be used to select the obsmarkers to be stripped alongside the stripped changesets. See the function docstring for details. More advanced testing is introduced in the next changesets to keep this one simpler. That extra testing provides more example.

test-obsolete-bundle-strip: check all changesets in the isolated prune case We also want to check the result of the various computations when both changesets are selected (the pruned changesets and its parents).

test-obsolete-bundle-strip: add testing of markers backup during strip When applicable, we strip the revision tested in the test and we check that the backup bundle contains the appropriate markers.

strip: also backup obsmarkers We are about to give 'strip' the ability to remove obsmarkers. Before we start removing data we must make sure it is preserved somewhere. So the backup bundle created by 'strip' now contains obsmarkers.

tests: fix run-tests when there's a bad #if in a test That has (and still does) caused the test to be skipped, but without this fix it was possible to exit this block of code without clearing the output channel, which poisoned the channel list for later test method runs. Fix this by always clearing the channel in a finally. The test for this is somewhat unfortunate. Sadly, I couldn't get a way to reproduce this with less than 2n+1 test cases, nor could I get it to reproduce reliably without the sleep statements. It's also crucial that the test with the broken #if be smaller (in terms of byte count) than the sleeping tests, so that it runs first and would poison the channel list prior to another test needing that entry from the list.

tests: make run-tests fail early if no channel is found I hit a weird corner case in run-tests where a test that caused an exception to be raised was breaking everything with an unbound variable error a few lines down because channel was never getting set in this for loop. By adding an `else` clause to this for loop, we can explode right away if we can't find a channel and give the developer a better chance at figuring out what's going on.

dispatch: convert exception payload to bytes more carefully We were previously depending on str() doing something reasonable here, and we can't depend on the objects in question supporting __bytes__, so we work around the lack of direct bytes formatting.