obsolescence: add test case A-1 for obsolescence markers exchange About 3 years ago, in August 2014, the logic to select what markers to select on push was ported from the evolve extension to Mercurial core. However, for some unclear reasons, the tests for that logic were not ported alongside. I realised it a couple of weeks ago while working on another push related issue. I've made a clean up pass on the tests and they are now ready to integrate the core test suite. This series of changesets do not change any logic. I just adds test for logic that has been around for about 10 versions of Mercurial. They are a patch for each test case. It makes it easier to review and postpone one with documentation issues without rejecting the wholes series. This patch introduce case A-1: pushing a single head Each test case comes it in own test file. It help parallelism and does not introduce a significant overhead from having a single unified giant test file. Here are timing to support this claim. # Multiple test files version: # run-tests.py --local -j 1 test-exchange-*.t 53.40s user 6.82s system 85% cpu 1:10.76 total 52.79s user 6.97s system 85% cpu 1:09.97 total 52.94s user 6.82s system 85% cpu 1:09.69 total # Single test file version: # run-tests.py --local -j 1 test-exchange-obsmarkers.t 52.97s user 6.85s system 85% cpu 1:10.10 total 52.64s user 6.79s system 85% cpu 1:09.63 total 53.70s user 7.00s system 85% cpu 1:11.17 total