internals: minor rewriting of revlogs documentation In preparation for formalizing revlog version 2. Differential Revision: https://phab.mercurial-scm.org/D5558

tests: make HGCATAPULTSERVERPIPE imply HGTESTCATAPULTSERVERPIPE I had attempted to do this before, but missed this case. This makes it so that one can do the following to get catapult traces that include both the .t test name (and non-hg commands run by that .t test) *and* the hg-internal tracing, in one trace: HGCATAPULTSERVERPIPE=/tmp/catapult.pipe run-tests.py <args> Without this change, we need to specify both `HG{,TEST}CATAPULTSERVERPIPE`; if we specify just the TEST one, we only get the .t tests (no hg-internals), which is working as intended. If we specify the non-TEST one, we only get the hg-internals (not the rest of the .t test), which was not intended. If you want to restore the previous behavior (just hg internals, not the stuff from the .t tests), run like: HGTESTCATAPULTSERVERPIPE=/dev/null \ HGCATAPULTSERVERPIPE=/tmp/catapult.pipe \ run-tests.py <args> Differential Revision: https://phab.mercurial-scm.org/D5569

tests: add test for warning on histedit with tagged commits This is a follow-up patch to 7b7e081f8954 (D5494). Differential Revision: https://phab.mercurial-scm.org/D5552

extdiff: move external tool command line building into separate function

test: explicit a rebase source in test-rebase-collapse.t At the time of the rebase, the current revision is `null` so this rebase should fail. However, a current bug in formatspec makes it pass, we fix rebase call of the "affected" test to express its actual intent before we fix the actual bug in a later changeset.

tags: join string that's unnecessarily split across lines Differential Revision: https://phab.mercurial-scm.org/D5574