bisect: add `-G` to an `hg log` command in a test This helps readers see what shape of DAG to expect Differential Revision: https://phab.mercurial-scm.org/D9373

bisect: refactor to work on a list of revspecs This will allow adding a `--rev` flag that can be passed more than once. Differential Revision: https://phab.mercurial-scm.org/D9372

copies: simplify the call to _merge_copies_dict Let's get the argument into the right order, then call the function once. Differential Revision: https://phab.mercurial-scm.org/D9417

copies: fast path no-op merge If the two sides of the merge are the same (they come an unaltered common ancestors) we don't need any merging. Differential Revision: https://phab.mercurial-scm.org/D9415

copies-rust: encapsulate internal sets on `changes` The goal is to eventually stop creating the underlying set. So we need to encapsulate the call first. Differential Revision: https://phab.mercurial-scm.org/D9306

copies-rust: pre-indent some code to clarify the next patch The next patch will need this new indentation, having it done explicitly beforehand makes that next patch clearer. Differential Revision: https://phab.mercurial-scm.org/D9305

copies-rust: combine the iteration over remove and copies into one In the underlying data, the copies information and the removal information are interleaved. And in the consumer code, the consumption could be interleaved too. So, we make the processing closer to the underlying data by fusing the two iterators into one. Later, we will directly consume the underlying data and that logic to combine the two iterators will be unnecessary. Differential Revision: https://phab.mercurial-scm.org/D9304