run-tests: check if stream is a tty before using color Previous implementation (e80041832eec) checked only if sys.stderr was a tty which was less general. Also makes sure that colors is never used if pygments is not available, irrespective of --color flag value.

tests: rewrite test-rebase-detach.t using drawdag This makes it much clearer because each test case can have exactly the graph it wants (no extra cruft just because other tests want it). Differential Revision: https://phab.mercurial-scm.org/D94

tests: simplify config in test-rebase-detach.t Differential Revision: https://phab.mercurial-scm.org/D93

drawdag: include files from both parents in merge commits Consider a graph like this: D |\ B C |/ A drawdag will add a file called A in commit A, file B in B, file C in C. That's fine and expected. In merge commits like D, I would expect the files and their contents to be taken from the parent commits, so commit D in this example would have files A, B, and C. However, drawdag will instead add the file D compared to the first parent. Depending on whether B or C got a smaller nodeid, the contents of D would be {A, B, D} or {A, C, D}. This patch changes it to to be {A, B, C}. Differential Revision: https://phab.mercurial-scm.org/D92