test-casecollision-merge: fix the test D30 (055fee3547df) makes the error message unpredictable, therefore the fix. Differential Revision: https://phab.mercurial-scm.org/D494

run-tests: make per-line condition support testcase names 7340465bd added multiple test cases support. The latter has a problem - output lines cannot be made conditional with `#if`: ``` # COUNTEREXAMPLE: DOES NOT WORK #testcases A B $ command-foo common ouput #if A A's ouput #else B's ouput #endif common ouput ``` That's not trivial to fix (even if it works in test, `run-tests.py -i` may be suboptimal because diff algorithm does not know how to skip the `#if` lines, even if it does, it may have trouble figuring out whether a changed line belongs to inside a `#if` block or outside). Matching output lines conditionally is useful. 4eec2f04a added per-line condition support for hghave. This patch extends that to also support test case names. Differential Revision: https://phab.mercurial-scm.org/D466

simplemerge: refactor _picklabels to be more compact Use @martinvonz's suggestion from D376. Differential Revision: https://phab.mercurial-scm.org/D521

simplemerge: remove check for null context Differential Revision: https://phab.mercurial-scm.org/D520

run-tests: pass unicode to Pygments This is required on Python 3, and is more correct on Python 2 because Pygments is a unicode library.

run-tests: factor out highlight functions

run-tests: include "\n" in formatted message instead of calling writeln() So we don't have to strip "\n" from pygments output.