test: add test for the issue introduced by e410be860393 (issue3669) e410be860393 (released as Mercurial 2.3) introduced the issue that the revset program started with 40 hexadecimal letters caused unexpected result at "hg log" execution. This issue was already fixed by bde1185f406c (released as 2.3.1), but there is no test to examine whether this issue is certainly fixed or not: no test fails even if bde1185f406c is backed out. This patch adds test for this issue. Added test is also confirmed to fail, when it is tested against: - Mercurial 2.3, or - Mercurial 2.3.1 or later with backing bde1185f406c out