merge: respect parents order when using `graft` on a merge, this time for real See a4ca0610c754. potherp1 is a boolean variable that means "pother is ctx.p1", and parents is naturally [ctx.p1, ctx.p2]. pctx is always removed from parents, so if pctx is parents[0], then we end up using parents[1] as pother. To be true to its name, potherp1 should then be True only when pctx is at parents[1].

py3: don't double-convert "opts" to bytes The "opts" are already converted to bytes at the beginning of the function. Doing it twice results in a crash, which makes test-uncommit.t fail. The extra call was added recently, in ff1ff2aae132 (uncommit: add support to modify the commit message and date, 2019-09-07). test-uncommit.t passes again after this patch. Differential Revision: https://phab.mercurial-scm.org/D6864