revset: enforce "%d" to be interpreted as literal revision number (API) (BC) Before this change, `formatspec("%d", x)` results in `"%d" % int(x)`. This seems simple and correct until you consider `nullrev`. In revset, a direct "-1" symbol is equivalent to `tip` not `nullrev`. This is a subtle error that went undetected for a while. Wrapping the revision number inside 'rev()' remove the ambiguity, preserving nullrev value passed to formatspec. It got caught by the rebase code, were the following wrongly returned `[1]`: repo.revs("children(%d) and ancestors(%ld)", 0, [nullrev]) This is flagged as API, because `%d` can be used for non-revision integer argument of revset function. We probably need to introduce a new '%?' substitution to allow literal integer (maybe `%i`). However, the `%d` usage is currently widespread for revision number so it is important to fix this issue for `%d`. This choice is reinforced by the fact _intlist is implemented as revisions only. Restricting `%d` to revision only makes things more consistent. This bug can become especially tricky since `_intlist` recognize `nullrev` right. So `revs('%ld', [-1, 0])` ? select `[nullrev, 0]` but `revs('%ld', [-1])` is simplified and treated as `%d` selecting `[tip]`. Another side effect is that "%d" of an unknown revision simply match nothing. It was previously raising and error. This is consistent with what "%ld" (and `_intlist`) is doing, so it seems like a good move.