Mercurial: order of version numbers compatible with topological order of change sets?

Question

For two change sets X and Y in the same Mercurial repository, the following condition is true:

if X is the parent of Y, then revision (X) <revision (Y)

?

If this is true, is it a specification or how is it currently implemented? In other words, is it possible to rely on this condition for future releases of Mercurial?

Answer 1

Yes, revision numbers reflect some topological ordering of change sets.

The revision numbers you see are just the order of the revlog entries for the change log, and the revlogs are always topologically sorted. In other words, revision numbers are transmitted sequentially in this repository, and you cannot pull out a child before you pull its ancestors.