Clarification: is the hgmerge program always called?

[Vadim Gelfer]

On 5/15/06, Christian Boos <cboos at neuf.fr> wrote:

> While doing some updates in the Wiki (turning "hg update -m"
> into "hg merge"), I was a bit surprised by the explanations
> concerning the merge program: it was written that Mercurial
> tries to resolve the merge on its own, and only when it fails
> to do so, calls an external merge program...

mercurial does not need to call hgmerge if only one parent modifies
file, because it is ok to just take parent's version. hgmerge is
called only if both parents modify file.