Re: [Gnu-arch-users] Default version for star-merge

[Tom Lord]

    > From: address@hidden (James Blackwell)

    > I very recently taught a friend how to use arch. A day later, he came back
    > to me and essentially asked: Since star-merge is commonly used to merge
    > changes from the version you originally tagged from, why not make
    > the default version to star-merge the version you tagged from.

    > My initial reaction was a knee jerk one; the concept of parentage is much
    > too weak to have any sort of default version for a tool like star-merge.

    > But the more I thought about it, with a star topology, there really is a
    > parent-child relationship between the center of the star and the spokes.
    > Whats more, the idea that changes propogate both ways is a naive one; for
    > each person at the center of the star that is star-merging/cherry picking
    > from his spokes, there are anywhere from one to dozens of people merging
    > from him. 

    > Considering how star-merge happens to have a common case (the spoke
    > star-merging from center), then we can easily locate a sane default
    > argument for star-merge -- the version that we originally tagged from.

    > I actually think this is a good idea. Doing this slightly encourages
    > people to follow their parent tree a little closer.


It's an interesting idea but I worry that it will lead to mistakes.

Roughly speaking, only _half_ of the uses of star-merge are from the
branched-from version.  The other half are from a version branched
from yours.  In other words, half are of a parent into a child branch;
the other half are of a child into its parent branch.

Wouldn't habituating user's to omit the parameter for half of those
cases inevitably cause mistakes where a merge-from-child was intended
but a merge-from-parent occured?  In a tree of branches of depth
greater than 1, that kind of mistake, especially if not noticed right
away, could be a real mess.

(The current default for FROM, to use the tree-version, is an odd
choice in some sense.  It optimizes a non-common-case of the command.
But it makes more sense when you realize that, as a default that might
happen accidentally, it is at least far more likely to be a harmless
mistake.)

-t