Re: git merge vs git commit

Matthieu Moy [off-list ref]:

quoted

Russell King [off-list ref] writes:

Hi,

Using git 1.5.4.5, I notice that the result from git merge and git commit
are different in an unexpected way.

Take the following tree:

     B---C---D---E2
    /
  -A1
    \
     F---G---H---I3

(letters represent commits, numbers represent where the references are).

Your current head is '1', and you want to merge branches '2' and '3', so
you use:

     git merge 2 3

AAUI, "git merge 2 3" doesn't mean "merge 2 and 3 together", but
"merge 2 and 3 with the current HEAD". So, what you wanted was :

git checkout 1
git merge 2

And what you did was an octopus merge of A, E and I (which ends up
being the same since A is anyway the common ancestor of E and I).

Now, this doesn't explain why the conflicted merge gives a result
different from the other.

(I'm not on the list, please CC)

Reading the whole thread I think we have an explanation: octupus-merge
learned to remove reduntant parents and does so in the clean merge
case, but merge in general does not it; this is what happens in the
conflict case.

However it remains that three parents are to be expected with the
given user action

Ulrik Sverdrup