Re: [PATCH] Fix "git log --parent -m" from emitting duplicated parent info

"Marco Costalba" [off-list ref] writes:

Indeed we can use and _do_ use --full-history not only for printing
all revisions but to _walk_ the tree in a certain way, different from
default.

Yes, --full-history essentially tells the machnery to walk all
side branches even when a merge takes all the specified paths
from one parent's version.  You will end up walking all five
branches from the first pentapus "addafaf" in git.git history,
even if history simplification with pathspec would have narrowed
it down to three paths if you did not give that option.

IMHO --parents + --full-history is absolutely legal because the first
flag indicate how to walk the tree and the second flag indicate what
to show to the user.

I think we are in agreement.  You are telling the machinery to
walk all five branches with --full-history.  But you are not
telling the machinery to keep the intermediate commits (i.e. you
do not give --sparse), so these five branches can be simplified
to lead to the same parent.  I think I was confused by dense vs
simplify_history when I wrote that message in the thread
Johannes pointed out:

	http://thread.gmane.org/gmane.comp.version-control.git/29222

Making the duplicate parent removal depend on "dense" makes
sense, but the rewrite_parent() codepath is used only when dense
anyway.

Thanks for a timely objection and sanity checking.