Re: how to use git merge -s subtree?

Sean [off-list ref] writes:

In the case of the "--follow" option though, the user might be forgiven
for thinking in terms of files rather than paths.  Even the git-log
documentation says for "--follow", "Continue listing the history of a
file beyond renames".   Which at least implies that Git knows about
file history, rather than just paths.

But you know git does not know nor care about "file" history.

And the thing is, I just tried this:

  $ git log --follow --pretty=short --stat gitk-git/gitk | head -n 20
  commit 62ba5143ec2ab9d4083669b1b1679355e7639cd5
  Author: Junio C Hamano [off-list ref]

      Move gitk to its own subdirectory

   gitk => gitk-git/gitk |    0 
   1 files changed, 0 insertions(+), 0 deletions(-)

  commit 7388bcbc5431552718dde5c3259d861d2fa75a12
  Author: Paul Mackerras [off-list ref]

      gitk: Use the UI font for the diff/old version/new version radio buttons

   gitk |    6 +++---
   1 files changed, 3 insertions(+), 3 deletions(-)

  commit cca5d946d692fde7ea5408a694cb4b1c97a5a838
  Author: Paul Mackerras [off-list ref]

      gitk: Simplify the code for finding commits

So there is something else going on, if David actually tried to
follow "B/foo" that was subtree-merged from a parent that had it
at toplevel "foo" and "log --follow" did not work for him.

Two things that come to mind offhand are that (1) --follow looks
for a path that has similar contents elsewhere only when the
path it is following in the child disappears in the parent.  So
if you start from B/foo that was subtree-merged (i.e. the other
parent has foo at the top) into a parent that already had B/foo,
it will not follow the other parent that does not have B/foo;
(2) I do not know if the original example by David tried to use
"-n $count" offhand, but it seems that currently --follow does
not play well with -n (try the above gitk-git/gitk without
piping the result into "head -n 20" but instead by limiting with
"git log -3 --follow ..."); if that is the case that definitely
is a bug.