Re: [PATCH] fetch: skip on-demand checking when no submodules are configured

Jens Lehmann [off-list ref] writes:

It makes no sense to do the - possibly very expensive - call to "rev-list
<new-ref-sha1> --not --all" in check_for_new_submodule_commits() when
there aren't any submodules configured.

Leave check_for_new_submodule_commits() early when no name <-> path
mappings for submodules are found in the configuration. To make that work
reading the configuration had to be moved further up in cmd_fetch(), as
doing that after the actual fetch of the superproject was too late.

Reported-by: Martin Fick <redacted>
Signed-off-by: Jens Lehmann <redacted>
---

This achieves the first goal: Don't let people pay a performance penalty
when they don't even use submodules. On Michael's test repo from [1] the
time for a full fetch went down from 142 seconds (current master) to one
second which is - not surprisingly - the same as using current master
with the --no-recurse-submodules option.

Now back to the drawing board to fix the performance regression for those
people who are using submodules ...

[1] http://comments.gmane.org/gmane.comp.version-control.git/177103

Thanks.