range-diff: optionally accept pathspecs
The `git range-diff` command can be quite expensive, which is not a
surprise given that the underlying algorithm to match up pairs of
commits between the provided two commit ranges has a cubic runtime.
Therefore it makes sense to restrict the commit ranges as much as
possible, to reduce the amount of input to that O(N^3) algorithm.
In chatty repositories with wide trees, this is not necessarily
possible merely by choosing commit ranges wisely.
Let's give users another option to restrict the commit ranges: by
providing a pathspec. That helps in repositories with wide trees because
it is likely that the user has a good idea which subset of the tree they
are actually interested in.
Example:
git range-diff upstream/main upstream/seen HEAD -- range-diff.c
This shows commits that are either in the local branch or in `seen`, but
not in `main`, skipping all commits that do not touch `range-diff.c`.
Note: Since we piggy-back the pathspecs onto the `other_arg` mechanism
that was introduced to be able to pass through the `--notes` option to
the revision machinery, we must now ensure that the `other_arg` array is
appended at the end (the revision range must come before the pathspecs,
if any).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t3206-range-diff.sh b/t/t3206-range-diff.sh
index d12e4e4..459beaf 100755
--- a/t/t3206-range-diff.sh
+++ b/t/t3206-range-diff.sh
@@ -162,7 +162,7 @@
'
test_expect_success 'A^{/..} is not mistaken for a range' '
- test_must_fail git range-diff topic^.. topic^{/..} 2>error &&
+ test_must_fail git range-diff topic^.. topic^{/..} -- 2>error &&
test_i18ngrep "not a commit range" error
'
@@ -772,6 +772,17 @@
test_cmp expect actual
'
+test_expect_success 'ranges with pathspecs' '
+ git range-diff topic...mode-only-change -- other-file >actual &&
+ test_line_count = 2 actual &&
+ topic_oid=$(git rev-parse --short topic) &&
+ mode_change_oid=$(git rev-parse --short mode-only-change^) &&
+ file_change_oid=$(git rev-parse --short mode-only-change) &&
+ grep "$mode_change_oid" actual &&
+ ! grep "$file_change_oid" actual &&
+ ! grep "$topic_oid" actual
+'
+
test_expect_success 'submodule changes are shown irrespective of diff.submodule' '
git init sub-repo &&
test_commit -C sub-repo sub-first &&
