Merge branch 'so/log-diff-merge'

"git log" learned "--diff-merges=<style>" option, with an
associated configuration variable log.diffMerges.

* so/log-diff-merge:
  doc/diff-options: document new --diff-merges features
  diff-merges: introduce log.diffMerges config variable
  diff-merges: adapt -m to enable default diff format
  diff-merges: refactor set_diff_merges()
  diff-merges: introduce --diff-merges=on

1 files changed, 31 insertions, 0 deletions

diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
index 6cca8b84a6..87def81699 100755
--- a/t/t4013-diff-various.sh
+++ b/t/t4013-diff-various.sh
@@ -452,6 +452,37 @@ diff-tree --stat --compact-summary initial mode
 diff-tree -R --stat --compact-summary initial mode
 EOF
 
+test_expect_success 'log --diff-merges=on matches --diff-merges=separate' '
+	git log -p --diff-merges=separate master >result &&
+	process_diffs result >expected &&
+	git log -p --diff-merges=on master >result &&
+	process_diffs result >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'deny wrong log.diffMerges config' '
+	test_config log.diffMerges wrong-value &&
+	test_expect_code 128 git log
+'
+
+test_expect_success 'git config log.diffMerges first-parent' '
+	git log -p --diff-merges=first-parent master >result &&
+	process_diffs result >expected &&
+	test_config log.diffMerges first-parent &&
+	git log -p --diff-merges=on master >result &&
+	process_diffs result >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'git config log.diffMerges first-parent vs -m' '
+	git log -p --diff-merges=first-parent master >result &&
+	process_diffs result >expected &&
+	test_config log.diffMerges first-parent &&
+	git log -p -m master >result &&
+	process_diffs result >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'log -S requires an argument' '
 	test_must_fail git log -S
 '