Merge branch 'rj/format-patch-auto-cover-with-interdiff'

"git format-patch --interdiff" for multi-patch series learned to
turn on cover letters automatically (unless told never to enable
cover letter with "--no-cover-letter" and such).

* rj/format-patch-auto-cover-with-interdiff:
  format-patch: assume --cover-letter for diff in multi-patch series
  t4014: cleanups in a few tests

Author: gitster

builtin/log.c

@@ -2382,6 +2382,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	if (cover_letter == -1) {
 		if (cfg.config_cover_letter == COVER_AUTO)
 			cover_letter = (total > 1);
+		else if ((idiff_prev.nr || rdiff_prev) && (total > 1))
+			cover_letter = (cfg.config_cover_letter != COVER_OFF);
 		else
 			cover_letter = (cfg.config_cover_letter == COVER_ON);
 	}

t/t3206-range-diff.sh

@@ -545,6 +545,20 @@ do
 	'
 done
 
+test_expect_success "--range-diff implies --cover-letter for multi-patch series" '
+	test_when_finished "rm -f v2-000?-*" &&
+	git format-patch -v2 --range-diff=topic main..unmodified &&
+	test_grep "^Range-diff against v1:$" v2-0000-cover-letter.patch
+'
+
+test_expect_success "explicit --no-cover-letter defeats implied --cover-letter" '
+	test_when_finished "rm -f v2-000?-*" &&
+	test_must_fail git format-patch --no-cover-letter \
+		-v2 --range-diff=topic main..unmodified &&
+	test_must_fail git -c format.coverLetter=no format-patch \
+		-v2 --range-diff=topic main..unmodified
+'
+
 test_expect_success 'format-patch --range-diff as commentary' '
 	git format-patch --range-diff=HEAD~1 HEAD~1 >actual &&
 	test_when_finished "rm 0001-*" &&

t/t4014-format-patch.sh

@@ -820,8 +820,8 @@ test_expect_success 'format-patch --notes --signoff' '
 '
 
 test_expect_success 'format-patch notes output control' '
+	test_when_finished "git notes remove HEAD || :" &&
 	git notes add -m "notes config message" HEAD &&
-	test_when_finished git notes remove HEAD &&
 
 	git format-patch -1 --stdout >out &&
 	! grep "notes config message" out &&
@@ -848,10 +848,10 @@ test_expect_success 'format-patch notes output control' '
 '
 
 test_expect_success 'format-patch with multiple notes refs' '
+	test_when_finished "git notes --ref note1 remove HEAD;
+			    git notes --ref note2 remove HEAD || :" &&
 	git notes --ref note1 add -m "this is note 1" HEAD &&
-	test_when_finished git notes --ref note1 remove HEAD &&
 	git notes --ref note2 add -m "this is note 2" HEAD &&
-	test_when_finished git notes --ref note2 remove HEAD &&
 
 	git format-patch -1 --stdout >out &&
 	! grep "this is note 1" out &&
@@ -892,10 +892,10 @@ test_expect_success 'format-patch with multiple notes refs' '
 test_expect_success 'format-patch with multiple notes refs in config' '
 	test_when_finished "test_unconfig format.notes" &&
 
+	test_when_finished "git notes --ref note1 remove HEAD;
+			    git notes --ref note2 remove HEAD || :" &&
 	git notes --ref note1 add -m "this is note 1" HEAD &&
-	test_when_finished git notes --ref note1 remove HEAD &&
 	git notes --ref note2 add -m "this is note 2" HEAD &&
-	test_when_finished git notes --ref note2 remove HEAD &&
 
 	git config format.notes note1 &&
 	git format-patch -1 --stdout >out &&
@@ -2516,6 +2516,21 @@ test_expect_success 'range-diff: solo-patch' '
 	test_cmp expect actual
 '
 
+test_expect_success 'interdiff: multi-patch, implicit --cover-letter' '
+	test_when_finished "rm -f v23-0*.patch" &&
+	git format-patch --interdiff=boop~2 -2 -v23 &&
+	test_grep "^Interdiff against v22:$" v23-0000-cover-letter.patch &&
+	test_cmp expect actual
+'
+
+test_expect_success 'interdiff: explicit --no-cover-letter defeats implied --cover-letter' '
+	test_when_finished "rm -f v23-0*.patch" &&
+	test_must_fail git format-patch --no-cover-letter \
+		--interdiff=boop~2 -2 -v23 &&
+	test_must_fail git -c format.coverLetter=no format-patch \
+		--interdiff=boop~2 -2 -v23
+'
+
 test_expect_success 'format-patch does not respect diff.noprefix' '
 	git -c diff.noprefix format-patch -1 --stdout >actual &&
 	grep "^--- a/blorp" actual