format-patch: introduce --base=auto option

diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
index edf07eefd4d7f5508547a835955adfdb8fb59373..1bfd868f6d2902dd501f7bca210fd00a7fc9174a 100755 (executable)
--- a/t/t4014-format-patch.sh
+++ b/t/t4014-format-patch.sh
@@ -1507,4 +1507,43 @@ test_expect_success 'format-patch --base errors out when base commit is not ance
        test_cmp expected actual
 '
 
+test_expect_success 'format-patch --base=auto' '
+       git checkout -b upstream master &&
+       git checkout -b local upstream &&
+       git branch --set-upstream-to=upstream &&
+       test_commit N1 &&
+       test_commit N2 &&
+       git format-patch --stdout --base=auto -2 >patch &&
+       grep "^base-commit:" patch >actual &&
+       echo "base-commit: $(git rev-parse upstream)" >expected &&
+       test_cmp expected actual
+'
+
+test_expect_success 'format-patch errors out when history involves criss-cross' '
+       # setup criss-cross history
+       #
+       #   B---M1---D
+       #  / \ /
+       # A   X
+       #  \ / \
+       #   C---M2---E
+       #
+       git checkout master &&
+       test_commit A &&
+       git checkout -b xb master &&
+       test_commit B &&
+       git checkout -b xc master &&
+       test_commit C &&
+       git checkout -b xbc xb -- &&
+       git merge xc &&
+       git checkout -b xcb xc -- &&
+       git branch --set-upstream-to=xbc &&
+       git merge xb &&
+       git checkout xbc &&
+       test_commit D &&
+       git checkout xcb &&
+       test_commit E &&
+       test_must_fail  git format-patch --base=auto -1
+'
+
 test_done