t7601: test interaction of merge/rebase/fast-forward flags and options
The interaction of rebase and merge flags and options was not well tested. Add several tests to check for correct behavior from the following rules: * --ff-only vs. --[no-]rebase (and the related pull.ff=only vs. pull.rebase) * --rebase[=!false] vs. --no-ff and --ff (and the related pull.rebase=!false overrides pull.ff=!only) * command line flags take precedence over config, except: * --no-rebase heeds pull.ff=!only * pull.rebase=!false vs --no-ff and --ff For more details behind these rules and a larger table of individual cases, refer to https://lore.kernel.org/git/xmqqwnpqot4m.fsf@gitster.g/ and the links found therein. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren committed
Jul 21, 2021 at 01:42 UTC
be19c5ca3e28cb16d55623de2e5aa1d45bd5b5ba
1 file changed
+182
t/t7601-merge-pull-config.sh
+182
index 52e8ccc933..a44e6e69f2 100755
--- a/t/t7601-merge-pull-config.sh
+++ b/t/t7601-merge-pull-config.sh
@@ -143,6 +143,188 @@ test_expect_success 'pull.rebase not set and --ff-only given (not-fast-forward)'
test_i18ngrep ! "Pulling without specifying how to reconcile" err
'
+test_does_rebase () {
+ git reset --hard c2 &&
+ git "$@" . c1 &&
+ # Check that we actually did a rebase
+ git rev-list --count HEAD >actual &&
+ git rev-list --merges --count HEAD >>actual &&
+ test_write_lines 3 0 >expect &&
+ test_cmp expect actual &&
+ rm actual expect
+}
+
+# Prefers merge over fast-forward
+test_does_merge_when_ff_possible () {
+ git reset --hard c0 &&
+ git "$@" . c1 &&
+ # Check that we actually did a merge
+ git rev-list --count HEAD >actual &&
+ git rev-list --merges --count HEAD >>actual &&
+ test_write_lines 3 1 >expect &&
+ test_cmp expect actual &&
+ rm actual expect
+}
+
+# Prefers fast-forward over merge or rebase
+test_does_fast_forward () {
+ git reset --hard c0 &&
+ git "$@" . c1 &&
+
+ # Check that we did not get any merges
+ git rev-list --count HEAD >actual &&
+ git rev-list --merges --count HEAD >>actual &&
+ test_write_lines 2 0 >expect &&
+ test_cmp expect actual &&
+
+ # Check that we ended up at c1
+ git rev-parse HEAD >actual &&
+ git rev-parse c1^{commit} >expect &&
+ test_cmp actual expect &&
+
+ # Remove temporary files
+ rm actual expect
+}
+
+# Doesn't fail when fast-forward not possible; does a merge
+test_falls_back_to_full_merge () {
+ git reset --hard c2 &&
+ git "$@" . c1 &&
+ # Check that we actually did a merge
+ git rev-list --count HEAD >actual &&
+ git rev-list --merges --count HEAD >>actual &&
+ test_write_lines 4 1 >expect &&
+ test_cmp expect actual &&
+ rm actual expect
+}
+
+# Attempts fast forward, which is impossible, and bails
+test_attempts_fast_forward () {
+ git reset --hard c2 &&
+ test_must_fail git "$@" . c1 2>err &&
+ test_i18ngrep "Not possible to fast-forward, aborting" err
+}
+
+#
+# Group 1: Interaction of --ff-only with --[no-]rebase
+# (And related interaction of pull.ff=only with pull.rebase)
+#
+test_expect_failure '--ff-only overrides --rebase' '
+ test_attempts_fast_forward pull --rebase --ff-only
+'
+
+test_expect_failure '--ff-only overrides --rebase even if first' '
+ test_attempts_fast_forward pull --ff-only --rebase
+'
+
+test_expect_success '--ff-only overrides --no-rebase' '
+ test_attempts_fast_forward pull --ff-only --no-rebase
+'
+
+test_expect_failure 'pull.ff=only overrides pull.rebase=true' '
+ test_attempts_fast_forward -c pull.ff=only -c pull.rebase=true pull
+'
+
+test_expect_success 'pull.ff=only overrides pull.rebase=false' '
+ test_attempts_fast_forward -c pull.ff=only -c pull.rebase=false pull
+'
+
+# Group 2: --rebase=[!false] overrides --no-ff and --ff
+# (And related interaction of pull.rebase=!false and pull.ff=!only)
+test_expect_success '--rebase overrides --no-ff' '
+ test_does_rebase pull --rebase --no-ff
+'
+
+test_expect_success '--rebase overrides --ff' '
+ test_does_rebase pull --rebase --ff
+'
+
+test_expect_success '--rebase fast-forwards when possible' '
+ test_does_fast_forward pull --rebase --ff
+'
+
+test_expect_success 'pull.rebase=true overrides pull.ff=false' '
+ test_does_rebase -c pull.rebase=true -c pull.ff=false pull
+'
+
+test_expect_success 'pull.rebase=true overrides pull.ff=true' '
+ test_does_rebase -c pull.rebase=true -c pull.ff=true pull
+'
+
+# Group 3: command line flags take precedence over config
+test_expect_failure '--ff-only takes precedence over pull.rebase=true' '
+ test_attempts_fast_forward -c pull.rebase=true pull --ff-only
+'
+
+test_expect_success '--ff-only takes precedence over pull.rebase=false' '
+ test_attempts_fast_forward -c pull.rebase=false pull --ff-only
+'
+
+test_expect_failure '--no-rebase takes precedence over pull.ff=only' '
+ test_falls_back_to_full_merge -c pull.ff=only pull --no-rebase
+'
+
+test_expect_success '--rebase takes precedence over pull.ff=only' '
+ test_does_rebase -c pull.ff=only pull --rebase
+'
+
+test_expect_success '--rebase overrides pull.ff=true' '
+ test_does_rebase -c pull.ff=true pull --rebase
+'
+
+test_expect_success '--rebase overrides pull.ff=false' '
+ test_does_rebase -c pull.ff=false pull --rebase
+'
+
+test_expect_success '--rebase overrides pull.ff unset' '
+ test_does_rebase pull --rebase
+'
+
+# Group 4: --no-rebase heeds pull.ff=!only or explict --ff or --no-ff
+
+test_expect_success '--no-rebase works with --no-ff' '
+ test_does_merge_when_ff_possible pull --no-rebase --no-ff
+'
+
+test_expect_success '--no-rebase works with --ff' '
+ test_does_fast_forward pull --no-rebase --ff
+'
+
+test_expect_success '--no-rebase does ff if pull.ff unset' '
+ test_does_fast_forward pull --no-rebase
+'
+
+test_expect_success '--no-rebase heeds pull.ff=true' '
+ test_does_fast_forward -c pull.ff=true pull --no-rebase
+'
+
+test_expect_success '--no-rebase heeds pull.ff=false' '
+ test_does_merge_when_ff_possible -c pull.ff=false pull --no-rebase
+'
+
+# Group 5: pull.rebase=!false in combination with --no-ff or --ff
+test_expect_success 'pull.rebase=true and --no-ff' '
+ test_does_rebase -c pull.rebase=true pull --no-ff
+'
+
+test_expect_success 'pull.rebase=true and --ff' '
+ test_does_rebase -c pull.rebase=true pull --ff
+'
+
+test_expect_success 'pull.rebase=false and --no-ff' '
+ test_does_merge_when_ff_possible -c pull.rebase=false pull --no-ff
+'
+
+test_expect_success 'pull.rebase=false and --ff, ff possible' '
+ test_does_fast_forward -c pull.rebase=false pull --ff
+'
+
+test_expect_success 'pull.rebase=false and --ff, ff not possible' '
+ test_falls_back_to_full_merge -c pull.rebase=false pull --ff
+'
+
+# End of groupings for conflicting merge vs. rebase flags/options
+
test_expect_success 'merge c1 with c2' '
git reset --hard c1 &&
test -f c0.c &&