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>
This commit is contained in:
Elijah Newren 2021-07-21 01:42:17 +00:00 коммит произвёл Junio C Hamano
Родитель 75ae10bc75
Коммит be19c5ca3e
1 изменённых файлов: 182 добавлений и 0 удалений

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@ -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 &&