merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 201 insertions, 65 deletions

diff --git a/third_party/git/t/t1400-update-ref.sh b/third_party/git/t/t1400-update-ref.sh
index 1fbd940408..770e7be363 100755
--- a/third_party/git/t/t1400-update-ref.sh
+++ b/third_party/git/t/t1400-update-ref.sh
@@ -37,15 +37,15 @@ test_expect_success setup '
 
 test_expect_success "create $m" '
 	git update-ref $m $A &&
-	test $A = $(cat .git/$m)
+	test $A = $(git show-ref -s --verify $m)
 '
 test_expect_success "create $m with oldvalue verification" '
 	git update-ref $m $B $A &&
-	test $B = $(cat .git/$m)
+	test $B = $(git show-ref -s --verify $m)
 '
 test_expect_success "fail to delete $m with stale ref" '
 	test_must_fail git update-ref -d $m $A &&
-	test $B = "$(cat .git/$m)"
+	test $B = "$(git show-ref -s --verify $m)"
 '
 test_expect_success "delete $m" '
 	test_when_finished "rm -f .git/$m" &&
@@ -56,7 +56,7 @@ test_expect_success "delete $m" '
 test_expect_success "delete $m without oldvalue verification" '
 	test_when_finished "rm -f .git/$m" &&
 	git update-ref $m $A &&
-	test $A = $(cat .git/$m) &&
+	test $A = $(git show-ref -s --verify $m) &&
 	git update-ref -d $m &&
 	test_path_is_missing .git/$m
 '
@@ -69,15 +69,15 @@ test_expect_success "fail to create $n" '
 
 test_expect_success "create $m (by HEAD)" '
 	git update-ref HEAD $A &&
-	test $A = $(cat .git/$m)
+	test $A = $(git show-ref -s --verify $m)
 '
 test_expect_success "create $m (by HEAD) with oldvalue verification" '
 	git update-ref HEAD $B $A &&
-	test $B = $(cat .git/$m)
+	test $B = $(git show-ref -s --verify $m)
 '
 test_expect_success "fail to delete $m (by HEAD) with stale ref" '
 	test_must_fail git update-ref -d HEAD $A &&
-	test $B = $(cat .git/$m)
+	test $B = $(git show-ref -s --verify $m)
 '
 test_expect_success "delete $m (by HEAD)" '
 	test_when_finished "rm -f .git/$m" &&
@@ -160,10 +160,10 @@ test_expect_success 'core.logAllRefUpdates=always creates reflog by default' '
 	git reflog exists $outside
 '
 
-test_expect_success 'core.logAllRefUpdates=always creates no reflog for ORIG_HEAD' '
+test_expect_success 'core.logAllRefUpdates=always creates reflog for ORIG_HEAD' '
 	test_config core.logAllRefUpdates always &&
 	git update-ref ORIG_HEAD $A &&
-	test_must_fail git reflog exists ORIG_HEAD
+	git reflog exists ORIG_HEAD
 '
 
 test_expect_success '--no-create-reflog overrides core.logAllRefUpdates=always' '
@@ -178,14 +178,14 @@ test_expect_success '--no-create-reflog overrides core.logAllRefUpdates=always'
 
 test_expect_success "create $m (by HEAD)" '
 	git update-ref HEAD $A &&
-	test $A = $(cat .git/$m)
+	test $A = $(git show-ref -s --verify $m)
 '
 test_expect_success 'pack refs' '
 	git pack-refs --all
 '
 test_expect_success "move $m (by HEAD)" '
 	git update-ref HEAD $B $A &&
-	test $B = $(cat .git/$m)
+	test $B = $(git show-ref -s --verify $m)
 '
 test_expect_success "delete $m (by HEAD) should remove both packed and loose $m" '
 	test_when_finished "rm -f .git/$m" &&
@@ -255,7 +255,7 @@ test_expect_success '(not) change HEAD with wrong SHA1' '
 '
 test_expect_success "(not) changed .git/$m" '
 	test_when_finished "rm -f .git/$m" &&
-	! test $B = $(cat .git/$m)
+	! test $B = $(git show-ref -s --verify $m)
 '
 
 rm -f .git/logs/refs/heads/master
@@ -263,19 +263,19 @@ test_expect_success "create $m (logged by touch)" '
 	test_config core.logAllRefUpdates false &&
 	GIT_COMMITTER_DATE="2005-05-26 23:30" \
 	git update-ref --create-reflog HEAD $A -m "Initial Creation" &&
-	test $A = $(cat .git/$m)
+	test $A = $(git show-ref -s --verify $m)
 '
 test_expect_success "update $m (logged by touch)" '
 	test_config core.logAllRefUpdates false &&
 	GIT_COMMITTER_DATE="2005-05-26 23:31" \
 	git update-ref HEAD $B $A -m "Switch" &&
-	test $B = $(cat .git/$m)
+	test $B = $(git show-ref -s --verify $m)
 '
 test_expect_success "set $m (logged by touch)" '
 	test_config core.logAllRefUpdates false &&
 	GIT_COMMITTER_DATE="2005-05-26 23:41" \
 	git update-ref HEAD $A &&
-	test $A = $(cat .git/$m)
+	test $A = $(git show-ref -s --verify $m)
 '
 
 test_expect_success 'empty directory removal' '
@@ -319,19 +319,19 @@ test_expect_success "create $m (logged by config)" '
 	test_config core.logAllRefUpdates true &&
 	GIT_COMMITTER_DATE="2005-05-26 23:32" \
 	git update-ref HEAD $A -m "Initial Creation" &&
-	test $A = $(cat .git/$m)
+	test $A = $(git show-ref -s --verify $m)
 '
 test_expect_success "update $m (logged by config)" '
 	test_config core.logAllRefUpdates true &&
 	GIT_COMMITTER_DATE="2005-05-26 23:33" \
-	git update-ref HEAD'" $B $A "'-m "Switch" &&
-	test $B = $(cat .git/$m)
+	git update-ref HEAD $B $A -m "Switch" &&
+	test $B = $(git show-ref -s --verify $m)
 '
 test_expect_success "set $m (logged by config)" '
 	test_config core.logAllRefUpdates true &&
 	GIT_COMMITTER_DATE="2005-05-26 23:43" \
 	git update-ref HEAD $A &&
-	test $A = $(cat .git/$m)
+	test $A = $(git show-ref -s --verify $m)
 '
 
 cat >expect <<EOF
@@ -344,14 +344,16 @@ test_expect_success "verifying $m's log (logged by config)" '
 	test_cmp expect .git/logs/$m
 '
 
-git update-ref $m $D
-cat >.git/logs/$m <<EOF
-$Z $C $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150320 -0500
-$C $A $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150350 -0500
-$A $B $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150380 -0500
-$F $Z $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150680 -0500
-$Z $E $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150980 -0500
-EOF
+test_expect_success 'set up for querying the reflog' '
+	git update-ref $m $D &&
+	cat >.git/logs/$m <<-EOF
+	$Z $C $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150320 -0500
+	$C $A $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150350 -0500
+	$A $B $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150380 -0500
+	$F $Z $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150680 -0500
+	$Z $E $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150980 -0500
+	EOF
+'
 
 ed="Thu, 26 May 2005 18:32:00 -0500"
 gd="Thu, 26 May 2005 18:33:00 -0500"
@@ -359,55 +361,67 @@ ld="Thu, 26 May 2005 18:43:00 -0500"
 test_expect_success 'Query "master@{May 25 2005}" (before history)' '
 	test_when_finished "rm -f o e" &&
 	git rev-parse --verify "master@{May 25 2005}" >o 2>e &&
-	test $C = $(cat o) &&
-	test "warning: Log for '\''master'\'' only goes back to $ed." = "$(cat e)"
+	echo "$C" >expect &&
+	test_cmp expect o &&
+	echo "warning: log for '\''master'\'' only goes back to $ed" >expect &&
+	test_i18ncmp expect e
 '
 test_expect_success 'Query master@{2005-05-25} (before history)' '
 	test_when_finished "rm -f o e" &&
 	git rev-parse --verify master@{2005-05-25} >o 2>e &&
-	test $C = $(cat o) &&
-	test "warning: Log for '\''master'\'' only goes back to $ed." = "$(cat e)"
+	echo "$C" >expect &&
+	test_cmp expect o &&
+	echo "warning: log for '\''master'\'' only goes back to $ed" >expect &&
+	test_i18ncmp expect e
 '
 test_expect_success 'Query "master@{May 26 2005 23:31:59}" (1 second before history)' '
 	test_when_finished "rm -f o e" &&
 	git rev-parse --verify "master@{May 26 2005 23:31:59}" >o 2>e &&
-	test $C = $(cat o) &&
-	test "warning: Log for '\''master'\'' only goes back to $ed." = "$(cat e)"
+	echo "$C" >expect &&
+	test_cmp expect o &&
+	echo "warning: log for '\''master'\'' only goes back to $ed" >expect &&
+	test_i18ncmp expect e
 '
 test_expect_success 'Query "master@{May 26 2005 23:32:00}" (exactly history start)' '
 	test_when_finished "rm -f o e" &&
 	git rev-parse --verify "master@{May 26 2005 23:32:00}" >o 2>e &&
-	test $C = $(cat o) &&
-	test "" = "$(cat e)"
+	echo "$C" >expect &&
+	test_cmp expect o &&
+	test_must_be_empty e
 '
 test_expect_success 'Query "master@{May 26 2005 23:32:30}" (first non-creation change)' '
 	test_when_finished "rm -f o e" &&
 	git rev-parse --verify "master@{May 26 2005 23:32:30}" >o 2>e &&
-	test $A = $(cat o) &&
-	test "" = "$(cat e)"
+	echo "$A" >expect &&
+	test_cmp expect o &&
+	test_must_be_empty e
 '
 test_expect_success 'Query "master@{2005-05-26 23:33:01}" (middle of history with gap)' '
 	test_when_finished "rm -f o e" &&
 	git rev-parse --verify "master@{2005-05-26 23:33:01}" >o 2>e &&
-	test $B = $(cat o) &&
+	echo "$B" >expect &&
+	test_cmp expect o &&
 	test_i18ngrep -F "warning: log for ref $m has gap after $gd" e
 '
 test_expect_success 'Query "master@{2005-05-26 23:38:00}" (middle of history)' '
 	test_when_finished "rm -f o e" &&
 	git rev-parse --verify "master@{2005-05-26 23:38:00}" >o 2>e &&
-	test $Z = $(cat o) &&
-	test "" = "$(cat e)"
+	echo "$Z" >expect &&
+	test_cmp expect o &&
+	test_must_be_empty e
 '
 test_expect_success 'Query "master@{2005-05-26 23:43:00}" (exact end of history)' '
 	test_when_finished "rm -f o e" &&
 	git rev-parse --verify "master@{2005-05-26 23:43:00}" >o 2>e &&
-	test $E = $(cat o) &&
-	test "" = "$(cat e)"
+	echo "$E" >expect &&
+	test_cmp expect o &&
+	test_must_be_empty e
 '
 test_expect_success 'Query "master@{2005-05-28}" (past end of history)' '
 	test_when_finished "rm -f o e" &&
 	git rev-parse --verify "master@{2005-05-28}" >o 2>e &&
-	test $D = $(cat o) &&
+	echo "$D" >expect &&
+	test_cmp expect o &&
 	test_i18ngrep -F "warning: log for ref $m unexpectedly ended on $ld" e
 '
 
@@ -461,57 +475,57 @@ test_expect_success 'git cat-file blob master@{2005-05-26 23:42}:F (expect OTHER
 
 test_expect_success 'given old value for missing pseudoref, do not create' '
 	test_must_fail git update-ref PSEUDOREF $A $B 2>err &&
-	test_path_is_missing .git/PSEUDOREF &&
-	test_i18ngrep "could not read ref" err
+	test_must_fail git rev-parse PSEUDOREF &&
+	test_i18ngrep "unable to resolve reference" err
 '
 
 test_expect_success 'create pseudoref' '
 	git update-ref PSEUDOREF $A &&
-	test $A = $(cat .git/PSEUDOREF)
+	test $A = $(git rev-parse PSEUDOREF)
 '
 
 test_expect_success 'overwrite pseudoref with no old value given' '
 	git update-ref PSEUDOREF $B &&
-	test $B = $(cat .git/PSEUDOREF)
+	test $B = $(git rev-parse PSEUDOREF)
 '
 
 test_expect_success 'overwrite pseudoref with correct old value' '
 	git update-ref PSEUDOREF $C $B &&
-	test $C = $(cat .git/PSEUDOREF)
+	test $C = $(git rev-parse PSEUDOREF)
 '
 
 test_expect_success 'do not overwrite pseudoref with wrong old value' '
 	test_must_fail git update-ref PSEUDOREF $D $E 2>err &&
-	test $C = $(cat .git/PSEUDOREF) &&
-	test_i18ngrep "unexpected object ID" err
+	test $C = $(git rev-parse PSEUDOREF) &&
+	test_i18ngrep "cannot lock ref.*expected" err
 '
 
 test_expect_success 'delete pseudoref' '
 	git update-ref -d PSEUDOREF &&
-	test_path_is_missing .git/PSEUDOREF
+	test_must_fail git rev-parse PSEUDOREF
 '
 
 test_expect_success 'do not delete pseudoref with wrong old value' '
 	git update-ref PSEUDOREF $A &&
 	test_must_fail git update-ref -d PSEUDOREF $B 2>err &&
-	test $A = $(cat .git/PSEUDOREF) &&
-	test_i18ngrep "unexpected object ID" err
+	test $A = $(git rev-parse PSEUDOREF) &&
+	test_i18ngrep "cannot lock ref.*expected" err
 '
 
 test_expect_success 'delete pseudoref with correct old value' '
 	git update-ref -d PSEUDOREF $A &&
-	test_path_is_missing .git/PSEUDOREF
+	test_must_fail git rev-parse PSEUDOREF
 '
 
 test_expect_success 'create pseudoref with old OID zero' '
 	git update-ref PSEUDOREF $A $Z &&
-	test $A = $(cat .git/PSEUDOREF)
+	test $A = $(git rev-parse PSEUDOREF)
 '
 
 test_expect_success 'do not overwrite pseudoref with old OID zero' '
 	test_when_finished git update-ref -d PSEUDOREF &&
 	test_must_fail git update-ref PSEUDOREF $B $Z 2>err &&
-	test $A = $(cat .git/PSEUDOREF) &&
+	test $A = $(git rev-parse PSEUDOREF) &&
 	test_i18ngrep "already exists" err
 '
 
@@ -1340,15 +1354,6 @@ test_expect_success 'fails with duplicate ref update via symref' '
 	test_cmp expect actual
 '
 
-run_with_limited_open_files () {
-	(ulimit -n 32 && "$@")
-}
-
-test_lazy_prereq ULIMIT_FILE_DESCRIPTORS '
-	test_have_prereq !MINGW,!CYGWIN &&
-	run_with_limited_open_files true
-'
-
 test_expect_success ULIMIT_FILE_DESCRIPTORS 'large transaction creating branches does not burst open file limit' '
 (
 	for i in $(test_seq 33)
@@ -1390,4 +1395,135 @@ test_expect_success 'handle per-worktree refs in refs/bisect' '
 	! test_cmp main-head worktree-head
 '
 
+test_expect_success 'transaction handles empty commit' '
+	cat >stdin <<-EOF &&
+	start
+	prepare
+	commit
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start prepare commit >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction handles empty commit with missing prepare' '
+	cat >stdin <<-EOF &&
+	start
+	commit
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start commit >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction handles sole commit' '
+	cat >stdin <<-EOF &&
+	commit
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" commit >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction handles empty abort' '
+	cat >stdin <<-EOF &&
+	start
+	prepare
+	abort
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start prepare abort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction exits on multiple aborts' '
+	cat >stdin <<-EOF &&
+	abort
+	abort
+	EOF
+	test_must_fail git update-ref --stdin <stdin >actual 2>err &&
+	printf "%s: ok\n" abort >expect &&
+	test_cmp expect actual &&
+	grep "fatal: transaction is closed" err
+'
+
+test_expect_success 'transaction exits on start after prepare' '
+	cat >stdin <<-EOF &&
+	prepare
+	start
+	EOF
+	test_must_fail git update-ref --stdin <stdin 2>err >actual &&
+	printf "%s: ok\n" prepare >expect &&
+	test_cmp expect actual &&
+	grep "fatal: prepared transactions can only be closed" err
+'
+
+test_expect_success 'transaction handles empty abort with missing prepare' '
+	cat >stdin <<-EOF &&
+	start
+	abort
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start abort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction handles sole abort' '
+	cat >stdin <<-EOF &&
+	abort
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" abort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction can handle commit' '
+	cat >stdin <<-EOF &&
+	start
+	create $a HEAD
+	commit
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start commit >expect &&
+	test_cmp expect actual &&
+	git rev-parse HEAD >expect &&
+	git rev-parse $a >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'transaction can handle abort' '
+	cat >stdin <<-EOF &&
+	start
+	create $b HEAD
+	abort
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start abort >expect &&
+	test_cmp expect actual &&
+	test_path_is_missing .git/$b
+'
+
+test_expect_success 'transaction aborts by default' '
+	cat >stdin <<-EOF &&
+	start
+	create $b HEAD
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start >expect &&
+	test_cmp expect actual &&
+	test_path_is_missing .git/$b
+'
+
+test_expect_success 'transaction with prepare aborts by default' '
+	cat >stdin <<-EOF &&
+	start
+	create $b HEAD
+	prepare
+	EOF
+	git update-ref --stdin <stdin >actual &&
+	printf "%s: ok\n" start prepare >expect &&
+	test_cmp expect actual &&
+	test_path_is_missing .git/$b
+'
+
 test_done