From: Karthik Nayak <karthik.188@xxxxxxxxx>
The revision backend is used by multiple porcelain commands such as
git-rev-list(1) and git-log(1). The backend currently supports ignoring
missing links by setting the `ignore_missing_links` bit. This allows the
revision walk to skip any objects links which are missing. Expose this
bit via an `--ignore-missing-links` user option.
A scenario where this option would be used is to find the boundary
objects between different object directories. Consider a repository with
a main object directory (GIT_OBJECT_DIRECTORY) and one or more alternate
object directories (GIT_ALTERNATE_OBJECT_DIRECTORIES). In such a
repository, enabling this option along with the `--boundary` option
while disabling the alternate object directory allows us to find the
boundary objects between the main and alternate object directory.
Helped-by: Taylor Blau <me@xxxxxxxxxxxx>
Signed-off-by: Karthik Nayak <karthik.188@xxxxxxxxx>
---
Changes since v2:
- Refactored the tests thanks to Taylor!
Range diff against version 2:
1: e3f4d85732 ! 1: a08f3637a0 revision: add `--ignore-missing-links` user option
@@ Commit message
while disabling the alternate object directory allows us to find the
boundary objects between the main and alternate object directory.
+ Helped-by: Taylor Blau <me@xxxxxxxxxxxx>
Signed-off-by: Karthik Nayak <karthik.188@xxxxxxxxx>
## Documentation/rev-list-options.txt ##
@@ t/t6022-rev-list-alternates.sh (new)
+# We create 5 commits and move them to the alt directory and
+# create 5 more commits which will stay in the main odb.
+test_expect_success 'create repository and alternate directory' '
-+ git init main &&
-+ test_commit_bulk -C main 5 &&
-+ BOUNDARY_COMMIT=$(git -C main rev-parse HEAD) &&
-+ mkdir alt &&
-+ mv main/.git/objects/* alt &&
-+ GIT_ALTERNATE_OBJECT_DIRECTORIES=$PWD/alt test_commit_bulk --start=6 -C main 5
++ test_commit_bulk 5 &&
++ git clone --reference=. --shared . alt &&
++ test_commit_bulk --start=6 -C alt 5
+'
+
+# when the alternate odb is provided, all commits are listed along with the boundary
+# commit.
+test_expect_success 'rev-list passes with alternate object directory' '
-+ GIT_ALTERNATE_OBJECT_DIRECTORIES=$PWD/alt git -C main rev-list HEAD >actual &&
-+ test_stdout_line_count = 10 cat actual &&
-+ grep $BOUNDARY_COMMIT actual
++ git -C alt rev-list --all --objects --no-object-names >actual.raw &&
++ {
++ git rev-list --all --objects --no-object-names &&
++ git -C alt rev-list --all --objects --no-object-names --not \
++ --alternate-refs
++ } >expect.raw &&
++ sort actual.raw >actual &&
++ sort expect.raw >expect &&
++ test_cmp expect actual
+'
+
++alt=alt/.git/objects/info/alternates
++
++hide_alternates () {
++ test -f "$alt.bak" || mv "$alt" "$alt.bak"
++}
++
++show_alternates () {
++ test -f "$alt" || mv "$alt.bak" "$alt"
++}
++
+# When the alternate odb is not provided, rev-list fails since the 5th commit's
+# parent is not present in the main odb.
+test_expect_success 'rev-list fails without alternate object directory' '
-+ test_must_fail git -C main rev-list HEAD
++ hide_alternates &&
++ test_must_fail git -C alt rev-list HEAD
+'
+
+# With `--ignore-missing-links`, we stop the traversal when we encounter a
+# missing link. The boundary commit is not listed as we haven't used the
+# `--boundary` options.
+test_expect_success 'rev-list only prints main odb commits with --ignore-missing-links' '
-+ git -C main rev-list --ignore-missing-links HEAD >actual &&
-+ test_stdout_line_count = 5 cat actual &&
-+ ! grep -$BOUNDARY_COMMIT actual
++ hide_alternates &&
++
++ git -C alt rev-list --objects --no-object-names \
++ --ignore-missing-links HEAD >actual.raw &&
++ git -C alt cat-file --batch-check="%(objectname)" \
++ --batch-all-objects >expect.raw &&
++
++ sort actual.raw >actual &&
++ sort expect.raw >expect &&
++ test_must_fail git -C alt rev-list HEAD
+'
+
+# With `--ignore-missing-links` and `--boundary`, we can even print those boundary
+# commits.
+test_expect_success 'rev-list prints boundary commit with --ignore-missing-links' '
-+ git -C main rev-list --ignore-missing-links --boundary HEAD >actual &&
-+ test_stdout_line_count = 6 cat actual &&
-+ grep -$BOUNDARY_COMMIT actual
++ git -C alt rev-list --ignore-missing-links --boundary HEAD >got &&
++ grep "^-$(git rev-parse HEAD)" got
+'
+
-+# The `--ignore-missing-links` option should ensure that git-rev-list(1) doesn't
-+# fail when used alongside `--objects` when a tree is missing.
-+test_expect_success 'rev-list --ignore-missing-links works with missing tree' '
-+ echo "foo" >main/file &&
-+ git -C main add file &&
-+ GIT_ALTERNATE_OBJECT_DIRECTORIES=$PWD/alt git -C main commit -m"commit 11" &&
-+ TREE_OID=$(git -C main rev-parse HEAD^{tree}) &&
-+ mkdir alt/${TREE_OID:0:2} &&
-+ mv main/.git/objects/${TREE_OID:0:2}/${TREE_OID:2} alt/${TREE_OID:0:2}/ &&
-+ git -C main rev-list --ignore-missing-links --objects HEAD >actual &&
-+ ! grep $TREE_OID actual
++test_expect_success "setup for rev-list --ignore-missing-links with missing objects" '
++ show_alternates &&
++ test_commit -C alt 11
+'
+
-+# Similar to above, it should also work when a blob is missing.
-+test_expect_success 'rev-list --ignore-missing-links works with missing blob' '
-+ echo "bar" >main/file &&
-+ git -C main add file &&
-+ GIT_ALTERNATE_OBJECT_DIRECTORIES=$PWD/alt git -C main commit -m"commit 12" &&
-+ BLOB_OID=$(git -C main rev-parse HEAD:file) &&
-+ mkdir alt/${BLOB_OID:0:2} &&
-+ mv main/.git/objects/${BLOB_OID:0:2}/${BLOB_OID:2} alt/${BLOB_OID:0:2}/ &&
-+ git -C main rev-list --ignore-missing-links --objects HEAD >actual &&
-+ ! grep $BLOB_OID actual
-+'
++for obj in "HEAD^{tree}" "HEAD:11.t"
++do
++ # The `--ignore-missing-links` option should ensure that git-rev-list(1)
++ # doesn't fail when used alongside `--objects` when a tree/blob is
++ # missing.
++ test_expect_success "rev-list --ignore-missing-links with missing $type" '
++ oid="$(git -C alt rev-parse $obj)" &&
++ path="alt/.git/objects/$(test_oid_to_path $oid)" &&
++
++ mv "$path" "$path.hidden" &&
++ test_when_finished "mv $path.hidden $path" &&
++
++ git -C alt rev-list --ignore-missing-links --objects HEAD \
++ >actual &&
++ ! grep $oid actual
++ '
++done
+
+test_done
Documentation/rev-list-options.txt | 9 +++
builtin/rev-list.c | 3 +-
revision.c | 2 +
t/t6022-rev-list-alternates.sh | 93 ++++++++++++++++++++++++++++++
4 files changed, 106 insertions(+), 1 deletion(-)
create mode 100755 t/t6022-rev-list-alternates.sh
diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index a4a0cb93b2..8ee713db3d 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -227,6 +227,15 @@ explicitly.
Upon seeing an invalid object name in the input, pretend as if
the bad input was not given.
+--ignore-missing-links::
+ During traversal, if an object that is referenced does not
+ exist, instead of dying of a repository corruption, pretend as
+ if the reference itself does not exist. Running the command
+ with the `--boundary` option makes these missing commits,
+ together with the commits on the edge of revision ranges
+ (i.e. true boundary objects), appear on the output, prefixed
+ with '-'.
+
ifndef::git-rev-list[]
--bisect::
Pretend as if the bad bisection ref `refs/bisect/bad`
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index ff715d6918..5239d83c76 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -266,7 +266,8 @@ static int finish_object(struct object *obj, const char *name UNUSED,
{
struct rev_list_info *info = cb_data;
if (oid_object_info_extended(the_repository, &obj->oid, NULL, 0) < 0) {
- finish_object__ma(obj);
+ if (!info->revs->ignore_missing_links)
+ finish_object__ma(obj);
return 1;
}
if (info->revs->verify_objects && !obj->parsed && obj->type != OBJ_COMMIT)
diff --git a/revision.c b/revision.c
index 2f4c53ea20..cbfcbf6e28 100644
--- a/revision.c
+++ b/revision.c
@@ -2595,6 +2595,8 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
revs->limited = 1;
} else if (!strcmp(arg, "--ignore-missing")) {
revs->ignore_missing = 1;
+ } else if (!strcmp(arg, "--ignore-missing-links")) {
+ revs->ignore_missing_links = 1;
} else if (opt && opt->allow_exclude_promisor_objects &&
!strcmp(arg, "--exclude-promisor-objects")) {
if (fetch_if_missing)
diff --git a/t/t6022-rev-list-alternates.sh b/t/t6022-rev-list-alternates.sh
new file mode 100755
index 0000000000..567dd21876
--- /dev/null
+++ b/t/t6022-rev-list-alternates.sh
@@ -0,0 +1,93 @@
+#!/bin/sh
+
+test_description='handling of alternates in rev-list'
+
+TEST_PASSES_SANITIZE_LEAK=true
+. ./test-lib.sh
+
+# We create 5 commits and move them to the alt directory and
+# create 5 more commits which will stay in the main odb.
+test_expect_success 'create repository and alternate directory' '
+ test_commit_bulk 5 &&
+ git clone --reference=. --shared . alt &&
+ test_commit_bulk --start=6 -C alt 5
+'
+
+# when the alternate odb is provided, all commits are listed along with the boundary
+# commit.
+test_expect_success 'rev-list passes with alternate object directory' '
+ git -C alt rev-list --all --objects --no-object-names >actual.raw &&
+ {
+ git rev-list --all --objects --no-object-names &&
+ git -C alt rev-list --all --objects --no-object-names --not \
+ --alternate-refs
+ } >expect.raw &&
+ sort actual.raw >actual &&
+ sort expect.raw >expect &&
+ test_cmp expect actual
+'
+
+alt=alt/.git/objects/info/alternates
+
+hide_alternates () {
+ test -f "$alt.bak" || mv "$alt" "$alt.bak"
+}
+
+show_alternates () {
+ test -f "$alt" || mv "$alt.bak" "$alt"
+}
+
+# When the alternate odb is not provided, rev-list fails since the 5th commit's
+# parent is not present in the main odb.
+test_expect_success 'rev-list fails without alternate object directory' '
+ hide_alternates &&
+ test_must_fail git -C alt rev-list HEAD
+'
+
+# With `--ignore-missing-links`, we stop the traversal when we encounter a
+# missing link. The boundary commit is not listed as we haven't used the
+# `--boundary` options.
+test_expect_success 'rev-list only prints main odb commits with --ignore-missing-links' '
+ hide_alternates &&
+
+ git -C alt rev-list --objects --no-object-names \
+ --ignore-missing-links HEAD >actual.raw &&
+ git -C alt cat-file --batch-check="%(objectname)" \
+ --batch-all-objects >expect.raw &&
+
+ sort actual.raw >actual &&
+ sort expect.raw >expect &&
+ test_must_fail git -C alt rev-list HEAD
+'
+
+# With `--ignore-missing-links` and `--boundary`, we can even print those boundary
+# commits.
+test_expect_success 'rev-list prints boundary commit with --ignore-missing-links' '
+ git -C alt rev-list --ignore-missing-links --boundary HEAD >got &&
+ grep "^-$(git rev-parse HEAD)" got
+'
+
+test_expect_success "setup for rev-list --ignore-missing-links with missing objects" '
+ show_alternates &&
+ test_commit -C alt 11
+'
+
+for obj in "HEAD^{tree}" "HEAD:11.t"
+do
+ # The `--ignore-missing-links` option should ensure that git-rev-list(1)
+ # doesn't fail when used alongside `--objects` when a tree/blob is
+ # missing.
+ test_expect_success "rev-list --ignore-missing-links with missing $type" '
+ oid="$(git -C alt rev-parse $obj)" &&
+ path="alt/.git/objects/$(test_oid_to_path $oid)" &&
+
+ mv "$path" "$path.hidden" &&
+ test_when_finished "mv $path.hidden $path" &&
+
+ git -C alt rev-list --ignore-missing-links --objects HEAD \
+ >actual &&
+ ! grep $oid actual
+ '
+done
+
+test_done
--
2.41.0
