The `--missing` object option in rev-list currently works only with
missing blobs/trees. For missing commits the revision walker fails with
a fatal error.
Let's extend the functionality of `--missing` option to also support
commit objects. This is done by adding a new `MISSING` flag that the
revision walker sets whenever it encounters a missing tree/commit. The
revision walker will now continue the traversal and call `show_commit()`
even for missing commits. In rev-list we can then check for this flag
and call the existing code for parsing `--missing` objects.
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, using the `--missing=print` option while disabling the
alternate object directory allows us to find the boundary objects
between the main and alternate object directory.
Signed-off-by: Karthik Nayak <karthik.188@xxxxxxxxx>
---
builtin/rev-list.c | 6 +++
object.h | 2 +-
revision.c | 9 ++++-
revision.h | 3 ++
t/t6022-rev-list-missing.sh | 74 +++++++++++++++++++++++++++++++++++++
5 files changed, 91 insertions(+), 3 deletions(-)
create mode 100755 t/t6022-rev-list-missing.sh
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index 98542e8b3c..604ae01d0c 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -149,6 +149,12 @@ static void show_commit(struct commit *commit, void *data)
display_progress(progress, ++progress_counter);
+ if (revs->do_not_die_on_missing_objects &&
+ commit->object.flags & MISSING) {
+ finish_object__ma(&commit->object);
+ return;
+ }
+
if (show_disk_usage)
total_disk_usage += get_object_disk_usage(&commit->object);
diff --git a/object.h b/object.h
index 114d45954d..12913e6116 100644
--- a/object.h
+++ b/object.h
@@ -62,7 +62,7 @@ void object_array_init(struct object_array *array);
/*
* object flag allocation:
- * revision.h: 0---------10 15 23------27
+ * revision.h: 0---------10 15 22------27
* fetch-pack.c: 01 67
* negotiator/default.c: 2--5
* walker.c: 0-2
diff --git a/revision.c b/revision.c
index e789834dd1..615645d3d1 100644
--- a/revision.c
+++ b/revision.c
@@ -1168,7 +1168,8 @@ static int process_parents(struct rev_info *revs, struct commit *commit,
for (parent = commit->parents; parent; parent = parent->next) {
struct commit *p = parent->item;
int gently = revs->ignore_missing_links ||
- revs->exclude_promisor_objects;
+ revs->exclude_promisor_objects ||
+ revs->do_not_die_on_missing_objects;
if (repo_parse_commit_gently(revs->repo, p, gently) < 0) {
if (revs->exclude_promisor_objects &&
is_promisor_object(&p->object.oid)) {
@@ -1176,7 +1177,11 @@ static int process_parents(struct rev_info *revs, struct commit *commit,
break;
continue;
}
- return -1;
+
+ if (!revs->do_not_die_on_missing_objects)
+ return -1;
+ else
+ p->object.flags |= MISSING;
}
if (revs->sources) {
char **slot = revision_sources_at(revs->sources, p);
diff --git a/revision.h b/revision.h
index c73c92ef40..07906bc3bc 100644
--- a/revision.h
+++ b/revision.h
@@ -41,6 +41,9 @@
/* WARNING: This is also used as REACHABLE in commit-graph.c. */
#define PULL_MERGE (1u<<15)
+/* WARNING: This is also used as NEEDS_BITMAP in pack-bitmap.c. */
+#define MISSING (1u<<22)
+
#define TOPO_WALK_EXPLORED (1u<<23)
#define TOPO_WALK_INDEGREE (1u<<24)
diff --git a/t/t6022-rev-list-missing.sh b/t/t6022-rev-list-missing.sh
new file mode 100755
index 0000000000..bbff66e4fc
--- /dev/null
+++ b/t/t6022-rev-list-missing.sh
@@ -0,0 +1,74 @@
+#!/bin/sh
+
+test_description='handling of missing objects in rev-list'
+
+TEST_PASSES_SANITIZE_LEAK=true
+. ./test-lib.sh
+
+# We setup the repository with two commits, this way HEAD is always
+# available and we can hide commit 1.
+test_expect_success 'create repository and alternate directory' '
+ test_commit 1 &&
+ test_commit 2
+'
+
+for obj in "HEAD~1" "HEAD~1^{tree}" "HEAD:1.t"
+do
+ test_expect_success "rev-list --missing=error fails with missing object $obj" '
+ oid="$(git rev-parse $obj)" &&
+ path=".git/objects/$(test_oid_to_path $oid)" &&
+
+ mv "$path" "$path.hidden" &&
+ test_when_finished "mv $path.hidden $path" &&
+
+ test_must_fail git rev-list --missing=error --objects \
+ --no-object-names HEAD
+ '
+done
+
+for obj in "HEAD~1" "HEAD~1^{tree}" "HEAD:1.t"
+do
+ for action in "allow-any" "print"
+ do
+ test_expect_success "rev-list --missing=$action with missing $obj" '
+ oid="$(git rev-parse $obj)" &&
+ path=".git/objects/$(test_oid_to_path $oid)" &&
+
+ # Before the object is made missing, we use rev-list to
+ # get the expected oids.
+ git rev-list --objects --no-object-names \
+ HEAD ^$obj >expect.raw &&
+
+ # Since both the commits have the `1.t` blob, rev-list
+ # will print it since its reachable from either commit. Unless
+ # the blob itself is missing.
+ if [ $obj != "HEAD:1.t" ]; then
+ echo $(git rev-parse HEAD:1.t) >>expect.raw
+ fi &&
+
+ mv "$path" "$path.hidden" &&
+ test_when_finished "mv $path.hidden $path" &&
+
+ git rev-list --missing=$action --objects --no-object-names \
+ HEAD >actual.raw &&
+
+ # When the action is to print, we should also add the missing
+ # oid to the expect list.
+ case $action in
+ allow-any)
+ ;;
+ print)
+ grep ?$oid actual.raw &&
+ echo ?$oid >>expect.raw
+ ;;
+ esac &&
+
+ sort actual.raw >actual &&
+ sort expect.raw >expect &&
+ test_cmp expect actual
+ '
+ done
+done
+
+
+test_done
--
2.41.0
