Empty branches (either new or reset-ed) have null_sha1 in fast-import
internals. These null_sha1 heads can slip to the real commit objects.
- parse_merge() had no check against null_sha1, so add it.
- parse_from() didn't have it too. It doesn't cause null_sha1 to slip
because for the first parent there is a null_sha1 check. But still
the input with "from empty_branch" must be rejected, make it so via
adding the check to parse_from().
There is a special case with "merge branch_itself" command. When the
branch_itself is empty it must clearly be rejected. Though in a
presence of "from ..." command it is not. parse_from() writes the new
first parent sha1 to branch->sha1 as a temporary placeholder, which
parse_merge() then picks up. Though this sha1 might have never been a
tip of the branch_itself at all.
Make parse_from() store the first parent sha1 in a temporary buffer
to fix this special case.
Add some tests for all these fixes.
Signed-off-by: Dmitry Ivankov <divanorama@xxxxxxxxx>
---
fast-import.c | 49 +++++++++++++++++++++++++++++------------------
t/t9300-fast-import.sh | 48 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 78 insertions(+), 19 deletions(-)
diff --git a/fast-import.c b/fast-import.c
index eed97c8..2e089a8 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -2540,7 +2540,8 @@ static void file_change_deleteall(struct branch *b)
b->num_notes = 0;
}
-static void parse_from_commit(struct branch *b, char *buf, unsigned long size)
+static void parse_from_commit(struct branch *b, unsigned char *sha1,
+ char *buf, unsigned long size)
{
if (!buf || size < 46)
die("Not a valid commit: %s", sha1_to_hex(b->sha1));
@@ -2551,29 +2552,31 @@ static void parse_from_commit(struct branch *b, char *buf, unsigned long size)
b->branch_tree.versions[1].sha1);
}
-static void parse_from_existing(struct branch *b)
+static void parse_from_existing(struct branch *b, unsigned char *sha1)
{
- if (is_null_sha1(b->sha1)) {
+ if (is_null_sha1(sha1)) {
hashclr(b->branch_tree.versions[0].sha1);
hashclr(b->branch_tree.versions[1].sha1);
} else {
unsigned long size;
char *buf;
- buf = read_object_with_reference(b->sha1,
- commit_type, &size, b->sha1);
- parse_from_commit(b, buf, size);
+ buf = read_object_with_reference(sha1,
+ commit_type, &size, sha1);
+ parse_from_commit(b, sha1, buf, size);
free(buf);
}
}
-static int parse_from(struct branch *b)
+static int parse_from(struct branch *b, unsigned char *sha1out)
{
const char *from;
struct branch *s;
- if (prefixcmp(command_buf.buf, "from "))
+ if (prefixcmp(command_buf.buf, "from ")) {
+ hashclr(sha1out);
return 0;
+ }
if (b->branch_tree.tree) {
release_tree_content_recursive(b->branch_tree.tree);
@@ -2586,7 +2589,10 @@ static int parse_from(struct branch *b)
die("Can't create a branch from itself: %s", b->name);
else if (s) {
unsigned char *t = s->branch_tree.versions[1].sha1;
- hashcpy(b->sha1, s->sha1);
+ if (is_null_sha1(s->sha1))
+ die("Can't create a branch from an empty branch:"
+ " %s from %s", b->name, s->name);
+ hashcpy(sha1out, s->sha1);
hashcpy(b->branch_tree.versions[0].sha1, t);
hashcpy(b->branch_tree.versions[1].sha1, t);
} else if (*from == ':') {
@@ -2594,16 +2600,16 @@ static int parse_from(struct branch *b)
struct object_entry *oe = find_mark(idnum);
if (oe->type != OBJ_COMMIT)
die("Mark :%" PRIuMAX " not a commit", idnum);
- hashcpy(b->sha1, oe->idx.sha1);
+ hashcpy(sha1out, oe->idx.sha1);
if (oe->pack_id != MAX_PACK_ID) {
unsigned long size;
char *buf = gfi_unpack_entry(oe, &size);
- parse_from_commit(b, buf, size);
+ parse_from_commit(b, sha1out, buf, size);
free(buf);
} else
- parse_from_existing(b);
- } else if (!get_sha1(from, b->sha1))
- parse_from_existing(b);
+ parse_from_existing(b, sha1out);
+ } else if (!get_sha1(from, sha1out))
+ parse_from_existing(b, sha1out);
else
die("Invalid ref name or SHA1 expression: %s", from);
@@ -2622,9 +2628,11 @@ static struct hash_list *parse_merge(unsigned int *count)
from = strchr(command_buf.buf, ' ') + 1;
n = xmalloc(sizeof(*n));
s = lookup_branch(from);
- if (s)
+ if (s) {
+ if (is_null_sha1(s->sha1))
+ die("Can't merge empty branch: %s", s->name);
hashcpy(n->sha1, s->sha1);
- else if (*from == ':') {
+ } else if (*from == ':') {
uintmax_t idnum = parse_mark_ref_eol(from);
struct object_entry *oe = find_mark(idnum);
if (oe->type != OBJ_COMMIT)
@@ -2656,6 +2664,7 @@ static void parse_new_commit(void)
{
static struct strbuf msg = STRBUF_INIT;
struct branch *b;
+ unsigned char sha1[20];
char *sp;
char *author = NULL;
char *committer = NULL;
@@ -2683,7 +2692,7 @@ static void parse_new_commit(void)
die("Expected committer but didn't get one");
parse_data(&msg, 0, NULL);
read_next_command();
- parse_from(b);
+ parse_from(b, sha1);
merge_list = parse_merge(&merge_count);
/* ensure the branch is active/loaded */
@@ -2730,7 +2739,9 @@ static void parse_new_commit(void)
strbuf_reset(&new_data);
strbuf_addf(&new_data, "tree %s\n",
sha1_to_hex(b->branch_tree.versions[1].sha1));
- if (!is_null_sha1(b->sha1))
+ if (!is_null_sha1(sha1))
+ strbuf_addf(&new_data, "parent %s\n", sha1_to_hex(sha1));
+ else if (!is_null_sha1(b->sha1))
strbuf_addf(&new_data, "parent %s\n", sha1_to_hex(b->sha1));
while (merge_list) {
struct hash_list *next = merge_list->next;
@@ -2855,7 +2866,7 @@ static void parse_reset_branch(void)
else
b = new_branch(sp);
read_next_command();
- parse_from(b);
+ parse_from(b, b->sha1);
if (command_buf.len > 0)
unread_command_buf = 1;
}
diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index 2aa1824..5f25c01 100755
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -2895,6 +2895,54 @@ test_expect_success 'S: merge with garbage after mark must fail' '
test_i18ngrep "after mark" err
'
+test_expect_success 'S: empty branch as merge parent must fail' '
+ test_must_fail git fast-import <<-EOF 2>err &&
+ commit refs/heads/chicken
+ committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+ data <<COMMIT
+ I am the chicken.
+ COMMIT
+ merge refs/heads/chicken
+ EOF
+ cat err &&
+ test_must_fail git rev-parse --verify refs/heads/chicken^
+'
+
+test_expect_success 'S: empty branch as merge parent must fail (2)' '
+ test_must_fail git fast-import <<-EOF 2>err &&
+ commit refs/heads/egg1
+ committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+ data <<COMMIT
+ I am the egg N1.
+ COMMIT
+
+ commit refs/heads/egg2
+ committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+ data <<COMMIT
+ I am the egg N2.
+ COMMIT
+ from refs/heads/egg1
+ merge refs/heads/egg2
+ EOF
+ cat err &&
+ test_must_fail git rev-parse --verify refs/heads/egg2^2
+'
+
+test_expect_success 'S: empty branch as a parent must fail ' '
+ test_must_fail git fast-import <<-EOF 2>err &&
+ reset refs/heads/egg3
+
+ commit refs/heads/egg4
+ committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+ data <<COMMIT
+ I am the egg N4.
+ COMMIT
+ from refs/heads/egg3
+ EOF
+ cat err &&
+ test_must_fail git rev-parse --verify refs/heads/egg4^2
+'
+
#
# tag, from markref
#
--
1.7.3.4
--
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