patch, 2 partsfast-import: fix segfault and tests

>  t/t9300-fast-import.sh | 46 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 46 insertions(+)
>
> diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
> index 5fc9ef2..3d557b3 100755
> --- a/t/t9300-fast-import.sh
> +++ b/t/t9300-fast-import.sh
> @@ -3017,4 +3017,50 @@ test_expect_success 'T: empty reset doesnt delete branch' '
>  	git rev-parse --verify refs/heads/not-to-delete
>  '
>  
> +###
> +### series U (filedelete)
> +###
> +
> +cat >input <<INPUT_END
> +commit refs/heads/U
> +committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
> +data <<COMMIT
> +test setup
> +COMMIT
> +M 100644 inline hello.c
> +data <<BLOB
> +blob 1
> +BLOB
> +
> +INPUT_END
> +
> +test_expect_success 'U: initialize for U tests' '
> +	git fast-import <input
> +'
> +
> +cat >input <<INPUT_END
> +commit refs/heads/U
> +committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
> +data <<COMMIT
> +must succeed
> +COMMIT
> +from refs/heads/U^0
> +D ""
> +
> +INPUT_END
> +
> +test_expect_success 'U: filedelete root succeeds' '
> +    git fast-import <input
> +'
> +
> +cat >expect <<EOF
> +:100644 000000 c18147dc648481eeb65dc5e66628429a64843327 0000000000000000000000000000000000000000 D	hello.c
> +EOF
> +
> +git diff-tree -M -r U^1 U >actual
> +
> +test_expect_success 'U: validate filedelete result' '
> +	compare_diff_raw expect actual
> +'
> +
>  test_done

> You may have been concentrating on the "delete root" case, but as
> long as you claim "We add a series to test filedelete command", it
> would be sensible to test more typical cases of deleting files, not
> the entire tree as well, no?  Perhaps add three paths in the initial
> commit e.g. hello.c, good/night.txt and good/bye.txt, first remove
> good/night.txt and validate the result, then remove good/ directory
> and validate the result, and finally remove the whole thing and
> validate the result, or something like that?

> In a patch series that introduces a demonstration of existing
> breakage and then fixes the breakage in a separate patch, mark the
> test that shows the known breakage with test_expect_failure and then
> turn that line into test_expect_success in the later patch that
> fixes the breakage.

> Branch tree is NULLified by filedelete command if we are trying
> to delete root tree. Add sanity check and use load_tree() in that case.
>
> Signed-off-by: Maxim Bublis <satori@yandex-team.ru>
> ---
>  fast-import.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/fast-import.c b/fast-import.c
> index d73f58c..b77f12c 100644
> --- a/fast-import.c
> +++ b/fast-import.c
> @@ -1419,7 +1419,7 @@ static void mktree(struct tree_content *t, int v, struct strbuf *b)
>  
>  static void store_tree(struct tree_entry *root)
>  {
> -	struct tree_content *t = root->tree;
> +	struct tree_content *t;
>  	unsigned int i, j, del;
>  	struct last_object lo = { STRBUF_INIT, 0, 0, /* no_swap */ 1 };
>  	struct object_entry *le = NULL;
> @@ -1427,6 +1427,10 @@ static void store_tree(struct tree_entry *root)
>  	if (!is_null_sha1(root->versions[1].sha1))
>  		return;
>  
> +	if (!root->tree)
> +		load_tree(root)

> +	t = root->tree;
> +
>  	for (i = 0; i < t->entry_count; i++) {
>  		if (t->entries[i]->tree)
>  			store_tree(t->entries[i]);