[PATCH] mktree: Make '--missing' behave as documented

[Richard Oliver <roliver@roku.com>]

On 15/06/2022 22:01, Junio C Hamano wrote:
> We by grave mistake at 31c8221a (mktree: validate entry type in
> input, 2009-05-14) started insisting on inspecting objects even when
> allow-mising was given.  I do not think it was sensible, given why
> we had "--missing" as an option to allow users to say "you do not
> have to be too paranoid".
> 
> The codebase is so distant but I think we should probably do a moral
> revert/reconstruct of that commit so that the extra paranoia of the
> said commit applies only when "--missing" is not in effect, or
> something like that.

-- >8 --
Subject: [PATCH] mktree: Make '--missing' behave as documented

Do not make use of the object store to verify object type for
'allow_missing' objects in mktree_line(). GIT-MKTREE(1) documents
'--missing' as disabling "verif[ication] that each tree entry's sha1
identifies an existing object".

This change retains the check for '<mode>' and '<type>' for
'allow_missing' objects as this check is merely input validation that
avoids interrogating the object store.

Signed-off-by: Richard Oliver <roliver@roku.com>
---
 builtin/mktree.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/builtin/mktree.c b/builtin/mktree.c
index 902edba6d2..f41fda6e7d 100644
--- a/builtin/mktree.c
+++ b/builtin/mktree.c
@@ -116,15 +116,12 @@ static void mktree_line(char *buf, int nul_term_line, int allow_missing)
 			path, ptr, type_name(mode_type));
 	}
 
-	/* Check the type of object identified by sha1 */
-	obj_type = oid_object_info(the_repository, &oid, NULL);
-	if (obj_type < 0) {
-		if (allow_missing) {
-			; /* no problem - missing objects are presumed to be of the right type */
-		} else {
+	if (!allow_missing) {
+		/* Check the type of object identified by sha1 */
+		obj_type = oid_object_info(the_repository, &oid, NULL);
+		if (obj_type < 0) {
 			die("entry '%s' object %s is unavailable", path, oid_to_hex(&oid));
 		}
-	} else {
 		if (obj_type != mode_type) {
 			/*
 			 * The object exists but is of the wrong type.
-- 
2.36.1.467.g4f6db706e6.dirty