Re: [PATCH] replace: fix replacing object with itself
From: Junio C Hamano <hidden>
Date: 2016-06-15 23:02:57
Manzur Mukhitdinov [off-list ref] writes:
When object is replaced with itself git shows unhelpful messages like(git log):
"fatal: replace depth too high for object <SHA1>"
Prevents user from replacing object with itself(with test for checking
this case).
Signed-off-by: Manzur Mukhitdinov <redacted>
---
The patch is not wrong per-se, but I wonder how useful this "do not
replace itself but all other forms of loops are not checked at all"
would be in practice. If your user did this:
git replace A B ;# pretend as if what is in B is in A
git replace B C ;# pretend as if what is in C is in B
git replace C A ;# pretend as if we have loop
git log C
she would not be helped with this patch at all, no?
We have the "replace depth" thing, which is a poor-man's substitute
for loop detection, primarily because we do not want to incur high
cost of loop detection at runtime. Shouldn't we be doing at least
the same amount of loop-avoidance check, if we really want to avoid
triggering the "replace depth" check at runtime?
quoted hunk
builtin/replace.c | 8 +++----- t/t6050-replace.sh | 11 +++++++++-- 2 files changed, 12 insertions(+), 7 deletions(-)diff --git a/builtin/replace.c b/builtin/replace.c index 294b61b..628377a 100644 --- a/builtin/replace.c +++ b/builtin/replace.c@@ -157,6 +157,9 @@ static int replace_object_sha1(const char *object_ref, char ref[PATH_MAX]; struct ref_lock *lock; + if (!hashcmp(object, repl)) + return error("new object is the same as the old one: '%s'", sha1_to_hex(object)); + obj_type = sha1_object_info(object, NULL); repl_type = sha1_object_info(repl, NULL); if (!force && obj_type != repl_type)@@ -295,9 +298,6 @@ static int edit_and_replace(const char *object_ref, int force, int raw) free(tmpfile); - if (!hashcmp(old, new)) - return error("new object is the same as the old one: '%s'", sha1_to_hex(old)); - return replace_object_sha1(object_ref, old, "replacement", new, force); }@@ -406,8 +406,6 @@ static int create_graft(int argc, const char **argv, int force) strbuf_release(&buf); - if (!hashcmp(old, new)) - return error("new commit is the same as the old one: '%s'", sha1_to_hex(old)); return replace_object_sha1(old_ref, old, "replacement", new, force); }diff --git a/t/t6050-replace.sh b/t/t6050-replace.sh index 4d5a25e..5f96374 100755 --- a/t/t6050-replace.sh +++ b/t/t6050-replace.sh@@ -369,9 +369,8 @@ test_expect_success '--edit with and without already replaced object' ' git cat-file commit "$PARA3" | grep "A fake Thor" ' -test_expect_success '--edit and change nothing or command failed' ' +test_expect_success '--edit with failed editor' ' git replace -d "$PARA3" && - test_must_fail env GIT_EDITOR=true git replace --edit "$PARA3" && test_must_fail env GIT_EDITOR="./fakeeditor;false" git replace --edit "$PARA3" && GIT_EDITOR=./fakeeditor git replace --edit "$PARA3" && git replace -l | grep "$PARA3" &&@@ -440,4 +439,12 @@ test_expect_success GPG '--graft on a commit with a mergetag' ' git replace -d $HASH10 ' +test_expect_success 'replacing object with itself must fail' ' + test_must_fail git replace $HASH1 $HASH1 && + HASH8=$(git rev-parse --verify HEAD) && + test_must_fail git replace HEAD $HASH8 && + test_must_fail git replace --graft HEAD HEAD^ && + test_must_fail env GIT_EDITOR=true git replace --edit HEAD +' + test_done