[PATCH] [Outreachy PATCH] t4041: use submodule repository for commit abbreviations

[PATCH] [Outreachy PATCH] t4041: use submodule repository for commit abbreviations

[Srujith A Poojary via GitGitGadget]

From: Srujith A Poojary <poojarysrujith@gmail.com>

Use the submodule repository when abbreviating commit IDs in
submodule diff headers, so uniqueness is checked against the
correct object database.

Signed-off-by: Srujith A Poojary <poojarysrujith@gmail.com>
---
    [Outreachy PATCH] t4041: use submodule repository for commit
    abbreviations

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2288%2Fpoojarysrujith%2Fmicroproject-git-libification-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2288/poojarysrujith/microproject-git-libification-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/2288

 submodule.c                      | 10 ++++++++--
 t/t4041-diff-submodule-option.sh | 18 ++++++++++++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/submodule.c b/submodule.c
index 6fcb606f7e..2215a50d9c 100644
--- a/submodule.c
+++ b/submodule.c
@@ -599,9 +599,15 @@ static void show_submodule_header(struct diff_options *o,
 
 output_header:
 	strbuf_addf(&sb, "Submodule %s ", path);
-	strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
+	if (sub)
+		strbuf_repo_add_unique_abbrev(&sb, sub, one, DEFAULT_ABBREV);
+	else
+		strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
 	strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
-	strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
+	if (sub)
+		strbuf_repo_add_unique_abbrev(&sb, sub, two, DEFAULT_ABBREV);
+	else
+		strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
 	if (message)
 		strbuf_addf(&sb, " %s\n", message);
 	else
diff --git a/t/t4041-diff-submodule-option.sh b/t/t4041-diff-submodule-option.sh
index 4dd4954260..e80472af32 100755
--- a/t/t4041-diff-submodule-option.sh
+++ b/t/t4041-diff-submodule-option.sh
@@ -14,6 +14,24 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
 
+test_expect_success SHA1 'submodule commit abbreviation uses submodule object database' '
+	test_when_finished "rm -rf collision-super" &&
+	git init -q collision-super &&
+	git init -q collision-super/sm1 &&
+	printf "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n\nb1rwzyc3\n" >collision-super/sm1/a0blgqsjc &&
+	git -C collision-super/sm1 add a0blgqsjc &&
+	tree=$(git -C collision-super/sm1 write-tree) &&
+	commit1=$(GIT_AUTHOR_DATE="1112911993 -0700" GIT_COMMITTER_DATE="1112911993 -0700" git -C collision-super/sm1 commit-tree "$tree" -m a2onsxbvj) &&
+	commit2=$(printf "child\n" | GIT_AUTHOR_DATE="1112912053 -0700" GIT_COMMITTER_DATE="1112912053 -0700" git -C collision-super/sm1 commit-tree "$tree" -p "$commit1") &&
+	git -C collision-super/sm1 checkout -q "$commit2" &&
+	git -C collision-super update-index --add --cacheinfo 160000,"$commit1",sm1 &&
+	git -C collision-super commit -q -m "Add submodule" &&
+	git -C collision-super diff --submodule=log >actual &&
+	printf "Submodule sm1 0000000000e..%s:\n  > child\n" \
+		"$(git -C collision-super/sm1 rev-parse --short "$commit2")" >expected &&
+	test_cmp expected actual
+'
+
 # Test non-UTF-8 encoding in case iconv is available.
 if test_have_prereq ICONV
 then

base-commit: 50fe5cc63f9cd6e89b87a2c9ccf96a444f4cfdb7
-- 
gitgitgadget

Re: [PATCH] [Outreachy PATCH] t4041: use submodule repository for commit abbreviations

[Okhuomon Ajayi]

Hi Srujith,

I applied this on top of master and ran t4041. The new test fails
without the submodule.c change and passes with it, so it does catch
the problem.

A few small things:

On Sat, Oct 31, 2026 at 9:26 AM Srujith A Poojary via GitGitGadget
<gitgitgadget@gmail.com> wrote:
> Use the submodule repository when abbreviating commit IDs in
> submodule diff headers, so uniqueness is checked against the
> correct object database.

It would help to first describe what happens today: the commit IDs
in the "Submodule ..." header are abbreviated against the
superproject's objects, even though the commits live in the
submodule, so the abbreviation may not be unique there.

> [Outreachy PATCH] t4041: use submodule repository for commit
> abbreviations

The change itself is in submodule.c, so the title might read better
with that area, e.g. "submodule: use the submodule repository to
abbreviate commits".

> - strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
> + if (sub)
> + strbuf_repo_add_unique_abbrev(&sb, sub, one, DEFAULT_ABBREV);
> + else
> + strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);

The same if/else appears twice. Maybe choose the repository once,
at the top of the function, and call strbuf_repo_add_unique_abbrev()
with it in both places. I also wonder whether the fallback could be
o->repo instead of the_repository, since the diff options already
carry a repository.

Thanks,
Okhuomon

[PATCH v2] Submodule: use the submodule repository to abbreviate commits

[Srujith A Poojary via GitGitGadget]

From: Srujith A Poojary <poojarysrujith@gmail.com>

The commit IDs shown in a submodule diff header belong to the
submodule's object database. However, strbuf_add_unique_abbrev()
uses the_repository, so it checks the superproject's object
database when abbreviating those IDs.

Use the submodule repository when it is available, and fall back
to the repository from the diff options when it is not.

Signed-off-by: Srujith A Poojary <poojarysrujith@gmail.com>
---
    [Outreachy PATCH] t4041: use submodule repository for commit
    abbreviations

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2288%2Fpoojarysrujith%2Fmicroproject-git-libification-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2288/poojarysrujith/microproject-git-libification-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/2288

Range-diff vs v1:

 1:  7b2af1b46a ! 1:  3133cd3017 [Outreachy PATCH] t4041: use submodule repository for commit abbreviations
     @@ Metadata
      Author: Srujith A Poojary <poojarysrujith@gmail.com>
      
       ## Commit message ##
     -    [Outreachy PATCH] t4041: use submodule repository for commit abbreviations
     +    Submodule: use the submodule repository to abbreviate commits
      
     -    Use the submodule repository when abbreviating commit IDs in
     -    submodule diff headers, so uniqueness is checked against the
     -    correct object database.
     +    The commit IDs shown in a submodule diff header belong to the
     +    submodule's object database. However, strbuf_add_unique_abbrev()
     +    uses the_repository, so it checks the superproject's object
     +    database when abbreviating those IDs.
     +
     +    Use the submodule repository when it is available, and fall back
     +    to the repository from the diff options when it is not.
      
          Signed-off-by: Srujith A Poojary <poojarysrujith@gmail.com>
      
       ## submodule.c ##
      @@ submodule.c: static void show_submodule_header(struct diff_options *o,
     + 		struct commit **left, struct commit **right,
     + 		struct commit_list **merge_bases)
     + {
     ++	struct repository *repo = sub ? sub : o->repo;
     + 	const char *message = NULL;
     + 	struct strbuf sb = STRBUF_INIT;
     + 	int fast_forward = 0, fast_backward = 0;
     +@@ submodule.c: static void show_submodule_header(struct diff_options *o,
       
       output_header:
       	strbuf_addf(&sb, "Submodule %s ", path);
      -	strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
     -+	if (sub)
     -+		strbuf_repo_add_unique_abbrev(&sb, sub, one, DEFAULT_ABBREV);
     -+	else
     -+		strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
     ++	strbuf_repo_add_unique_abbrev(&sb, repo, one, DEFAULT_ABBREV);
       	strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
      -	strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
     -+	if (sub)
     -+		strbuf_repo_add_unique_abbrev(&sb, sub, two, DEFAULT_ABBREV);
     -+	else
     -+		strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
     ++	strbuf_repo_add_unique_abbrev(&sb, repo, two, DEFAULT_ABBREV);
       	if (message)
       		strbuf_addf(&sb, " %s\n", message);
       	else


 submodule.c                      |  5 +++--
 t/t4041-diff-submodule-option.sh | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/submodule.c b/submodule.c
index 6fcb606f7e..1302c11ddf 100644
--- a/submodule.c
+++ b/submodule.c
@@ -543,6 +543,7 @@ static void show_submodule_header(struct diff_options *o,
 		struct commit **left, struct commit **right,
 		struct commit_list **merge_bases)
 {
+	struct repository *repo = sub ? sub : o->repo;
 	const char *message = NULL;
 	struct strbuf sb = STRBUF_INIT;
 	int fast_forward = 0, fast_backward = 0;
@@ -599,9 +600,9 @@ static void show_submodule_header(struct diff_options *o,
 
 output_header:
 	strbuf_addf(&sb, "Submodule %s ", path);
-	strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
+	strbuf_repo_add_unique_abbrev(&sb, repo, one, DEFAULT_ABBREV);
 	strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
-	strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
+	strbuf_repo_add_unique_abbrev(&sb, repo, two, DEFAULT_ABBREV);
 	if (message)
 		strbuf_addf(&sb, " %s\n", message);
 	else
diff --git a/t/t4041-diff-submodule-option.sh b/t/t4041-diff-submodule-option.sh
index 4dd4954260..e80472af32 100755
--- a/t/t4041-diff-submodule-option.sh
+++ b/t/t4041-diff-submodule-option.sh
@@ -14,6 +14,24 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
 
+test_expect_success SHA1 'submodule commit abbreviation uses submodule object database' '
+	test_when_finished "rm -rf collision-super" &&
+	git init -q collision-super &&
+	git init -q collision-super/sm1 &&
+	printf "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n\nb1rwzyc3\n" >collision-super/sm1/a0blgqsjc &&
+	git -C collision-super/sm1 add a0blgqsjc &&
+	tree=$(git -C collision-super/sm1 write-tree) &&
+	commit1=$(GIT_AUTHOR_DATE="1112911993 -0700" GIT_COMMITTER_DATE="1112911993 -0700" git -C collision-super/sm1 commit-tree "$tree" -m a2onsxbvj) &&
+	commit2=$(printf "child\n" | GIT_AUTHOR_DATE="1112912053 -0700" GIT_COMMITTER_DATE="1112912053 -0700" git -C collision-super/sm1 commit-tree "$tree" -p "$commit1") &&
+	git -C collision-super/sm1 checkout -q "$commit2" &&
+	git -C collision-super update-index --add --cacheinfo 160000,"$commit1",sm1 &&
+	git -C collision-super commit -q -m "Add submodule" &&
+	git -C collision-super diff --submodule=log >actual &&
+	printf "Submodule sm1 0000000000e..%s:\n  > child\n" \
+		"$(git -C collision-super/sm1 rev-parse --short "$commit2")" >expected &&
+	test_cmp expected actual
+'
+
 # Test non-UTF-8 encoding in case iconv is available.
 if test_have_prereq ICONV
 then

base-commit: 50fe5cc63f9cd6e89b87a2c9ccf96a444f4cfdb7
-- 
gitgitgadget

Re: [PATCH] [Outreachy PATCH] t4041: use submodule repository for commit abbreviations

[Srujith Poojary]

On Sat, Oct 31, 2026 at 10:16 PM Okhuomon Ajayi
<okhuomonajayi54@gmail.com> wrote:
>
> Hi Srujith,
>
> I applied this on top of master and ran t4041. The new test fails
> without the submodule.c change and passes with it, so it does catch
> the problem.
>
> A few small things:
>
> On Sat, Oct 31, 2026 at 9:26 AM Srujith A Poojary via GitGitGadget
> <gitgitgadget@gmail.com> wrote:
> > Use the submodule repository when abbreviating commit IDs in
> > submodule diff headers, so uniqueness is checked against the
> > correct object database.
>
> It would help to first describe what happens today: the commit IDs
> in the "Submodule ..." header are abbreviated against the
> superproject's objects, even though the commits live in the
> submodule, so the abbreviation may not be unique there.
>
> > [Outreachy PATCH] t4041: use submodule repository for commit
> > abbreviations
>
> The change itself is in submodule.c, so the title might read better
> with that area, e.g. "submodule: use the submodule repository to
> abbreviate commits".
>
> > - strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
> > + if (sub)
> > + strbuf_repo_add_unique_abbrev(&sb, sub, one, DEFAULT_ABBREV);
> > + else
> > + strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
>
> The same if/else appears twice. Maybe choose the repository once,
> at the top of the function, and call strbuf_repo_add_unique_abbrev()
> with it in both places. I also wonder whether the fallback could be
> o->repo instead of the_repository, since the diff options already
> carry a repository.
>
> Thanks,
> Okhuomon

Hi Okhuomon,

Thanks for reviewing the patch and testing the new test case.

I've made the suggested changes and submitted v2. I now use `sub` when
available and fall back to `o->repo` when it isn't. I also simplified
the code and updated the commit message.

Here is the updated patch:
https://lore.kernel.org/git/pull.2288.v2.git.1793473062113.gitgitgadget@gmail.com

Thanks again!

Regards,
Srujith

Re: [PATCH v2] Submodule: use the submodule repository to abbreviate commits

[Okhuomon Ajayi]

Hi Srujith,

On Sat, Oct 31, 2026 at 7:57 PM Srujith A Poojary via GitGitGadget
<gitgitgadget@gmail.com> wrote:
> + struct repository *repo = sub ? sub : o->repo;

Thanks, v2 looks good to me.

> Submodule: use the submodule repository to abbreviate commits

One small nit: "git log --no-merges submodule.c" shows the area is
always written in lowercase ("submodule:"), so "submodule: use the
submodule repository to abbreviate commits" would match.

Thanks,
Okhuomon

On Sat, Oct 31, 2026 at 7:57 PM Srujith A Poojary via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: Srujith A Poojary <poojarysrujith@gmail.com>
>
> The commit IDs shown in a submodule diff header belong to the
> submodule's object database. However, strbuf_add_unique_abbrev()
> uses the_repository, so it checks the superproject's object
> database when abbreviating those IDs.
>
> Use the submodule repository when it is available, and fall back
> to the repository from the diff options when it is not.
>
> Signed-off-by: Srujith A Poojary <poojarysrujith@gmail.com>
> ---
>     [Outreachy PATCH] t4041: use submodule repository for commit
>     abbreviations
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2288%2Fpoojarysrujith%2Fmicroproject-git-libification-v2
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2288/poojarysrujith/microproject-git-libification-v2
> Pull-Request: https://github.com/gitgitgadget/git/pull/2288
>
> Range-diff vs v1:
>
>  1:  7b2af1b46a ! 1:  3133cd3017 [Outreachy PATCH] t4041: use submodule repository for commit abbreviations
>      @@ Metadata
>       Author: Srujith A Poojary <poojarysrujith@gmail.com>
>
>        ## Commit message ##
>      -    [Outreachy PATCH] t4041: use submodule repository for commit abbreviations
>      +    Submodule: use the submodule repository to abbreviate commits
>
>      -    Use the submodule repository when abbreviating commit IDs in
>      -    submodule diff headers, so uniqueness is checked against the
>      -    correct object database.
>      +    The commit IDs shown in a submodule diff header belong to the
>      +    submodule's object database. However, strbuf_add_unique_abbrev()
>      +    uses the_repository, so it checks the superproject's object
>      +    database when abbreviating those IDs.
>      +
>      +    Use the submodule repository when it is available, and fall back
>      +    to the repository from the diff options when it is not.
>
>           Signed-off-by: Srujith A Poojary <poojarysrujith@gmail.com>
>
>        ## submodule.c ##
>       @@ submodule.c: static void show_submodule_header(struct diff_options *o,
>      +          struct commit **left, struct commit **right,
>      +          struct commit_list **merge_bases)
>      + {
>      ++ struct repository *repo = sub ? sub : o->repo;
>      +  const char *message = NULL;
>      +  struct strbuf sb = STRBUF_INIT;
>      +  int fast_forward = 0, fast_backward = 0;
>      +@@ submodule.c: static void show_submodule_header(struct diff_options *o,
>
>        output_header:
>         strbuf_addf(&sb, "Submodule %s ", path);
>       - strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
>      -+ if (sub)
>      -+         strbuf_repo_add_unique_abbrev(&sb, sub, one, DEFAULT_ABBREV);
>      -+ else
>      -+         strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
>      ++ strbuf_repo_add_unique_abbrev(&sb, repo, one, DEFAULT_ABBREV);
>         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
>       - strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
>      -+ if (sub)
>      -+         strbuf_repo_add_unique_abbrev(&sb, sub, two, DEFAULT_ABBREV);
>      -+ else
>      -+         strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
>      ++ strbuf_repo_add_unique_abbrev(&sb, repo, two, DEFAULT_ABBREV);
>         if (message)
>                 strbuf_addf(&sb, " %s\n", message);
>         else
>
>
>  submodule.c                      |  5 +++--
>  t/t4041-diff-submodule-option.sh | 18 ++++++++++++++++++
>  2 files changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/submodule.c b/submodule.c
> index 6fcb606f7e..1302c11ddf 100644
> --- a/submodule.c
> +++ b/submodule.c
> @@ -543,6 +543,7 @@ static void show_submodule_header(struct diff_options *o,
>                 struct commit **left, struct commit **right,
>                 struct commit_list **merge_bases)
>  {
> +       struct repository *repo = sub ? sub : o->repo;
>         const char *message = NULL;
>         struct strbuf sb = STRBUF_INIT;
>         int fast_forward = 0, fast_backward = 0;
> @@ -599,9 +600,9 @@ static void show_submodule_header(struct diff_options *o,
>
>  output_header:
>         strbuf_addf(&sb, "Submodule %s ", path);
> -       strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
> +       strbuf_repo_add_unique_abbrev(&sb, repo, one, DEFAULT_ABBREV);
>         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
> -       strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
> +       strbuf_repo_add_unique_abbrev(&sb, repo, two, DEFAULT_ABBREV);
>         if (message)
>                 strbuf_addf(&sb, " %s\n", message);
>         else
> diff --git a/t/t4041-diff-submodule-option.sh b/t/t4041-diff-submodule-option.sh
> index 4dd4954260..e80472af32 100755
> --- a/t/t4041-diff-submodule-option.sh
> +++ b/t/t4041-diff-submodule-option.sh
> @@ -14,6 +14,24 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
>
>  . ./test-lib.sh
>
> +test_expect_success SHA1 'submodule commit abbreviation uses submodule object database' '
> +       test_when_finished "rm -rf collision-super" &&
> +       git init -q collision-super &&
> +       git init -q collision-super/sm1 &&
> +       printf "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n\nb1rwzyc3\n" >collision-super/sm1/a0blgqsjc &&
> +       git -C collision-super/sm1 add a0blgqsjc &&
> +       tree=$(git -C collision-super/sm1 write-tree) &&
> +       commit1=$(GIT_AUTHOR_DATE="1112911993 -0700" GIT_COMMITTER_DATE="1112911993 -0700" git -C collision-super/sm1 commit-tree "$tree" -m a2onsxbvj) &&
> +       commit2=$(printf "child\n" | GIT_AUTHOR_DATE="1112912053 -0700" GIT_COMMITTER_DATE="1112912053 -0700" git -C collision-super/sm1 commit-tree "$tree" -p "$commit1") &&
> +       git -C collision-super/sm1 checkout -q "$commit2" &&
> +       git -C collision-super update-index --add --cacheinfo 160000,"$commit1",sm1 &&
> +       git -C collision-super commit -q -m "Add submodule" &&
> +       git -C collision-super diff --submodule=log >actual &&
> +       printf "Submodule sm1 0000000000e..%s:\n  > child\n" \
> +               "$(git -C collision-super/sm1 rev-parse --short "$commit2")" >expected &&
> +       test_cmp expected actual
> +'
> +
>  # Test non-UTF-8 encoding in case iconv is available.
>  if test_have_prereq ICONV
>  then
>
> base-commit: 50fe5cc63f9cd6e89b87a2c9ccf96a444f4cfdb7
> --
> gitgitgadget
>

[PATCH v3] submodule: use the submodule repository to abbreviate commits

[Srujith A Poojary via GitGitGadget]

From: Srujith A Poojary <poojarysrujith@gmail.com>

The commit IDs shown in a submodule diff header belong to the
submodule's object database. However, strbuf_add_unique_abbrev()
uses the_repository, so it checks the superproject's object
database when abbreviating those IDs.

Use the submodule repository when it is available, and fall back
to the repository from the diff options when it is not.

Signed-off-by: Srujith A Poojary <poojarysrujith@gmail.com>
---
    [Outreachy PATCH] t4041: use submodule repository for commit
    abbreviations

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2288%2Fpoojarysrujith%2Fmicroproject-git-libification-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2288/poojarysrujith/microproject-git-libification-v3
Pull-Request: https://github.com/gitgitgadget/git/pull/2288

Range-diff vs v2:

 1:  3133cd3017 ! 1:  a8c54b9292 Submodule: use the submodule repository to abbreviate commits
     @@ Metadata
      Author: Srujith A Poojary <poojarysrujith@gmail.com>
      
       ## Commit message ##
     -    Submodule: use the submodule repository to abbreviate commits
     +    submodule: use the submodule repository to abbreviate commits
      
          The commit IDs shown in a submodule diff header belong to the
          submodule's object database. However, strbuf_add_unique_abbrev()


 submodule.c                      |  5 +++--
 t/t4041-diff-submodule-option.sh | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/submodule.c b/submodule.c
index 6fcb606f7e..1302c11ddf 100644
--- a/submodule.c
+++ b/submodule.c
@@ -543,6 +543,7 @@ static void show_submodule_header(struct diff_options *o,
 		struct commit **left, struct commit **right,
 		struct commit_list **merge_bases)
 {
+	struct repository *repo = sub ? sub : o->repo;
 	const char *message = NULL;
 	struct strbuf sb = STRBUF_INIT;
 	int fast_forward = 0, fast_backward = 0;
@@ -599,9 +600,9 @@ static void show_submodule_header(struct diff_options *o,
 
 output_header:
 	strbuf_addf(&sb, "Submodule %s ", path);
-	strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
+	strbuf_repo_add_unique_abbrev(&sb, repo, one, DEFAULT_ABBREV);
 	strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
-	strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
+	strbuf_repo_add_unique_abbrev(&sb, repo, two, DEFAULT_ABBREV);
 	if (message)
 		strbuf_addf(&sb, " %s\n", message);
 	else
diff --git a/t/t4041-diff-submodule-option.sh b/t/t4041-diff-submodule-option.sh
index 4dd4954260..e80472af32 100755
--- a/t/t4041-diff-submodule-option.sh
+++ b/t/t4041-diff-submodule-option.sh
@@ -14,6 +14,24 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
 
+test_expect_success SHA1 'submodule commit abbreviation uses submodule object database' '
+	test_when_finished "rm -rf collision-super" &&
+	git init -q collision-super &&
+	git init -q collision-super/sm1 &&
+	printf "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n\nb1rwzyc3\n" >collision-super/sm1/a0blgqsjc &&
+	git -C collision-super/sm1 add a0blgqsjc &&
+	tree=$(git -C collision-super/sm1 write-tree) &&
+	commit1=$(GIT_AUTHOR_DATE="1112911993 -0700" GIT_COMMITTER_DATE="1112911993 -0700" git -C collision-super/sm1 commit-tree "$tree" -m a2onsxbvj) &&
+	commit2=$(printf "child\n" | GIT_AUTHOR_DATE="1112912053 -0700" GIT_COMMITTER_DATE="1112912053 -0700" git -C collision-super/sm1 commit-tree "$tree" -p "$commit1") &&
+	git -C collision-super/sm1 checkout -q "$commit2" &&
+	git -C collision-super update-index --add --cacheinfo 160000,"$commit1",sm1 &&
+	git -C collision-super commit -q -m "Add submodule" &&
+	git -C collision-super diff --submodule=log >actual &&
+	printf "Submodule sm1 0000000000e..%s:\n  > child\n" \
+		"$(git -C collision-super/sm1 rev-parse --short "$commit2")" >expected &&
+	test_cmp expected actual
+'
+
 # Test non-UTF-8 encoding in case iconv is available.
 if test_have_prereq ICONV
 then

base-commit: 50fe5cc63f9cd6e89b87a2c9ccf96a444f4cfdb7
-- 
gitgitgadget

Re: [PATCH v2] Submodule: use the submodule repository to abbreviate commits

[Srujith Poojary]

On Sun, Nov 1, 2026 at 12:39 AM Okhuomon Ajayi
<okhuomonajayi54@gmail.com> wrote:
>
> Hi Srujith,
>
> On Sat, Oct 31, 2026 at 7:57 PM Srujith A Poojary via GitGitGadget
> <gitgitgadget@gmail.com> wrote:
> > + struct repository *repo = sub ? sub : o->repo;
>
> Thanks, v2 looks good to me.
>
> > Submodule: use the submodule repository to abbreviate commits
>
> One small nit: "git log --no-merges submodule.c" shows the area is
> always written in lowercase ("submodule:"), so "submodule: use the
> submodule repository to abbreviate commits" would match.
>
> Thanks,
> Okhuomon
>
> On Sat, Oct 31, 2026 at 7:57 PM Srujith A Poojary via GitGitGadget
> <gitgitgadget@gmail.com> wrote:
> >
> > From: Srujith A Poojary <poojarysrujith@gmail.com>
> >
> > The commit IDs shown in a submodule diff header belong to the
> > submodule's object database. However, strbuf_add_unique_abbrev()
> > uses the_repository, so it checks the superproject's object
> > database when abbreviating those IDs.
> >
> > Use the submodule repository when it is available, and fall back
> > to the repository from the diff options when it is not.
> >
> > Signed-off-by: Srujith A Poojary <poojarysrujith@gmail.com>
> > ---
> >     [Outreachy PATCH] t4041: use submodule repository for commit
> >     abbreviations
> >
> > Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2288%2Fpoojarysrujith%2Fmicroproject-git-libification-v2
> > Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2288/poojarysrujith/microproject-git-libification-v2
> > Pull-Request: https://github.com/gitgitgadget/git/pull/2288
> >
> > Range-diff vs v1:
> >
> >  1:  7b2af1b46a ! 1:  3133cd3017 [Outreachy PATCH] t4041: use submodule repository for commit abbreviations
> >      @@ Metadata
> >       Author: Srujith A Poojary <poojarysrujith@gmail.com>
> >
> >        ## Commit message ##
> >      -    [Outreachy PATCH] t4041: use submodule repository for commit abbreviations
> >      +    Submodule: use the submodule repository to abbreviate commits
> >
> >      -    Use the submodule repository when abbreviating commit IDs in
> >      -    submodule diff headers, so uniqueness is checked against the
> >      -    correct object database.
> >      +    The commit IDs shown in a submodule diff header belong to the
> >      +    submodule's object database. However, strbuf_add_unique_abbrev()
> >      +    uses the_repository, so it checks the superproject's object
> >      +    database when abbreviating those IDs.
> >      +
> >      +    Use the submodule repository when it is available, and fall back
> >      +    to the repository from the diff options when it is not.
> >
> >           Signed-off-by: Srujith A Poojary <poojarysrujith@gmail.com>
> >
> >        ## submodule.c ##
> >       @@ submodule.c: static void show_submodule_header(struct diff_options *o,
> >      +          struct commit **left, struct commit **right,
> >      +          struct commit_list **merge_bases)
> >      + {
> >      ++ struct repository *repo = sub ? sub : o->repo;
> >      +  const char *message = NULL;
> >      +  struct strbuf sb = STRBUF_INIT;
> >      +  int fast_forward = 0, fast_backward = 0;
> >      +@@ submodule.c: static void show_submodule_header(struct diff_options *o,
> >
> >        output_header:
> >         strbuf_addf(&sb, "Submodule %s ", path);
> >       - strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
> >      -+ if (sub)
> >      -+         strbuf_repo_add_unique_abbrev(&sb, sub, one, DEFAULT_ABBREV);
> >      -+ else
> >      -+         strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
> >      ++ strbuf_repo_add_unique_abbrev(&sb, repo, one, DEFAULT_ABBREV);
> >         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
> >       - strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
> >      -+ if (sub)
> >      -+         strbuf_repo_add_unique_abbrev(&sb, sub, two, DEFAULT_ABBREV);
> >      -+ else
> >      -+         strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
> >      ++ strbuf_repo_add_unique_abbrev(&sb, repo, two, DEFAULT_ABBREV);
> >         if (message)
> >                 strbuf_addf(&sb, " %s\n", message);
> >         else
> >
> >
> >  submodule.c                      |  5 +++--
> >  t/t4041-diff-submodule-option.sh | 18 ++++++++++++++++++
> >  2 files changed, 21 insertions(+), 2 deletions(-)
> >
> > diff --git a/submodule.c b/submodule.c
> > index 6fcb606f7e..1302c11ddf 100644
> > --- a/submodule.c
> > +++ b/submodule.c
> > @@ -543,6 +543,7 @@ static void show_submodule_header(struct diff_options *o,
> >                 struct commit **left, struct commit **right,
> >                 struct commit_list **merge_bases)
> >  {
> > +       struct repository *repo = sub ? sub : o->repo;
> >         const char *message = NULL;
> >         struct strbuf sb = STRBUF_INIT;
> >         int fast_forward = 0, fast_backward = 0;
> > @@ -599,9 +600,9 @@ static void show_submodule_header(struct diff_options *o,
> >
> >  output_header:
> >         strbuf_addf(&sb, "Submodule %s ", path);
> > -       strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
> > +       strbuf_repo_add_unique_abbrev(&sb, repo, one, DEFAULT_ABBREV);
> >         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
> > -       strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
> > +       strbuf_repo_add_unique_abbrev(&sb, repo, two, DEFAULT_ABBREV);
> >         if (message)
> >                 strbuf_addf(&sb, " %s\n", message);
> >         else
> > diff --git a/t/t4041-diff-submodule-option.sh b/t/t4041-diff-submodule-option.sh
> > index 4dd4954260..e80472af32 100755
> > --- a/t/t4041-diff-submodule-option.sh
> > +++ b/t/t4041-diff-submodule-option.sh
> > @@ -14,6 +14,24 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
> >
> >  . ./test-lib.sh
> >
> > +test_expect_success SHA1 'submodule commit abbreviation uses submodule object database' '
> > +       test_when_finished "rm -rf collision-super" &&
> > +       git init -q collision-super &&
> > +       git init -q collision-super/sm1 &&
> > +       printf "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n\nb1rwzyc3\n" >collision-super/sm1/a0blgqsjc &&
> > +       git -C collision-super/sm1 add a0blgqsjc &&
> > +       tree=$(git -C collision-super/sm1 write-tree) &&
> > +       commit1=$(GIT_AUTHOR_DATE="1112911993 -0700" GIT_COMMITTER_DATE="1112911993 -0700" git -C collision-super/sm1 commit-tree "$tree" -m a2onsxbvj) &&
> > +       commit2=$(printf "child\n" | GIT_AUTHOR_DATE="1112912053 -0700" GIT_COMMITTER_DATE="1112912053 -0700" git -C collision-super/sm1 commit-tree "$tree" -p "$commit1") &&
> > +       git -C collision-super/sm1 checkout -q "$commit2" &&
> > +       git -C collision-super update-index --add --cacheinfo 160000,"$commit1",sm1 &&
> > +       git -C collision-super commit -q -m "Add submodule" &&
> > +       git -C collision-super diff --submodule=log >actual &&
> > +       printf "Submodule sm1 0000000000e..%s:\n  > child\n" \
> > +               "$(git -C collision-super/sm1 rev-parse --short "$commit2")" >expected &&
> > +       test_cmp expected actual
> > +'
> > +
> >  # Test non-UTF-8 encoding in case iconv is available.
> >  if test_have_prereq ICONV
> >  then
> >
> > base-commit: 50fe5cc63f9cd6e89b87a2c9ccf96a444f4cfdb7
> > --
> > gitgitgadget

Hi Okhuomon,

Thanks for pointing that out. I've corrected the subject to use
lowercase `submodule` and submitted v3.

Regards,
Srujith
> >

Re: [PATCH v3] submodule: use the submodule repository to abbreviate commits

[Junio C Hamano]

"Srujith A Poojary via GitGitGadget" <gitgitgadget@gmail.com>
writes:

> From: Srujith A Poojary <poojarysrujith@gmail.com>
>
> The commit IDs shown in a submodule diff header belong to the
> submodule's object database. However, strbuf_add_unique_abbrev()
> uses the_repository, so it checks the superproject's object
> database when abbreviating those IDs.
>
> Use the submodule repository when it is available, and fall back
> to the repository from the diff options when it is not.

While the fallback behaviour does not make much sense (the commit
object recorded in gitlink is not expected to be found in the
superproject's repository, which is the reason why you are adding
this fix in the first place), it would mean that for unpopulated
submodules for which you haven't run "git submodule init", the
behaviour would stay the ame as before.

> diff --git a/submodule.c b/submodule.c
> index 6fcb606f7e..1302c11ddf 100644
> --- a/submodule.c
> +++ b/submodule.c
> @@ -543,6 +543,7 @@ static void show_submodule_header(struct diff_options *o,
>  		struct commit **left, struct commit **right,
>  		struct commit_list **merge_bases)
>  {
> +	struct repository *repo = sub ? sub : o->repo;
>  	const char *message = NULL;
>  	struct strbuf sb = STRBUF_INIT;
>  	int fast_forward = 0, fast_backward = 0;
> @@ -599,9 +600,9 @@ static void show_submodule_header(struct diff_options *o,
>  
>  output_header:
>  	strbuf_addf(&sb, "Submodule %s ", path);
> -	strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
> +	strbuf_repo_add_unique_abbrev(&sb, repo, one, DEFAULT_ABBREV);
>  	strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
> -	strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
> +	strbuf_repo_add_unique_abbrev(&sb, repo, two, DEFAULT_ABBREV);
>  	if (message)
>  		strbuf_addf(&sb, " %s\n", message);
>  	else

Quite straightforward.

> +test_expect_success SHA1 'submodule commit abbreviation uses submodule object database' '

Hmph.  I wonder if there is a way to use the test_oid_cache
facility to allow test with both SHA-1 and SHA-256 hashes?

Will queue.

Thanks.

[PATCH v4 0/2] [Outreachy PATCH] t4041: use submodule repository for commit abbreviations

[Srujith A Poojary via GitGitGadget]

Srujith A Poojary (2):
  submodule: use the submodule repository to abbreviate commits
  t4041: test SHA-256 submodule abbreviations

 submodule.c                      |  5 +++--
 t/t4041-diff-submodule-option.sh | 23 +++++++++++++++++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)


base-commit: 50fe5cc63f9cd6e89b87a2c9ccf96a444f4cfdb7
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2288%2Fpoojarysrujith%2Fmicroproject-git-libification-v4
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2288/poojarysrujith/microproject-git-libification-v4
Pull-Request: https://github.com/gitgitgadget/git/pull/2288

Range-diff vs v3:

 1:  a8c54b9292 = 1:  a8c54b9292 submodule: use the submodule repository to abbreviate commits
 -:  ---------- > 2:  99a1234544 t4041: test SHA-256 submodule abbreviations

-- 
gitgitgadget

[PATCH v4 1/2] submodule: use the submodule repository to abbreviate commits

[Srujith A Poojary via GitGitGadget]

From: Srujith A Poojary <poojarysrujith@gmail.com>

The commit IDs shown in a submodule diff header belong to the
submodule's object database. However, strbuf_add_unique_abbrev()
uses the_repository, so it checks the superproject's object
database when abbreviating those IDs.

Use the submodule repository when it is available, and fall back
to the repository from the diff options when it is not.

Signed-off-by: Srujith A Poojary <poojarysrujith@gmail.com>
---
 submodule.c                      |  5 +++--
 t/t4041-diff-submodule-option.sh | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/submodule.c b/submodule.c
index 6fcb606f7e..1302c11ddf 100644
--- a/submodule.c
+++ b/submodule.c
@@ -543,6 +543,7 @@ static void show_submodule_header(struct diff_options *o,
 		struct commit **left, struct commit **right,
 		struct commit_list **merge_bases)
 {
+	struct repository *repo = sub ? sub : o->repo;
 	const char *message = NULL;
 	struct strbuf sb = STRBUF_INIT;
 	int fast_forward = 0, fast_backward = 0;
@@ -599,9 +600,9 @@ static void show_submodule_header(struct diff_options *o,
 
 output_header:
 	strbuf_addf(&sb, "Submodule %s ", path);
-	strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
+	strbuf_repo_add_unique_abbrev(&sb, repo, one, DEFAULT_ABBREV);
 	strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
-	strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
+	strbuf_repo_add_unique_abbrev(&sb, repo, two, DEFAULT_ABBREV);
 	if (message)
 		strbuf_addf(&sb, " %s\n", message);
 	else
diff --git a/t/t4041-diff-submodule-option.sh b/t/t4041-diff-submodule-option.sh
index 4dd4954260..e80472af32 100755
--- a/t/t4041-diff-submodule-option.sh
+++ b/t/t4041-diff-submodule-option.sh
@@ -14,6 +14,24 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
 
+test_expect_success SHA1 'submodule commit abbreviation uses submodule object database' '
+	test_when_finished "rm -rf collision-super" &&
+	git init -q collision-super &&
+	git init -q collision-super/sm1 &&
+	printf "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n\nb1rwzyc3\n" >collision-super/sm1/a0blgqsjc &&
+	git -C collision-super/sm1 add a0blgqsjc &&
+	tree=$(git -C collision-super/sm1 write-tree) &&
+	commit1=$(GIT_AUTHOR_DATE="1112911993 -0700" GIT_COMMITTER_DATE="1112911993 -0700" git -C collision-super/sm1 commit-tree "$tree" -m a2onsxbvj) &&
+	commit2=$(printf "child\n" | GIT_AUTHOR_DATE="1112912053 -0700" GIT_COMMITTER_DATE="1112912053 -0700" git -C collision-super/sm1 commit-tree "$tree" -p "$commit1") &&
+	git -C collision-super/sm1 checkout -q "$commit2" &&
+	git -C collision-super update-index --add --cacheinfo 160000,"$commit1",sm1 &&
+	git -C collision-super commit -q -m "Add submodule" &&
+	git -C collision-super diff --submodule=log >actual &&
+	printf "Submodule sm1 0000000000e..%s:\n  > child\n" \
+		"$(git -C collision-super/sm1 rev-parse --short "$commit2")" >expected &&
+	test_cmp expected actual
+'
+
 # Test non-UTF-8 encoding in case iconv is available.
 if test_have_prereq ICONV
 then
-- 
gitgitgadget

[PATCH v4 2/2] t4041: test SHA-256 submodule abbreviations

[Srujith A Poojary via GitGitGadget]

From: Srujith A Poojary <poojarysrujith@gmail.com>

The expected abbreviation for a submodule commit depends on the
repository's hash algorithm. Use test_oid_cache to provide the
expected value for each algorithm and remove the SHA1 prerequisite
so this test runs with both SHA-1 and SHA-256.

Signed-off-by: Srujith A Poojary <poojarysrujith@gmail.com>
---
 t/t4041-diff-submodule-option.sh | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/t/t4041-diff-submodule-option.sh b/t/t4041-diff-submodule-option.sh
index e80472af32..4539d6bba5 100755
--- a/t/t4041-diff-submodule-option.sh
+++ b/t/t4041-diff-submodule-option.sh
@@ -14,7 +14,11 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
 
-test_expect_success SHA1 'submodule commit abbreviation uses submodule object database' '
+test_expect_success 'submodule commit abbreviation uses submodule object database' '
+	test_oid_cache <<-EOF &&
+	submodule_commit1_abbrev sha1:0000000000e
+	submodule_commit1_abbrev sha256:24c81a5
+	EOF
 	test_when_finished "rm -rf collision-super" &&
 	git init -q collision-super &&
 	git init -q collision-super/sm1 &&
@@ -27,7 +31,8 @@ test_expect_success SHA1 'submodule commit abbreviation uses submodule object da
 	git -C collision-super update-index --add --cacheinfo 160000,"$commit1",sm1 &&
 	git -C collision-super commit -q -m "Add submodule" &&
 	git -C collision-super diff --submodule=log >actual &&
-	printf "Submodule sm1 0000000000e..%s:\n  > child\n" \
+	printf "Submodule sm1 %s..%s:\n  > child\n" \
+		"$(test_oid submodule_commit1_abbrev)" \
 		"$(git -C collision-super/sm1 rev-parse --short "$commit2")" >expected &&
 	test_cmp expected actual
 '
-- 
gitgitgadget

Re: [PATCH v4 1/2] submodule: use the submodule repository to abbreviate commits

[Srujith Poojary]

On Tue, Nov 3, 2026 at 1:10 AM Srujith A Poojary via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: Srujith A Poojary <poojarysrujith@gmail.com>
>
> The commit IDs shown in a submodule diff header belong to the
> submodule's object database. However, strbuf_add_unique_abbrev()
> uses the_repository, so it checks the superproject's object
> database when abbreviating those IDs.
>
> Use the submodule repository when it is available, and fall back
> to the repository from the diff options when it is not.
>
> Signed-off-by: Srujith A Poojary <poojarysrujith@gmail.com>
> ---
>  submodule.c                      |  5 +++--
>  t/t4041-diff-submodule-option.sh | 18 ++++++++++++++++++
>  2 files changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/submodule.c b/submodule.c
> index 6fcb606f7e..1302c11ddf 100644
> --- a/submodule.c
> +++ b/submodule.c
> @@ -543,6 +543,7 @@ static void show_submodule_header(struct diff_options *o,
>                 struct commit **left, struct commit **right,
>                 struct commit_list **merge_bases)
>  {
> +       struct repository *repo = sub ? sub : o->repo;
>         const char *message = NULL;
>         struct strbuf sb = STRBUF_INIT;
>         int fast_forward = 0, fast_backward = 0;
> @@ -599,9 +600,9 @@ static void show_submodule_header(struct diff_options *o,
>
>  output_header:
>         strbuf_addf(&sb, "Submodule %s ", path);
> -       strbuf_add_unique_abbrev(&sb, one, DEFAULT_ABBREV);
> +       strbuf_repo_add_unique_abbrev(&sb, repo, one, DEFAULT_ABBREV);
>         strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
> -       strbuf_add_unique_abbrev(&sb, two, DEFAULT_ABBREV);
> +       strbuf_repo_add_unique_abbrev(&sb, repo, two, DEFAULT_ABBREV);
>         if (message)
>                 strbuf_addf(&sb, " %s\n", message);
>         else
> diff --git a/t/t4041-diff-submodule-option.sh b/t/t4041-diff-submodule-option.sh
> index 4dd4954260..e80472af32 100755
> --- a/t/t4041-diff-submodule-option.sh
> +++ b/t/t4041-diff-submodule-option.sh
> @@ -14,6 +14,24 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
>
>  . ./test-lib.sh
>
> +test_expect_success SHA1 'submodule commit abbreviation uses submodule object database' '
> +       test_when_finished "rm -rf collision-super" &&
> +       git init -q collision-super &&
> +       git init -q collision-super/sm1 &&
> +       printf "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n\nb1rwzyc3\n" >collision-super/sm1/a0blgqsjc &&
> +       git -C collision-super/sm1 add a0blgqsjc &&
> +       tree=$(git -C collision-super/sm1 write-tree) &&
> +       commit1=$(GIT_AUTHOR_DATE="1112911993 -0700" GIT_COMMITTER_DATE="1112911993 -0700" git -C collision-super/sm1 commit-tree "$tree" -m a2onsxbvj) &&
> +       commit2=$(printf "child\n" | GIT_AUTHOR_DATE="1112912053 -0700" GIT_COMMITTER_DATE="1112912053 -0700" git -C collision-super/sm1 commit-tree "$tree" -p "$commit1") &&
> +       git -C collision-super/sm1 checkout -q "$commit2" &&
> +       git -C collision-super update-index --add --cacheinfo 160000,"$commit1",sm1 &&
> +       git -C collision-super commit -q -m "Add submodule" &&
> +       git -C collision-super diff --submodule=log >actual &&
> +       printf "Submodule sm1 0000000000e..%s:\n  > child\n" \
> +               "$(git -C collision-super/sm1 rev-parse --short "$commit2")" >expected &&
> +       test_cmp expected actual
> +'
> +
>  # Test non-UTF-8 encoding in case iconv is available.
>  if test_have_prereq ICONV
>  then
> --
> gitgitgadget
>
Hi Junio,

Thanks for the suggestion.

I've updated the t4041 test to use `test_oid_cache` with separate
expected abbreviations for SHA-1 and SHA-256. I've also removed the
SHA1-only prerequisite so that the test runs with both hash
algorithms.

I tested the updated test script using both configurations:

- SHA-1: all 48 tests passed.
- SHA-256: all 48 tests passed.

I've updated the commit message, added the Signed-off-by trailer, and
submitted the revised v4 patch series.

The updated patch series is available here:
https://lore.kernel.org/git/pull.2288.v4.git.1793648490.gitgitgadget@gmail.com/

Thanks for the suggestion and review.

Regards,
Srujith