[PATCH] sequencer: ensure labels that are object IDs are rewritten

[PATCH] sequencer: ensure labels that are object IDs are rewritten

[brian m. carlson]

When writing the todo script for --rebase-merges, we try to find a label
for certain commits.  If the label ends up being a valid object ID, such
as when we merge a detached commit, we want to rewrite it so it is no
longer a valid object ID.

However, the code path that does this checks for its length to be
equivalent to GIT_SHA1_RAWSZ, which isn't correct, since what we are
reading is a hex object ID.  Instead, check for the length being
equivalent to that of a hex object ID.  Use the_hash_algo so this code
works regardless of the hash size.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
---

I noticed this while cleaning up a few instances of GIT_SHA1_* constants
and thought I'd send a patch.

 sequencer.c              |  2 +-
 t/t3430-rebase-merges.sh | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/sequencer.c b/sequencer.c
index 1ce63261a3..75ed86a94e 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -3636,7 +3636,7 @@ static const char *label_oid(struct object_id *oid, const char *label,
 				p[i] = save;
 			}
 		}
-	} else if (((len = strlen(label)) == GIT_SHA1_RAWSZ &&
+	} else if (((len = strlen(label)) == the_hash_algo->hexsz &&
 		    !get_oid_hex(label, &dummy)) ||
 		   (len == 1 && *label == '#') ||
 		   hashmap_get_from_hash(&state->labels,
diff --git a/t/t3430-rebase-merges.sh b/t/t3430-rebase-merges.sh
index 3d4dfdf7be..472ad9463c 100755
--- a/t/t3430-rebase-merges.sh
+++ b/t/t3430-rebase-merges.sh
@@ -70,6 +70,7 @@ test_expect_success 'create completely different structure' '
 	merge -C H second
 	merge onebranch # Merge the topic branch '\''onebranch'\''
 	EOF
+	cp script-from-scratch script-from-scratch-orig &&
 	test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
 	test_tick &&
 	git rebase -i -r A &&
@@ -241,4 +242,20 @@ test_expect_success 'refuse to merge ancestors of HEAD' '
 	test_cmp_rev HEAD $before
 '
 
+test_expect_success 'labels that are object IDs are rewritten' '
+	git checkout -b third B &&
+	test_tick &&
+	test_commit I &&
+	third=$(git rev-parse HEAD) &&
+	git checkout -b labels master &&
+	git merge --no-commit third &&
+	test_tick &&
+	git commit -m "Merge commit '\''$third'\'' into labels" &&
+	cp script-from-scratch-orig script-from-scratch &&
+	test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
+	test_tick &&
+	git rebase -i -r A &&
+	! grep "^label $third$" .git/ORIGINAL-TODO
+'
+
 test_done

Re: [PATCH] sequencer: ensure labels that are object IDs are rewritten

[Johannes Schindelin]

Hi Brian,

On Tue, 29 May 2018, brian m. carlson wrote:

> When writing the todo script for --rebase-merges, we try to find a label
> for certain commits.  If the label ends up being a valid object ID, such
> as when we merge a detached commit, we want to rewrite it so it is no
> longer a valid object ID.
> 
> However, the code path that does this checks for its length to be
> equivalent to GIT_SHA1_RAWSZ, which isn't correct, since what we are
> reading is a hex object ID.  Instead, check for the length being
> equivalent to that of a hex object ID.  Use the_hash_algo so this code
> works regardless of the hash size.

D'oh. Thank you so much for this fix.

> I noticed this while cleaning up a few instances of GIT_SHA1_* constants
> and thought I'd send a patch.

You thought well!

> diff --git a/sequencer.c b/sequencer.c
> index 1ce63261a3..75ed86a94e 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -3636,7 +3636,7 @@ static const char *label_oid(struct object_id *oid, const char *label,
>  				p[i] = save;
>  			}
>  		}
> -	} else if (((len = strlen(label)) == GIT_SHA1_RAWSZ &&
> +	} else if (((len = strlen(label)) == the_hash_algo->hexsz &&

Obviously good!

>  		    !get_oid_hex(label, &dummy)) ||
>  		   (len == 1 && *label == '#') ||
>  		   hashmap_get_from_hash(&state->labels,
> diff --git a/t/t3430-rebase-merges.sh b/t/t3430-rebase-merges.sh
> index 3d4dfdf7be..472ad9463c 100755
> --- a/t/t3430-rebase-merges.sh
> +++ b/t/t3430-rebase-merges.sh
> @@ -70,6 +70,7 @@ test_expect_success 'create completely different structure' '
>  	merge -C H second
>  	merge onebranch # Merge the topic branch '\''onebranch'\''
>  	EOF
> +	cp script-from-scratch script-from-scratch-orig &&
>  	test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
>  	test_tick &&
>  	git rebase -i -r A &&
> @@ -241,4 +242,20 @@ test_expect_success 'refuse to merge ancestors of HEAD' '
>  	test_cmp_rev HEAD $before
>  '
>  
> +test_expect_success 'labels that are object IDs are rewritten' '

Thanks for writing a test, I had been meaning to, but it slipped from my
mind.

> +	git checkout -b third B &&
> +	test_tick &&
> +	test_commit I &&

The test_tick before test_commit is unnecessary.

> +	third=$(git rev-parse HEAD) &&
> +	git checkout -b labels master &&
> +	git merge --no-commit third &&
> +	test_tick &&
> +	git commit -m "Merge commit '\''$third'\'' into labels" &&

Here, the test_tick is required because we commit via `git commit`.

BTW another thing that I had been meaning to address but totally forgot is
this '\'' ugliness. I had been meaning to define SQ="'" before all test
cases and then use $SQ everywhere. Not your problem, though.

> +	cp script-from-scratch-orig script-from-scratch &&

There is nothing in that script that you need. Why not simply

	echo noop >script-from-scratch

or if you care about the branch,

	echo reset $third >script-from-scratch

> +	test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
> +	test_tick &&
> +	git rebase -i -r A &&
> +	! grep "^label $third$" .git/ORIGINAL-TODO

I would like to verify in addition that /^label $third-/ is present in
ORIGINAL-TODO, what do you think?

Thank you,
Dscho

Re: [PATCH] sequencer: ensure labels that are object IDs are rewritten

[brian m. carlson]

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On Wed, May 30, 2018 at 11:54:27AM +0200, Johannes Schindelin wrote:
> > +	git checkout -b third B &&
> > +	test_tick &&
> > +	test_commit I &&
> 
> The test_tick before test_commit is unnecessary.

You're right, it is.  Will fix.

> > +	third=$(git rev-parse HEAD) &&
> > +	git checkout -b labels master &&
> > +	git merge --no-commit third &&
> > +	test_tick &&
> > +	git commit -m "Merge commit '\''$third'\'' into labels" &&
> 
> Here, the test_tick is required because we commit via `git commit`.
> 
> BTW another thing that I had been meaning to address but totally forgot is
> this '\'' ugliness. I had been meaning to define SQ="'" before all test
> cases and then use $SQ everywhere. Not your problem, though.
> 
> > +	cp script-from-scratch-orig script-from-scratch &&
> 
> There is nothing in that script that you need. Why not simply
> 
> 	echo noop >script-from-scratch
> 
> or if you care about the branch,
> 
> 	echo reset $third >script-from-scratch

That would be simpler.  You read my mind: I needed some script to make
the sequence editor work, but anything would be fine.

> > +	test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
> > +	test_tick &&
> > +	git rebase -i -r A &&
> > +	! grep "^label $third$" .git/ORIGINAL-TODO
> 
> I would like to verify in addition that /^label $third-/ is present in
> ORIGINAL-TODO, what do you think?

Sure, I can do that.
-- 
brian m. carlson: Houston, Texas, US
OpenPGP: https://keybase.io/bk2204

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Re: [PATCH] sequencer: ensure labels that are object IDs are rewritten

[Johannes Schindelin]

Hi Brian,

On Wed, 30 May 2018, brian m. carlson wrote:

> On Wed, May 30, 2018 at 11:54:27AM +0200, Johannes Schindelin wrote:
> 
> > > +	third=$(git rev-parse HEAD) &&
> > > +	git checkout -b labels master &&
> > > +	git merge --no-commit third &&
> > > +	test_tick &&
> > > +	git commit -m "Merge commit '\''$third'\'' into labels" &&
> > 
> > Here, the test_tick is required because we commit via `git commit`.
> > 
> > BTW another thing that I had been meaning to address but totally forgot is
> > this '\'' ugliness. I had been meaning to define SQ="'" before all test
> > cases and then use $SQ everywhere. Not your problem, though.
> > 
> > > +	cp script-from-scratch-orig script-from-scratch &&
> > 
> > There is nothing in that script that you need. Why not simply
> > 
> > 	echo noop >script-from-scratch
> > 
> > or if you care about the branch,
> > 
> > 	echo reset $third >script-from-scratch
> 
> That would be simpler.  You read my mind: I needed some script to make
> the sequence editor work, but anything would be fine.

I would not go that far. Sometimes I wish I could read minds. More often,
I am glad that I cannot. I simply guessed correctly in this case ;-)

But yes, I think it would not only be simpler, but would also avoid the
head-scratching why the earlier `cp script-from-scratch
script-from-scratch-orig`, and it would also make it more robust to future
changes (e.g. if somebody decides to move test cases around, or introduce
prereqs that skip some).

Ciao,
Dscho

[PATCH v2] sequencer: ensure labels that are object IDs are rewritten

[brian m. carlson]

When writing the todo script for --rebase-merges, we try to find a label
for certain commits.  If the label ends up being a valid object ID, such
as when we merge a detached commit, we want to rewrite it so it is no
longer a valid object ID.

However, the code path that does this checks for its length to be
equivalent to GIT_SHA1_RAWSZ, which isn't correct, since what we are
reading is a hex object ID.  Instead, check for the length being
equivalent to that of a hex object ID.  Use the_hash_algo so this code
works regardless of the hash size.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
---
 sequencer.c              |  2 +-
 t/t3430-rebase-merges.sh | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/sequencer.c b/sequencer.c
index 1ce63261a3..75ed86a94e 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -3636,7 +3636,7 @@ static const char *label_oid(struct object_id *oid, const char *label,
 				p[i] = save;
 			}
 		}
-	} else if (((len = strlen(label)) == GIT_SHA1_RAWSZ &&
+	} else if (((len = strlen(label)) == the_hash_algo->hexsz &&
 		    !get_oid_hex(label, &dummy)) ||
 		   (len == 1 && *label == '#') ||
 		   hashmap_get_from_hash(&state->labels,
diff --git a/t/t3430-rebase-merges.sh b/t/t3430-rebase-merges.sh
index 3d4dfdf7be..9fc4648ff8 100755
--- a/t/t3430-rebase-merges.sh
+++ b/t/t3430-rebase-merges.sh
@@ -241,4 +241,20 @@ test_expect_success 'refuse to merge ancestors of HEAD' '
 	test_cmp_rev HEAD $before
 '
 
+test_expect_success 'labels that are object IDs are rewritten' '
+	git checkout -b third B &&
+	test_commit I &&
+	third=$(git rev-parse HEAD) &&
+	git checkout -b labels master &&
+	git merge --no-commit third &&
+	test_tick &&
+	git commit -m "Merge commit '\''$third'\'' into labels" &&
+	echo noop >script-from-scratch &&
+	test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
+	test_tick &&
+	git rebase -i -r A &&
+	grep "^label $third-" .git/ORIGINAL-TODO &&
+	! grep "^label $third$" .git/ORIGINAL-TODO
+'
+
 test_done

Re: [PATCH v2] sequencer: ensure labels that are object IDs are rewritten

[Johannes Schindelin]

Hi Brian,

On Fri, 1 Jun 2018, brian m. carlson wrote:

> When writing the todo script for --rebase-merges, we try to find a label
> for certain commits.  If the label ends up being a valid object ID, such
> as when we merge a detached commit, we want to rewrite it so it is no
> longer a valid object ID.
> 
> However, the code path that does this checks for its length to be
> equivalent to GIT_SHA1_RAWSZ, which isn't correct, since what we are
> reading is a hex object ID.  Instead, check for the length being
> equivalent to that of a hex object ID.  Use the_hash_algo so this code
> works regardless of the hash size.
> 
> Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>

ACK!
Dscho