[PATCH] fetch: don't try to update unfetched tracking refs

Since commit f269048 (fetch: opportunistically update tracking refs,
2013-05-11) we update tracking refs opportunistically when fetching
remote branches.  However, if a refspec is given on the command line
that does not include a configured (non-pattern) refspec a fatal error
occurs.

Fix this by setting the "missing_ok" flag when calling get_fetch_map.

Signed-off-by: John Keeping <redacted>
---
 builtin/fetch.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/builtin/fetch.c b/builtin/fetch.c
index e41cc0d..d15a734 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c

@@ -183,7 +183,7 @@ static struct ref *get_ref_map(struct transport *transport,
 		old_tail = tail;
 		for (i = 0; i < transport->remote->fetch_refspec_nr; i++)
 			get_fetch_map(ref_map, &transport->remote->fetch[i],
-				      &tail, 0);
+				      &tail, 1);
 		for (rm = *old_tail; rm; rm = rm->next)
 			rm->fetch_head_status = FETCH_HEAD_IGNORE;
 	} else {

-- 
1.8.3.rc3.438.gb3e4ae3

On Mon, May 27, 2013 at 12:40:25PM +0100, John Keeping wrote:

Since commit f269048 (fetch: opportunistically update tracking refs,
2013-05-11) we update tracking refs opportunistically when fetching
remote branches.  However, if a refspec is given on the command line
that does not include a configured (non-pattern) refspec a fatal error
occurs.

I'm not sure I understand what the last sentence means. I tried to add a
test like:

diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index ff43e08..02e30e1 100755
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh

@@ -422,6 +422,16 @@ test_expect_success 'configured fetch updates tracking' '
 	)
 '
 
+test_expect_success 'non-configured ref does not confuse tracking update' '
+	cd "$D" &&
+	git update-ref refs/odd/location HEAD &&
+	(
+		cd three &&
+		git fetch origin refs/odd/location &&
+		git rev-parse --verify FETCH_HEAD
+	)
+'
+
 test_expect_success 'pushing nonexistent branch by mistake should not segv' '
 
 	cd "$D" &&

but it does not fail with the existing code. Can you give an example
that fails?

-Peff

On Mon, May 27, 2013 at 11:42:52AM -0400, Jeff King wrote:

I have this in my .git/config for git.git:

    [remote "origin"]
            url = git://github.com/gitster/git
            fetch = +refs/heads/*:refs/remotes/origin/*
            fetch = +refs/notes/amlog:refs/notes/amlog

Then doing "git fetch origin master" fails because:

    fatal: Couldn't find remote ref refs/notes/amlog

The following test fails for me (and passes with my patch) - note that
in "two", remote.one.fetch is configured as
"refs/heads/master:refs/heads/one".

-- >8 --

diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index ff43e08..c540257 100755
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh

@@ -422,6 +422,19 @@ test_expect_success 'configured fetch updates tracking' '
 	)
 '
 
+test_expect_success 'configured ref does not confuse tracking' '
+
+	cd "$D" &&
+	(
+		cd one &&
+		git branch -f side
+	) &&
+	(
+		cd two &&
+		git fetch one side
+	)
+'
+
 test_expect_success 'pushing nonexistent branch by mistake should not segv' '
 
 	cd "$D" &&

On Mon, May 27, 2013 at 05:01:29PM +0100, John Keeping wrote:

quoted

I'm not sure I understand what the last sentence means. I tried to add a
test like:

[...]

quoted

but it does not fail with the existing code. Can you give an example
that fails?

I have this in my .git/config for git.git:

    [remote "origin"]
            url = git://github.com/gitster/git
            fetch = +refs/heads/*:refs/remotes/origin/*
            fetch = +refs/notes/amlog:refs/notes/amlog

Ah, I see. It is not "the refspec on the command-line does not match a
configured refspec", but rather "there exists a configured non-pattern
refspec that does not match what was on the command-line (even if what
was on the command-line did match another refspec)".

So your fix makes perfect sense. Do you mind squashing in this test
below? I think it is a little less subtle than what you posted, as it
sets up the situation explicitly in the test. It also checks that the
refs we _did_ match still get updated ("master" in this case).

diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index ff43e08..fde6891 100755
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh

@@ -422,6 +422,22 @@ test_expect_success 'configured fetch updates tracking' '
 	)
 '
 
+test_expect_success 'non-matching refspecs do not confuse tracking update' '
+	cd "$D" &&
+	git update-ref refs/odd/location HEAD &&
+	(
+		cd three &&
+		git update-ref refs/remotes/origin/master base-origin-master &&
+		git config --add remote.origin.fetch \
+			refs/odd/location:refs/remotes/origin/odd &&
+		o=$(git rev-parse --verify refs/remotes/origin/master) &&
+		git fetch origin master &&
+		n=$(git rev-parse --verify refs/remotes/origin/master) &&
+		test "$o" != "$n" &&
+		test_must_fail git rev-parse --verify refs/remotes/origin/odd
+	)
+'
+
 test_expect_success 'pushing nonexistent branch by mistake should not segv' '
 
 	cd "$D" &&

Thanks for the fix.

Acked-by: Jeff King <redacted>

-Peff

Since commit f269048 (fetch: opportunistically update tracking refs,
2013-05-11) we update tracking refs opportunistically when fetching
remote branches.  However, if there is a configured non-pattern refspec
that does not match any of the refspecs given on the command line then a
fatal error occurs.

Fix this by setting the "missing_ok" flag when calling get_fetch_map.

Test-added-by: Jeff King [off-list ref]
Signed-off-by: John Keeping <redacted>
Acked-by: Jeff King <redacted>
---
On Mon, May 27, 2013 at 12:19:34PM -0400, Jeff King wrote:

On Mon, May 27, 2013 at 05:01:29PM +0100, John Keeping wrote:

quoted

quoted

I'm not sure I understand what the last sentence means. I tried to add a
test like:

[...]

quoted

but it does not fail with the existing code. Can you give an example
that fails?

I have this in my .git/config for git.git:

    [remote "origin"]
            url = git://github.com/gitster/git
            fetch = +refs/heads/*:refs/remotes/origin/*
            fetch = +refs/notes/amlog:refs/notes/amlog

Ah, I see. It is not "the refspec on the command-line does not match a
configured refspec", but rather "there exists a configured non-pattern
refspec that does not match what was on the command-line (even if what
was on the command-line did match another refspec)".

Exactly.  I've changed the commit message to (hopefully) make this
clearer.

So your fix makes perfect sense. Do you mind squashing in this test
below? I think it is a little less subtle than what you posted, as it
sets up the situation explicitly in the test. It also checks that the
refs we _did_ match still get updated ("master" in this case).

Done.

 builtin/fetch.c  |  2 +-
 t/t5510-fetch.sh | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/builtin/fetch.c b/builtin/fetch.c
index e41cc0d..d15a734 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c

@@ -183,7 +183,7 @@ static struct ref *get_ref_map(struct transport *transport,
 		old_tail = tail;
 		for (i = 0; i < transport->remote->fetch_refspec_nr; i++)
 			get_fetch_map(ref_map, &transport->remote->fetch[i],
-				      &tail, 0);
+				      &tail, 1);
 		for (rm = *old_tail; rm; rm = rm->next)
 			rm->fetch_head_status = FETCH_HEAD_IGNORE;
 	} else {

diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index ff43e08..fde6891 100755
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh

@@ -422,6 +422,22 @@ test_expect_success 'configured fetch updates tracking' '
 	)
 '
 
+test_expect_success 'non-matching refspecs do not confuse tracking update' '
+	cd "$D" &&
+	git update-ref refs/odd/location HEAD &&
+	(
+		cd three &&
+		git update-ref refs/remotes/origin/master base-origin-master &&
+		git config --add remote.origin.fetch \
+			refs/odd/location:refs/remotes/origin/odd &&
+		o=$(git rev-parse --verify refs/remotes/origin/master) &&
+		git fetch origin master &&
+		n=$(git rev-parse --verify refs/remotes/origin/master) &&
+		test "$o" != "$n" &&
+		test_must_fail git rev-parse --verify refs/remotes/origin/odd
+	)
+'
+
 test_expect_success 'pushing nonexistent branch by mistake should not segv' '
 
 	cd "$D" &&

-- 
1.8.3.rc3.438.gb3e4ae3

On Mon, May 27, 2013 at 05:33:09PM +0100, John Keeping wrote:

quoted

Ah, I see. It is not "the refspec on the command-line does not match a
configured refspec", but rather "there exists a configured non-pattern
refspec that does not match what was on the command-line (even if what
was on the command-line did match another refspec)".

Exactly.  I've changed the commit message to (hopefully) make this
clearer.

It does. To me, anyway. :)

Thanks again.

-Peff