Re: [PATCH] remote: Ignore failure to remove missing branch.<name>.merge

[Junio C Hamano <gitster@pobox.com>]

Ross Lagerwall <rosslagerwall@gmail.com> writes:

> If a branch is configured with a default remote but no
> branch.<name>.merge and then the remote is removed, git fails to remove
> the remote with:
> "fatal: could not unset 'branch.<name>.merge'"
>
> Instead, ignore this since it is not an error and shouldn't prevent the
> remote from being removed.
>
> Signed-off-by: Ross Lagerwall <rosslagerwall@gmail.com>
> ---

I was waiting for others to comment on this patch but nobody seems
to be interested.  Which is a bit sad, because except for minor
nits, this patch is very well done.

The explanation of the motivation and solution in the proposed log
message is excellent.  It would have been perfect if you described
HOW you get into a state where branch.<name>.remote is pointing at
the remote being removed, without having branch.<name>.merge in the
first place, but even if such a state is invalid or unplausible,
removing the remote should be a usable way to recover from such a
situation.

And the proposed solution in the diff seems to correctly implement
what the description of the solution in the log message (modulo a
minor nit).

>  builtin/remote.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/builtin/remote.c b/builtin/remote.c
> index e52cf3925..5dd22c2eb 100644
> --- a/builtin/remote.c
> +++ b/builtin/remote.c
> @@ -769,7 +769,9 @@ static int rm(int argc, const char **argv)
>  				strbuf_reset(&buf);
>  				strbuf_addf(&buf, "branch.%s.%s",
>  						item->string, *k);
> -				git_config_set(buf.buf, NULL);
> +				result = git_config_set_gently(buf.buf, NULL);
> +				if (result && result != CONFIG_NOTHING_SET)
> +					die(_("COULd not unset '%s'"), buf.buf);

With s/COUL/coul/, the result would be more in line with our
existing practice.

>  			}
>  		}
>  	}

We do want an additional test so that this fix will not be broken
again in the future by mistake, perhaps in t5505.

As it is unclear to me how you got into a state where branch.*.remote
exists without branch.*.merge, the attached patch to the test manually
removes it, which probably falls into a "deliberate sabotage" category.
If there are a valid sequence of operations that leads to such a state
without being a deliberate sabotage, we should use it instead in the
real test.

Thanks.

 builtin/remote.c  |  4 +++-
 t/t5505-remote.sh | 19 +++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/builtin/remote.c b/builtin/remote.c
index e52cf3925b..01055b7272 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -769,7 +769,9 @@ static int rm(int argc, const char **argv)
 				strbuf_reset(&buf);
 				strbuf_addf(&buf, "branch.%s.%s",
 						item->string, *k);
-				git_config_set(buf.buf, NULL);
+				result = git_config_set_gently(buf.buf, NULL);
+				if (result && result != CONFIG_NOTHING_SET)
+					die(_("could not unset '%s'"), buf.buf);
 			}
 		}
 	}
diff --git a/t/t5505-remote.sh b/t/t5505-remote.sh
index 8198d8eb05..af85a624fc 100755
--- a/t/t5505-remote.sh
+++ b/t/t5505-remote.sh
@@ -153,6 +153,25 @@ test_expect_success 'remove errors out early when deleting non-existent branch'
 	)
 '
 
+test_expect_success 'remove remote with a branch without configured merge' '
+	test_when_finished "(
+		git -C test checkout master;
+		git -C test branch -D two;
+		git -C test config --remove-section remote.two;
+		git -C test config --remove-section branch.second;
+		true
+	)" &&
+	(
+		cd test &&
+		git remote add two ../two &&
+		git fetch two &&
+		git checkout -t -b second two/master &&
+		git checkout master &&
+		git config --unset branch.second.merge &&
+		git remote rm two
+	)
+'
+
 test_expect_success 'rename errors out early when deleting non-existent branch' '
 	(
 		cd test &&