Subject: [PATCH] git-submodule.sh: try harder to fetch a submodule

From: Stefan Beller <[email-masked]>
Date: Tue, 15 May 2018 13:00:26 -0700

This is the logical continuum of fb43e31f2b4 (submodule: try harder to
fetch needed sha1 by direct fetching sha1, 2016-02-23) and fixes it as
some assumptions were not correct.

The commit states:
> If $sha1 was not part of the default fetch ... fail ourselves here
> assumes that the fetch_in_submodule only fails when the serverside does
> not support fetching by sha1.

There are other failures, why such a fetch may fail, such as
    fatal: Couldn't find remote ref HEAD
which can happen if the remote side doesn't advertise HEAD and we do not
have a local fetch refspec.

Not advertising HEAD is allowed by the protocol spec and would happen,
if HEAD points at an unborn branch for example.

Not having a local fetch refspec can happen when submodules are fetched
shallowly, as then git-clone doesn't setup a fetch refspec.

So do try even harder for a submodule by ignoring the exit code of the
first fetch and rather relying on the following is_tip_reachable to
see if we try fetching again.

Signed-off-by: Stefan Beller <[email-masked]>
---
 git-submodule.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index 24914963ca2..00fcd69138f 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -614,7 +614,7 @@ cmd_update()
 				# is not reachable from a ref.
 				is_tip_reachable "$sm_path" "$sha1" ||
 				fetch_in_submodule "$sm_path" $depth ||
-				die "$(eval_gettext "Unable to fetch in submodule path '\$displaypath'")"
+				say "$(eval_gettext "Unable to fetch in submodule path '\$displaypath'")"
 
 				# Now we tried the usual fetch, but $sha1 may
 				# not be reachable from any of the refs
-- 
2.17.0.582.gccdcbd54c44.dirty