Merge branch 'jt/submodule-fetch-errmsg'

Error message update.

* jt/submodule-fetch-errmsg:
  submodule: explain first attempt failure clearly

git-submodule.sh

@@ -594,7 +594,7 @@ cmd_update()
 				# is not reachable from a ref.
 				is_tip_reachable "$sm_path" "$sha1" ||
 				fetch_in_submodule "$sm_path" $depth ||
-				say "$(eval_gettext "Unable to fetch in submodule path '\$displaypath'")"
+				say "$(eval_gettext "Unable to fetch in submodule path '\$displaypath'; trying to directly fetch \$sha1:")"
 
 				# Now we tried the usual fetch, but $sha1 may
 				# not be reachable from any of the refs

submodule.c

@@ -1548,6 +1548,13 @@ static int fetch_finish(int retvalue, struct strbuf *err,
 	struct oid_array *commits;
 
 	if (retvalue)
+		/*
+		 * NEEDSWORK: This indicates that the overall fetch
+		 * failed, even though there may be a subsequent fetch
+		 * by commit hash that might work. It may be a good
+		 * idea to not indicate failure in this case, and only
+		 * indicate failure if the subsequent fetch fails.
+		 */
 		spf->result = 1;
 
 	if (!task || !task->sub)