Merge branch 'jt/reset-grafts-when-resetting-shallow'

When "shallow" information is updated, we forgot to update the
in-core equivalent, which has been corrected.

* jt/reset-grafts-when-resetting-shallow:
  shallow: reset commit grafts when shallow is reset

commit.c

@@ -249,6 +249,16 @@ int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 	return ret;
 }
 
+void reset_commit_grafts(struct repository *r)
+{
+	int i;
+
+	for (i = 0; i < r->parsed_objects->grafts_nr; i++)
+		free(r->parsed_objects->grafts[i]);
+	r->parsed_objects->grafts_nr = 0;
+	r->parsed_objects->commit_graft_prepared = 0;
+}
+
 struct commit_buffer {
 	void *buffer;
 	unsigned long size;

commit.h

@@ -249,6 +249,7 @@ int commit_graft_pos(struct repository *r, const struct object_id *oid);
 int register_commit_graft(struct repository *r, struct commit_graft *, int);
 void prepare_commit_graft(struct repository *r);
 struct commit_graft *lookup_commit_graft(struct repository *r, const struct object_id *oid);
+void reset_commit_grafts(struct repository *r);
 
 struct commit *get_fork_point(const char *refname, struct commit *commit);
 

shallow.c

@@ -90,6 +90,7 @@ static void reset_repository_shallow(struct repository *r)
 {
 	r->parsed_objects->is_shallow = -1;
 	stat_validity_clear(r->parsed_objects->shallow_stat);
+	reset_commit_grafts(r);
 }
 
 int commit_shallow_file(struct repository *r, struct shallow_lock *lk)

submodule.c

@@ -22,6 +22,7 @@
 #include "parse-options.h"
 #include "object-store.h"
 #include "commit-reach.h"
+#include "shallow.h"
 
 static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
 static int initialized_fetch_ref_tips;

t/t5537-fetch-shallow.sh

@@ -161,6 +161,15 @@ test_expect_success 'fetch --update-shallow' '
 	)
 '
 
+test_expect_success 'fetch --update-shallow into a repo with submodules' '
+	git init a-submodule &&
+	test_commit -C a-submodule foo &&
+	git init repo-with-sub &&
+	git -C repo-with-sub submodule add ../a-submodule a-submodule &&
+	git -C repo-with-sub commit -m "added submodule" &&
+	git -C repo-with-sub fetch --update-shallow ../shallow/.git refs/heads/*:refs/remotes/shallow/*
+'
+
 test_expect_success 'fetch --update-shallow (with fetch.writeCommitGraph)' '
 	(
 	cd shallow &&