cleanupInternalCRLMapping double slash path delete trips up zookeeper backend

[juliantaylor]

the delete on the storage in _cleanupInternalCRLMapping in builtin/logical/pki/issuing/config_revocation.go passes a path with two consecutive slashes to the backend, e.g. when baseCRLPath is "unified-crls/" in the !isLocal case

            if err := s.Delete(ctx, baseCRLPath+"/"+crl); err != nil {
                    return fmt.Errorf("failed cleaning up orphaned CRL %v: %w", crl, err)
            }

While probably no issue for the default backends it trips up the zookeeper one in cleanupLogicalPath

URL: PUT ....:8200/v1/ui/.../root/generate/internal
 
* 1 error occurred:
    * unable to update local CRL config's modification time: error persisting local CRL config: failed to clean up internal CRL mapping: failed cleaning up orphaned CRL c6e199ee-8f9c-18e0-d07b-c541f9c1ff71-delta: failed to acquire node data: zk: invalid path

adding filepath.Clean to the splitting in cleanupLogicalPath (nodes := strings.Split(filepath.Clean(path), "/")) or properly joining in _cleanupInternalCRLMapping fixes the problem

[juliantaylor]

following unittest addition reproduces it:

--- a/sdk/physical/testing.go
+++ b/sdk/physical/testing.go
@@ -154,6 +154,18 @@ func ExerciseBackend(t testing.TB, b Backend) {
                t.Fatalf("failed to remove deep nest: %v", err)
        }
 
+       // Removal duplicated separators should not fail or leave artifacts
+       e = &Entry{Key: "foo/nested1//nested2/nested3", Value: []byte("baz")}
+       err = b.Put(ctx, e)
+       if err != nil {
+               t.Fatalf("deep nest: %v", err)
+       }
+
+       err = b.Delete(ctx, "foo/nested1//nested2/nested3")
+       if err != nil {
+               t.Fatalf("failed to remove deep nest: %v", err)
+       }
+

--- FAIL: TestZooKeeperBackend (0.09s)
    zookeeper_test.go:57: failed to remove deep nest: failed to acquire node data: zk: invalid path