pvscan: fix segfault in recent commit

commit aa75b31db5478
  "pvscan: handle case of scanning PV without metadata last"

failed to recognize that an arg may be null in the case of
'pvscan --cache' (without -aay) which does not keep track
of complete VGs because it does not need to activate them.

diff --git a/tools/pvscan.c b/tools/pvscan.c
index e389106542ccd672ef92749cd117c809741924b7..6d8942625656f47e8503d2f75b35421dfe4ace45 100644 (file)
--- a/tools/pvscan.c
+++ b/tools/pvscan.c
@@ -759,6 +759,10 @@ static void _check_vg_with_pvid_complete(struct cmd_context *cmd,
  *
  * . When dev_args is set, then complete VGs that that contain
  *   devs in dev_args will be returned in found_vgnames.
+ *
+ * found_vgnames is null for 'pvscan --cache' (without -aay)
+ * since the command does not need to keep track of complete
+ * vgs since it does not need to activate them.
  */
 
 static void _online_pvscan_all_devs(struct cmd_context *cmd,
@@ -794,7 +798,7 @@ static void _online_pvscan_all_devs(struct cmd_context *cmd,
                }
 
                /* This PV without metadata may complete a VG. */
-               if (pvid_without_metadata)
+               if (pvid_without_metadata && found_vgnames)
                        _check_vg_with_pvid_complete(cmd, found_vgnames, &all_vgs, pvid_without_metadata);
        }