From dca1c45e80aab3e89a555e6cd8b73d6094e22e94 Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Sun, 16 Aug 2020 06:40:49 -0700
Subject: [PATCH] SCP: Assure that library unit tests are run under reasonable
 conditions.

---
 scp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/scp.c b/scp.c
index 56de4c7a..7c3b4257 100644
--- a/scp.c
+++ b/scp.c
@@ -15509,6 +15509,10 @@ int32 saved_switches = sim_switches & ~SWMASK ('T');
 t_stat stat = SCPE_OK;
 char gbuf[CBUFSIZE];
 
+if (sim_time != 0.0)
+    return sim_messagef (SCPE_UNK, "Library tests can not be performed after instructions have been executed.\n");
+detach_all (0, 0);                          /* Assure that all units are unattached */
+
 cptr = get_glyph (cptr, gbuf, 0);
 if (gbuf[0] == '\0')
     strcpy (gbuf, "ALL");