Fix wrong sanity check.

When comparing if we use the same read and write storage in migrations
and copies we should ignore any autochanger devices as its fine to use
those as both read and write device.

src/dird/migrate.c

@@ -365,6 +365,24 @@ static bool set_migration_next_pool(JCR *jcr, POOLRES **retpool)
    return true;
 }
 
+/*
+ * Sanity check that we are not using the same storage for reading and writing.
+ */
+static inline bool same_storage(JCR *jcr)
+{
+   STORERES *read_store, *write_store;
+
+   read_store = (STORERES *)jcr->rstorage->first();
+   write_store = (STORERES *)jcr->wstorage->first();
+
+   if (!read_store->autochanger && !write_store->autochanger &&
+       bstrcmp(read_store->name(), write_store->name())) {
+      return true;
+   }
+
+   return false;
+}
+
 /*
  * Do a Migration of a previous job
  *
@@ -403,9 +421,18 @@ bool do_migration(JCR *jcr)
    if (jcr->previous_jr.JobType != JT_BACKUP &&
        jcr->previous_jr.JobType != JT_JOB_COPY) {
       Jmsg(jcr, M_INFO, 0, _("JobId %s already %s probably by another Job. %s stopped.\n"),
-         edit_int64(jcr->previous_jr.JobId, ed1),
-         jcr->get_ActionName(true),
-         jcr->get_OperationName());
+           edit_int64(jcr->previous_jr.JobId, ed1),
+           jcr->get_ActionName(true),
+           jcr->get_OperationName());
+      jcr->setJobStatus(JS_Terminated);
+      migration_cleanup(jcr, jcr->JobStatus);
+      return true;
+   }
+
+   if (same_storage(jcr)) {
+      Jmsg(jcr, M_FATAL, 0, _("JobId %s cannot %s using the same read and write storage.\n"),
+           edit_int64(jcr->previous_jr.JobId, ed1),
+           jcr->get_OperationName());
       jcr->setJobStatus(JS_Terminated);
       migration_cleanup(jcr, jcr->JobStatus);
       return true;