From: ian <ian>
Date: Mon, 5 May 2008 10:57:27 +0000 (+0000)
Subject: polarise the interferer too
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ijackson/git?a=commitdiff_plain;h=90330dde6682a428510ac5270c2815cd5280f106;p=trains.git

polarise the interferer too
---

diff --git a/hostside/safety.c b/hostside/safety.c
index a8a58de..d21a05d 100644
--- a/hostside/safety.c
+++ b/hostside/safety.c
@@ -782,8 +782,19 @@ ErrorCode predict(Train *tra, int accelerate,
     }
     if (u.need_polarise && seg->will_polarise) {
       seg->seg_inverted= seg->tr_backwards ^ u.train_polarity_inverted;
-      if (seg->i->invertible) actual_inversions_segment(seg);
-      else assert(!seg->seg_inverted);
+      if (seg->i->invertible) {
+	actual_inversions_segment(seg);
+	Segment *interferer= segment_interferes(0,seg);
+	if (interferer && !interferer->will_polarise &&
+	    interferer->i->invertible) {
+	  /* no provision for interfering invertible segments
+	   * with opposing ideas about neutral polarity */
+	  interferer->seg_inverted= seg->seg_inverted;
+	  actual_inversions_segment(interferer);
+	}
+      } else {
+	assert(!seg->seg_inverted);
+      }
     }
     seg->now_present= seg->pred_present=
       seg->pred_vacated= seg->will_polarise= 0;