From 43a0368fb4ead71e8402115bf0575e00aa58778a Mon Sep 17 00:00:00 2001
From: Enno Rehling <enno.rehling@gmail.com>
Date: Thu, 24 Sep 2020 20:12:51 +0200
Subject: [PATCH] lighthouses protect from drifting

do not check for maintenance in update_lighthouse, but when the lighthouse is used.
---
 src/lighthouse.c      | 29 ++++++++++++++++++++---------
 src/lighthouse.test.c |  5 +++--
 2 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/src/lighthouse.c b/src/lighthouse.c
index 7915bdf44..257836d20 100644
--- a/src/lighthouse.c
+++ b/src/lighthouse.c
@@ -21,7 +21,12 @@ attrib_type at_lighthouse = {
 
 bool is_lighthouse(const building_type *btype)
 {
-    return is_building_type(btype, "lighthouse");
+    static int config;
+    static const building_type *bt_lighthouse;
+    if (bt_changed(&config)) {
+        bt_lighthouse = bt_find("lighthouse");
+    }
+    return btype == bt_lighthouse;
 }
 
 /* update_lighthouse: call this function whenever the size of a lighthouse changes
@@ -81,7 +86,7 @@ void remove_lighthouse(const building *lh) {
 
 int lighthouse_range(const building * b)
 {
-    if (b->size >= 10 && (b->flags & BLD_MAINTAINED)) {
+    if (b->size >= 10) {
         return (int)log10(b->size) + 1;
     }
     return 0;
@@ -112,13 +117,19 @@ bool lighthouse_guarded(const region * r)
     for (a = a_find(r->attribs, &at_lighthouse); a && a->type == &at_lighthouse;
         a = a->next) {
         building *b = (building *)a->data.v;
-
-        assert(is_building_type(b->type, "lighthouse"));
-        if ((b->flags & BLD_MAINTAINED) && b->size >= 10) {
-            int maxd = (int)log10(b->size) + 1;
-            int d = distance(r, b->region);
-            assert(maxd >= d);
-            return true;
+        if (b->flags & BLD_MAINTAINED) {
+            if (r == b->region) {
+                return true;
+            }
+            else {
+                int maxd = lighthouse_range(b);
+                if (maxd > 0) {
+                    int d = distance(r, b->region);
+                    if (maxd >= d) {
+                        return true;
+                    }
+                }
+            }
         }
     }
 
diff --git a/src/lighthouse.test.c b/src/lighthouse.test.c
index 9dc6d2999..8230b97f2 100644
--- a/src/lighthouse.test.c
+++ b/src/lighthouse.test.c
@@ -30,8 +30,6 @@ static void test_lighthouse_range(CuTest * tc)
     b->size = 9;
     CuAssertIntEquals(tc, 0, lighthouse_range(b));
     b->size = 10;
-    CuAssertIntEquals(tc, 0, lighthouse_range(b));
-    b->flags |= BLD_MAINTAINED;
     CuAssertIntEquals(tc, 2, lighthouse_range(b));
     u1->building = b;
     u2->building = b;
@@ -39,6 +37,8 @@ static void test_lighthouse_range(CuTest * tc)
     set_level(u1, SK_PERCEPTION, 3);
     set_level(u2, SK_PERCEPTION, 3);
 
+    CuAssertIntEquals(tc, 0, lighthouse_view_distance(b, u1));
+    b->flags |= BLD_MAINTAINED;
     CuAssertIntEquals(tc, 1, lighthouse_view_distance(b, u1));
     set_level(u1, SK_PERCEPTION, 6);
     CuAssertIntEquals(tc, 1, lighthouse_view_distance(b, u2));
@@ -126,6 +126,7 @@ static void test_lighthouse_guard(CuTest * tc) {
     CuAssertIntEquals(tc, true, lighthouse_guarded(r3));
     CuAssertIntEquals(tc, false, lighthouse_guarded(r4));
     b->size = 1; /* size can go down in destroy_cmd */
+    update_lighthouse(b);
     CuAssertIntEquals(tc, false, lighthouse_guarded(r2));
     CuAssertIntEquals(tc, false, lighthouse_guarded(r3));
     test_teardown();