From 6f5f1651c7a1f86358929c1ebe404f310f5e6e17 Mon Sep 17 00:00:00 2001
From: Enno Rehling <enno.rehling@gmail.com>
Date: Sun, 9 Sep 2018 07:41:30 +0200
Subject: [PATCH] fix crashes when trying to trade on ocean. fix missing
 message sections.

---
 res/core/messages.xml | 6 +++---
 src/economy.c         | 5 +++--
 src/kernel/region.c   | 5 ++++-
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/res/core/messages.xml b/res/core/messages.xml
index d566c82e6..7e55e05f9 100644
--- a/res/core/messages.xml
+++ b/res/core/messages.xml
@@ -30,7 +30,7 @@
     </type>
   </message>
 
-  <message name="target_region_invalid">
+  <message name="target_region_invalid" section="errors">
     <type>
       <arg name="unit" type="unit"/>
       <arg name="region" type="region"/>
@@ -38,7 +38,7 @@
     </type>
   </message>
   
-  <message name="missing_direction">
+  <message name="missing_direction" section="errors">
     <type>
       <arg name="unit" type="unit"/>
       <arg name="region" type="region"/>
@@ -46,7 +46,7 @@
     </type>
   </message>
   
-  <message name="target_region_not_empty">
+  <message name="target_region_not_empty" section="errors">
     <type>
       <arg name="unit" type="unit"/>
       <arg name="region" type="region"/>
diff --git a/src/economy.c b/src/economy.c
index 3bb7b1066..4a6aa5672 100644
--- a/src/economy.c
+++ b/src/economy.c
@@ -1660,7 +1660,7 @@ static void buy(unit * u, econ_request ** buyorders, struct order *ord)
             return;
         }
     }
-    if (r_demand(r, ltype)) {
+    if (!r->land || r_demand(r, ltype)) {
         ADDMSG(&u->faction->msgs, msg_feedback(u, ord, "luxury_notsold", ""));
         return;
     }
@@ -1702,6 +1702,7 @@ static void expandselling(region * r, econ_request * sellorders, int limit)
     static int bt_cache;
     static const struct building_type *castle_bt, *harbour_bt, *caravan_bt;
 
+    assert(r->land);
     if (bt_changed(&bt_cache)) {
         castle_bt = bt_find("castle");
         harbour_bt = bt_find("harbour");
@@ -1971,7 +1972,7 @@ static bool sell(unit * u, econ_request ** sellorders, struct order *ord)
         econ_request *o;
         int k, available;
 
-        if (!r_demand(r, ltype)) {
+        if (!r->land || !r_demand(r, ltype)) {
             cmistake(u, ord, 263, MSG_COMMERCE);
             return false;
         }
diff --git a/src/kernel/region.c b/src/kernel/region.c
index 7cb52c201..29f7222e1 100644
--- a/src/kernel/region.c
+++ b/src/kernel/region.c
@@ -716,7 +716,10 @@ const item_type *r_luxury(const region * r)
 
 int r_demand(const region * r, const luxury_type * ltype)
 {
-    struct demand *d = r->land->demands;
+    struct demand *d;
+
+    assert(r && r->land);
+    d = r->land->demands;
     while (d && d->type != ltype)
         d = d->next;
     if (!d)