From 38d377f4c43fa5493f32605209a5e8760216647f Mon Sep 17 00:00:00 2001
From: lethosor <lethosor@gmail.com>
Date: Tue, 23 Jun 2015 21:21:21 -0400
Subject: [PATCH] Fix a few zone plugin crashes

* Avoid checking building types of null pointers
* Detect selected cages properly

Fixes #646
---
 plugins/zone.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/plugins/zone.cpp b/plugins/zone.cpp
index 2f28a0e48..10ffcd3c8 100644
--- a/plugins/zone.cpp
+++ b/plugins/zone.cpp
@@ -601,12 +601,12 @@ void unitInfo(color_ostream & out, df::unit* unit, bool verbose = false)
 
 bool isCage(df::building * building)
 {
-    return building->getType() == building_type::Cage;
+    return building && (building->getType() == building_type::Cage);
 }
 
 bool isChain(df::building * building)
 {
-    return building->getType() == building_type::Chain;
+    return building && (building->getType() == building_type::Chain);
 }
 
 // returns building of cage at cursor position (NULL if nothing found)
@@ -2004,7 +2004,7 @@ command_result df_zone (color_ostream &out, vector <string> & parameters)
         // cagezone wants a pen/pit as starting point
         if(!cagezone_assign)
             target_building = findCageAtCursor();
-        if(!target_building)
+        if(target_building)
         {
             out << "Target building type: cage." << endl;
         }