Fixed bug 1636467, sometimes monsters were getting no energy.

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@851 c06c8d41-db1a-0410-9941-cceddc491573

1 files changed, 10 insertions, 2 deletions

diff --git a/crawl-ref/source/monstuff.cc b/crawl-ref/source/monstuff.cc
index afe2e6f91d..7d3c3d8fb3 100644
--- a/crawl-ref/source/monstuff.cc
+++ b/crawl-ref/source/monstuff.cc
@@ -3582,11 +3582,19 @@ static void handle_monster_move(int i, monsters *monster)
         return;
     }
 
-    monster->speed_increment += (monster->speed * you.time_taken) / 10;
+    int energy_gained = (monster->speed * you.time_taken) / 10;
+
+    // Slow monsters might get 0 here. Maybe we should factor in
+    // *how* slow it is...but a 10-to-1 move ratio seems more than
+    // enough.
+    if ( energy_gained == 0 && monster->speed != 0 )
+        energy_gained = 1;
+
+    monster->speed_increment += energy_gained;
 
     if (you.slow > 0)
     {
-        monster->speed_increment += (monster->speed * you.time_taken) / 10;
+        monster->speed_increment += energy_gained;
     }
 
     // Handle enchantments and clouds on nonmoving monsters: