From e9ffce0200246e9bd1d31ed140bc8b62ee39270f Mon Sep 17 00:00:00 2001
From: wolfgangb <wolfgangb@837edb03-e0f3-0310-88ca-d4d4e8b29345>
Date: Sun, 30 Aug 2009 12:10:24 +0000
Subject: [PATCH] Patch by Matt McCutchen to prevent division by zero when Tux
 spawns exactly at a willowisp. (Bug 490)

git-svn-id: http://supertux.lethargik.org/svn/supertux/trunk/supertux@5910 837edb03-e0f3-0310-88ca-d4d4e8b29345
---
 src/badguy/willowisp.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/badguy/willowisp.cpp b/src/badguy/willowisp.cpp
index 0e55486f1..db467e7f9 100644
--- a/src/badguy/willowisp.cpp
+++ b/src/badguy/willowisp.cpp
@@ -106,11 +106,14 @@ WillOWisp::active_update(float elapsed_time)
     break;
 
   case STATE_TRACKING:
-    if (dist.norm() <= vanish_range) {
+    if (dist.norm() > vanish_range) {
+      vanish();
+    } else if (dist.norm() >= 1) {
       Vector dir = dist.unit();
       movement = dir * elapsed_time * flyspeed;
     } else {
-      vanish();
+      /* We somehow landed right on top of the player without colliding.
+       * Sit tight and avoid a division by zero. */
     }
     sound_source->set_position(get_pos());
     break;
-- 
2.11.0