From: ellson <devnull@localhost>
Date: Tue, 3 Oct 2006 20:23:35 +0000 (+0000)
Subject: improve arithmetic limit fix
X-Git-Tag: LAST_LIBGRAPH~32^2~5840
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6a246eef318f063949bc700dc3e2aa3b8dac0b93;p=graphviz

improve arithmetic limit fix
---

diff --git a/lib/common/geom.c b/lib/common/geom.c
index 0c4bb3b05..a76e02686 100644
--- a/lib/common/geom.c
+++ b/lib/common/geom.c
@@ -527,6 +527,7 @@ double ptToLine2 (pointf a, pointf b, pointf p)
   double dx = b.x-a.x;
   double dy = b.y-a.y;
   double a2 = (p.y-a.y)*dx - (p.x-a.x)*dy;
-  if (a2 < .00001) return 0.;
-  return (a2*a2) / (dx*dx + dy*dy);
+  a2 *= a2;   /* square - ensures that it is positive */
+  if (a2 < .00001) return 0.;  /* avoid 0/0 problems */
+  return a2 / (dx*dx + dy*dy);
 }