From c986597f1c330c056f9e2baeb60fcf0835f71f45 Mon Sep 17 00:00:00 2001
From: Andrew Johnson <anj@aps.anl.gov>
Date: Wed, 22 Jul 2009 22:58:09 +0000
Subject: [PATCH] Reject breaktables with slope of zero.

---
 src/dbStatic/dbLexRoutines.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/dbStatic/dbLexRoutines.c b/src/dbStatic/dbLexRoutines.c
index b5f969d7c..57461d3a0 100644
--- a/src/dbStatic/dbLexRoutines.c
+++ b/src/dbStatic/dbLexRoutines.c
@@ -872,10 +872,14 @@ static void dbBreakBody(void)
 	double slope =
 	  (paBrkInt[i+1].eng - paBrkInt[i].eng)/
 	  (paBrkInt[i+1].raw - paBrkInt[i].raw);
+	if (!dbBptNotMonotonic && slope == 0) {
+	    yyerrorAbort("breaktable slope is zero");
+	    return;
+	}
 	if (i == 0) {
 	    down = (slope < 0);
 	} else if (!dbBptNotMonotonic && down != (slope < 0)) {
-	    yyerrorAbort("breaktable: curve slope changes sign");
+	    yyerrorAbort("breaktable slope changes sign");
 	    return;
 	}
 	paBrkInt[i].slope = slope;