Protection added.

diff --git a/PYTHIA6/pyquen1_5.F b/PYTHIA6/pyquen1_5.F
index 3443e171dc3248018c5b70034170316614600642..f99514005045265551c5c1a3a0ce4aeccea96432 100644 (file)
--- a/PYTHIA6/pyquen1_5.F
+++ b/PYTHIA6/pyquen1_5.F
@@ -1296,8 +1296,9 @@ C************************** END PARINV *************************************
 * if  quark production outside the QGP then 
 * arg=(((dsin(uu)*cosh(uu))**2)+((dcos(uu)*sinh(uu))**2))/(2.d0*uu*uu);   
 * here quark production inside the QGP  
-      arg=((dcos(uu)*cosh(uu))**2)+((dsin(uu)*sinh(uu))**2)   
-      gl1=(ygl/(cfac*z))**0.3333333d0
+      arg=((dcos(uu)*cosh(uu))**2)+((dsin(uu)*sinh(uu))**2)  
+      write(6,*) "Warning in PLFUN1: z < 0.", z
+      gl1=(ygl/(cfac*abs(z)))**0.3333333d0
       gl2=(um/epa)**1.333333d0  
       dc=1.d0/((1.d0+((gl1*gl2*or)**1.5d0))**2)       ! massive parton    
 c      dc=1.d0                                         !massless parton