--- ray/src/rt/m_alias.c	2003/09/09 03:28:43	2.3
+++ ray/src/rt/m_alias.c	2006/07/12 05:47:05	2.6
@@ -1,13 +1,15 @@
 #ifndef lint
-static const char RCSid[] = "$Id: m_alias.c,v 2.3 2003/09/09 03:28:43 greg Exp $";
+static const char RCSid[] = "$Id: m_alias.c,v 2.6 2006/07/12 05:47:05 greg Exp $";
 #endif
 /*
  * Handler for modifier alias
  */
 
 #include "copyright.h"
+
 #include "ray.h"
 #include "otypes.h"
+#include "rtotypes.h"
 #include "otspecial.h"
 
 /*
@@ -21,23 +23,35 @@ static const char RCSid[] = "$Id: m_alias.c,v 2.3 2003
  *  chain at all.
  */
 
-int
-m_alias(m, r)			/* transfer shading to alias target */
-OBJREC	*m;
-RAY	*r;
+extern int
+m_alias(			/* transfer shading to alias target */
+	OBJREC	*m,
+	RAY	*r
+)
 {
 	OBJECT	aobj;
+	OBJREC	*aop;
 	OBJREC	arec;
+	int	rval;
 					/* straight replacement? */
 	if (!m->oargs.nsargs)
 		return(rayshade(r, m->omod));
 					/* else replace alias */
 	if (m->oargs.nsargs != 1)
 		objerror(m, INTERNAL, "bad # string arguments");
-	aobj = lastmod(objndx(m), m->oargs.sarg[0]);
-	if (aobj < 0)
-		objerror(m, USER, "bad reference");
-	arec = *objptr(aobj);
+	aop = m;
+	aobj = objndx(aop);
+	do {				/* follow alias trail */
+		if (aop->oargs.nsargs == 1)
+			aobj = lastmod(aobj, aop->oargs.sarg[0]);
+		else
+			aobj = aop->omod;
+		if (aobj < 0)
+			objerror(aop, USER, "bad reference");
+		aop = objptr(aobj);
+	} while (aop->otype == MOD_ALIAS);
+					/* copy struct */
+	arec = *aop;
 					/* irradiance hack */
 	if (do_irrad && !(r->crtype & ~(PRIMARY|TRANS)) &&
 			m->otype != MAT_CLIP &&
@@ -52,5 +66,12 @@ RAY	*r;
 					/* substitute modifier */
 	arec.omod = m->omod;
 					/* replacement shader */
-	return((*ofun[arec.otype].funp)(&arec, r));
+	rval = (*ofun[arec.otype].funp)(&arec, r);
+					/* save allocated struct */
+	if (arec.os != aop->os) {
+		if (aop->os != NULL)	/* should never happen */
+			free_os(aop);
+		aop->os = arec.os;
+	}
+	return(rval);
 }