--- ray/src/util/rmatrix.c	2021/01/19 23:32:00	2.46
+++ ray/src/util/rmatrix.c	2022/03/03 03:55:13	2.49
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: rmatrix.c,v 2.46 2021/01/19 23:32:00 greg Exp $";
+static const char RCSid[] = "$Id: rmatrix.c,v 2.49 2022/03/03 03:55:13 greg Exp $";
 #endif
 /*
  * General matrix operations.
@@ -209,7 +209,9 @@ rmx_load(const char *inspec, RMPref rmp)
 	RMATRIX		dinfo;
 	RMATRIX		*dnew;
 
-	if (!inspec || !*inspec)
+	if (!inspec)
+		inspec = stdin_name;
+	else if (!*inspec)
 		return(NULL);
 	if (inspec == stdin_name) {		/* reading from stdin? */
 		fp = stdin;
@@ -396,6 +398,23 @@ rmx_write_rgbe(const RMATRIX *rm, FILE *fp)
 	return(1);
 }
 
+/* Check if CIE XYZ primaries were specified */
+static int
+findCIEprims(const char *info)
+{
+	RGBPRIMS	prims;
+
+	if (!info)
+		return(0);
+	info = strstr(info, PRIMARYSTR);
+	if (!info || !primsval(prims, info))
+		return(0);
+
+	return((prims[RED][CIEX] > .99) & (prims[RED][CIEY] < .01) &&
+			(prims[GRN][CIEX] < .01) & (prims[GRN][CIEY] > .99) &&
+			(prims[BLU][CIEX] < .01) & (prims[BLU][CIEY] < .01));
+}
+
 /* Write matrix to file type indicated by dtype */
 int
 rmx_write(const RMATRIX *rm, int dtype, FILE *fp)
@@ -413,7 +432,8 @@ rmx_write(const RMATRIX *rm, int dtype, FILE *fp)
 		fputs(rm->info, fp);
 	if (dtype == DTfromHeader)
 		dtype = rm->dtype;
-	else if ((dtype == DTrgbe) & (rm->dtype == DTxyze))
+	else if (dtype == DTrgbe && (rm->dtype == DTxyze ||
+					findCIEprims(rm->info)))
 		dtype = DTxyze;
 	else if ((dtype == DTxyze) & (rm->dtype == DTrgbe))
 		dtype = DTrgbe;
@@ -433,7 +453,7 @@ rmx_write(const RMATRIX *rm, int dtype, FILE *fp)
 	}
 	if ((dtype == DTfloat) | (dtype == DTdouble))
 		fputendian(fp);			/* important to record */
-	fputformat((char *)cm_fmt_id[dtype], fp);
+	fputformat(cm_fmt_id[dtype], fp);
 	fputc('\n', fp);
 	switch (dtype) {			/* write data */
 	case DTascii: