--- ray/src/util/rmatrix.c	2023/12/08 00:12:31	2.74
+++ ray/src/util/rmatrix.c	2023/12/12 18:45:53	2.76
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: rmatrix.c,v 2.74 2023/12/08 00:12:31 greg Exp $";
+static const char RCSid[] = "$Id: rmatrix.c,v 2.76 2023/12/12 18:45:53 greg Exp $";
 #endif
 /*
  * General matrix operations.
@@ -539,7 +539,9 @@ rmx_write_header(const RMATRIX *rm, int dtype, FILE *f
 		dtype = DTxyze;
 	else if ((dtype == DTxyze) & (rm->dtype == DTrgbe))
 		dtype = DTrgbe;
-	if ((dtype == DTspec) & (rm->ncomp <= 3))
+	if ((dtype < DTspec) & (rm->ncomp > 3))
+		dtype = DTspec;
+	else if ((dtype == DTspec) & (rm->ncomp <= 3))
 		return(0);
 
 	if (dtype == DTascii)			/* set file type (WINDOWS) */
@@ -683,12 +685,16 @@ rmx_transfer_data(RMATRIX *rdst, RMATRIX *rsrc, int do
 		rsrc->info = NULL; rsrc->mapped = NULL; rsrc->mtx = NULL;
 		return(1);
 	}
+#ifdef MAP_FILE			/* just matrix data -- leave metadata */
 	if (rdst->mapped)
-		return(0);	/* XXX can't handle this case */
-				/* just matrix data -- leave metadata */
-	if (rdst->mtx) free(rdst->mtx);
+		munmap(rdst->mapped, mapped_size(rdst));
+	else
+#endif
+	if (rdst->mtx)
+		free(rdst->mtx);
+	rdst->mapped = rsrc->mapped;
 	rdst->mtx = rsrc->mtx;
-	rsrc->mtx = NULL;
+	rsrc->mapped = NULL; rsrc->mtx = NULL;
 	return(1);
 }