--- ray/src/rt/rpict.c	1993/07/30 10:31:09	2.26
+++ ray/src/rt/rpict.c	1993/08/06 17:12:19	2.28
@@ -94,7 +94,22 @@ extern char  *mktemp();
 
 double	pixvalue();
 
+#ifdef NIX
+#define  file_exists(f)	(access(f,F_OK)==0)
+#else
+#include  <sys/types.h>
+#include  <sys/stat.h>
+int
+file_exists(fname)				/* ordinary file exists? */
+char  *fname;
+{
+	struct stat  sbuf;
+	if (stat(fname, &sbuf) < 0) return(0);
+	return((sbuf.st_mode & S_IFREG) != 0);
+}
+#endif
 
+
 quit(code)			/* quit program */
 int  code;
 {
@@ -190,12 +205,19 @@ char  *pout, *zout, *prvr;
 				cp--;
 			strcpy(cp, RFTEMPLATE);
 			prvr = mktemp(fbuf2);
-			if (rename(fbuf, prvr) < 0 && errno != ENOENT) {
-				sprintf(errmsg,
+			if (rename(fbuf, prvr) < 0)
+				if (errno == ENOENT) {	/* ghost file */
+					sprintf(errmsg,
+						"new output file \"%s\"",
+						fbuf);
+					error(WARNING, errmsg);
+					prvr = NULL;
+				} else {		/* serious error */
+					sprintf(errmsg,
 					"cannot rename \"%s\" to \"%s\"",
 						fbuf, prvr);
-				error(SYSTEM, errmsg);
-			}
+					error(SYSTEM, errmsg);
+				}
 		}
 	}
 	npicts = 0;			/* render sequence */
@@ -205,8 +227,15 @@ char  *pout, *zout, *prvr;
 		pctdone = 0.0;
 		if (pout != NULL) {
 			sprintf(fbuf, pout, seq);
-			if (prvr == NULL && access(fbuf, F_OK) == 0)
+			if (file_exists(fbuf)) {
+				if (prvr != NULL || !strcmp(fbuf, pout)) {
+					sprintf(errmsg,
+						"output file \"%s\" exists",
+						fbuf);
+					error(USER, errmsg);
+				}
 				continue;		/* don't clobber */
+			}
 			if (freopen(fbuf, "w", stdout) == NULL) {
 				sprintf(errmsg,
 					"cannot open output file \"%s\"", fbuf);