--- rrdtool-1.2.18/src/rrd_graph.c.bak	2007-01-23 22:54:49.000000000 +0200
+++ rrdtool-1.2.18/src/rrd_graph.c	2007-02-03 16:22:25.668458169 +0200
@@ -2550,6 +2550,8 @@ int
 graph_paint(image_desc_t *im, char ***calcpr)
 {
   int i,ii;
+  int ret;
+  char graphtmp[MAXPATH];
   int lazy =     lazy_check(im);
 #ifdef WITH_PIECHART
   int piechart = 0;
@@ -2928,16 +2930,38 @@ graph_paint(image_desc_t *im, char ***ca
     _setmode( _fileno( fo ), O_BINARY );
 #endif
   } else {
-    if ((fo = fopen(im->graphfile,"wb")) == NULL) {
-      rrd_set_error("Opening '%s' for write: %s",im->graphfile,
+    graphtmp[0] = 0;
+    snprintf(graphtmp, MAXPATH - 16, "%s.%u.tmp", im->graphfile, getpid());
+    if ((fo = fopen(graphtmp, "wb")) == NULL) {
+      rrd_set_error("Opening '%s' for write: %s",graphtmp,
                     rrd_strerror(errno));
       return (-1);
     }
   }
-  gfx_render (im->canvas,im->ximg,im->yimg,0x00000000,fo);
-  if (strcmp(im->graphfile,"-") != 0)
-    fclose(fo);
-  return 0;
+  ret = gfx_render (im->canvas,im->ximg,im->yimg,0x00000000,fo);
+  if (fflush(fo) == EOF) {
+    rrd_set_error("fflush '%s': ", graphtmp, rrd_strerror(errno));
+    ret = -1;
+  }
+  if (strcmp(im->graphfile,"-") != 0) {
+#if 0
+    if (fsync(fileno(fo)) == -1) {
+      rrd_set_error("fsync '%s': ", graphtmp, rrd_strerror(errno));
+      ret = -1;
+    }
+#endif
+    if (fclose(fo) == EOF) {
+      rrd_set_error("fclose '%s': ", graphtmp, rrd_strerror(errno));
+      ret = -1;
+    }
+    if (rename(graphtmp, im->graphfile) == -1) {
+      unlink(graphtmp);
+      rrd_set_error("rename '%s' to '%s': ", graphtmp, im->graphfile,
+                    rrd_strerror(errno));
+      ret = -1;
+    }
+  }
+  return ret;
 }