Index: read.c
===================================================================
--- read.c	(revision 30797)
+++ read.c	(revision 30798)
@@ -2594,6 +2594,7 @@
 	gds_init(&tag);
 	while ((c = fgetc(f)) != EOF) {
 		pos++;
+		if (pos > 1024) break; /* header must be in the first kilobyte */
 		switch (state) {
 		case ST_WS:
 			if (isspace(c))