Fix fgets handling.

1. Skip blank lines instead of dereferencing NULL-1.
2. If bufr is a blank line don't pass bufr+1 as a pointer.

OK millert

1 files changed, 11 insertions, 8 deletions

diff --git a/games/hack/hack.pager.c b/games/hack/hack.pager.c
index 507371d2c93..553a8ad9e45 100644
--- a/games/hack/hack.pager.c
+++ b/games/hack/hack.pager.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hack.pager.c,v 1.15 2009/06/01 09:07:56 ray Exp $	*/
+/*	$OpenBSD: hack.pager.c,v 1.16 2009/06/01 22:57:14 ray Exp $	*/
 
 /*
  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
@@ -62,7 +62,7 @@
  */
 
 #ifndef lint
-static const char rcsid[] = "$OpenBSD: hack.pager.c,v 1.15 2009/06/01 09:07:56 ray Exp $";
+static const char rcsid[] = "$OpenBSD: hack.pager.c,v 1.16 2009/06/01 22:57:14 ray Exp $";
 #endif /* not lint */
 
 /* This file contains the command routine dowhatis() and a pager. */
@@ -87,6 +87,7 @@ dowhatis()
 	FILE *fp;
 	char bufr[BUFSZ+6];
 	char *buf = &bufr[6], *ep, q;
+	size_t len;
 	extern char readchar();
 
 	if (!(fp = fopen(DATAFILE, "r")))
@@ -97,18 +98,20 @@ dowhatis()
 		if (q != '\t')
 			while (fgets(buf,BUFSZ,fp))
 				if (*buf == q) {
-					ep = strchr(buf, '\n');
-					if (ep)
-						*ep = 0;
-					/* else: bad data file */
+					len = strcspn(buf, "\n");
+					/* bad data file */
+					if (len == 0)
+						continue;
+					buf[len] = '\0';
 					/* Expand tab 'by hand' */
 					if (buf[1] == '\t'){
 						buf = bufr;
 						buf[0] = q;
 						(void) strncpy(buf+1, "       ", 7);
+						len = strlen(buf);
 					}
 					pline(buf);
-					if (ep[-1] == ';') {
+					if (buf[len - 1] == ';') {
 						pline("More info? ");
 						if (readchar() == 'y') {
 							page_more(fp,1); /* does fclose() */
@@ -146,7 +149,7 @@ page_more(FILE *fp, int strip)
 	while (fgets(bufr, CO, fp) && (!strip || *bufr == '\t') &&
 	    !got_intrup) {
 		bufr[strcspn(bufr, "\n")] = '\0';
-		if(page_line(bufr+strip)) {
+		if (*bufr == '\0' || page_line(bufr+strip)) {
 			set_pager(2);
 			goto ret;
 		}