From: Gurusamy Sarathy <gsar@cpan.org>
Date: Sun, 5 Sep 1999 22:28:57 +0000 (+0000)
Subject: fix data loss when more than one block is read from SDBM
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=98627ae8f09f88a753760c651828da353f8c4989;p=p5sagit%2Fp5-mst-13.2.git

fix data loss when more than one block is read from SDBM
*.dir file (suggested by Uwe Ohse <uwe@ohse.de>)

p4raw-id: //depot/perl@4082
---

diff --git a/ext/SDBM_File/sdbm/sdbm.c b/ext/SDBM_File/sdbm/sdbm.c
index 499871d..5952d71 100644
--- a/ext/SDBM_File/sdbm/sdbm.c
+++ b/ext/SDBM_File/sdbm/sdbm.c
@@ -431,9 +431,12 @@ getdbit(register DBM *db, register long int dbit)
 	dirb = c / DBLKSIZ;
 
 	if (dirb != db->dirbno) {
+		int got;
 		if (lseek(db->dirf, OFF_DIR(dirb), SEEK_SET) < 0
-		    || read(db->dirf, db->dirbuf, DBLKSIZ) < 0)
+		    || (got=read(db->dirf, db->dirbuf, DBLKSIZ)) < 0)
 			return 0;
+		if (got==0) 
+			memset(db->dirbuf,0,DBLKSIZ);
 		db->dirbno = dirb;
 
 		debug(("dir read: %d\n", dirb));
@@ -452,10 +455,12 @@ setdbit(register DBM *db, register long int dbit)
 	dirb = c / DBLKSIZ;
 
 	if (dirb != db->dirbno) {
-		(void) memset(db->dirbuf, 0, DBLKSIZ);
+		int got;
 		if (lseek(db->dirf, OFF_DIR(dirb), SEEK_SET) < 0
-		    || read(db->dirf, db->dirbuf, DBLKSIZ) < 0)
+		    || (got=read(db->dirf, db->dirbuf, DBLKSIZ)) < 0)
 			return 0;
+		if (got==0) 
+			memset(db->dirbuf,0,DBLKSIZ);
 		db->dirbno = dirb;
 
 		debug(("dir read: %d\n", dirb));
@@ -463,8 +468,13 @@ setdbit(register DBM *db, register long int dbit)
 
 	db->dirbuf[c % DBLKSIZ] |= (1 << dbit % BYTESIZ);
 
+#if 0
 	if (dbit >= db->maxbno)
 		db->maxbno += DBLKSIZ * BYTESIZ;
+#else
+	if (OFF_DIR((dirb+1))*BYTESIZ > db->maxbno) 
+		db->maxbno=OFF_DIR((dirb+1))*BYTESIZ;
+#endif
 
 	if (lseek(db->dirf, OFF_DIR(dirb), SEEK_SET) < 0
 	    || write(db->dirf, db->dirbuf, DBLKSIZ) < 0)