Patch that fixes dba_replace() file truncation issue

Adopted from: http://cvs.php.net/viewvc.cgi/php-src/ext/dba/libinifile/inifile.c?r1=1.14.2.1.2.5&r2=1.14.2.1.2.4&view=patch

--- libinifile/inifile.c	2007/12/31 07:20:05	1.14.2.1.2.4
+++ libinifile/inifile.c	2008/11/13 18:22:23	1.14.2.1.2.5
@@ -508,7 +508,9 @@
 	
 	/* 5 */
 	if (ret == SUCCESS) {
-		ret = inifile_truncate(dba, append ? pos_grp_next : pos_grp_start TSRMLS_CC); /* writes error on fail */
+		if (!value || (key->name && strlen(key->name))) {
+			ret = inifile_truncate(dba, append ? pos_grp_next : pos_grp_start TSRMLS_CC); /* writes error on fail */
+		}
 	}
 
 	if (ret == SUCCESS) {