ITS#2865 don't try to calloc 0 bytes, log an error and return instead.

Don't crash in slapcat when NULL entry is returned.

servers/slapd/entry.c

@@ -659,6 +659,16 @@ int entry_decode(struct berval *bv, Entry **e)
 	BerVarray bptr;
 
 	i = entry_getlen(&ptr);
+	if (!i) {
+#ifdef NEW_LOGGING
+		LDAP_LOG( OPERATION, INFO, 
+			"entry_decode: entry length was zero\n", 0, 0, 0);
+#else
+		Debug( LDAP_DEBUG_ANY,
+			"entry_decode: entry length was zero\n", 0, 0, 0);
+#endif
+		return LDAP_OTHER;
+	}
 	x = ch_calloc(1, i);
 	i = entry_getlen(&ptr);
 	x->e_name.bv_val = (char *) ptr;

servers/slapd/tools/slapcat.c

@@ -66,6 +66,13 @@ main( int argc, char **argv )
 		Entry* e = be->be_entry_get( be, id );
 		op.o_bd = be;
 
+		if ( e == NULL ) {
+			printf("# no data for entry id=%08lx\n\n", (long) id );
+			rc = EXIT_FAILURE;
+			if( continuemode ) continue;
+			break;
+		}
+
 		if( sub_ndn.bv_len && !dnIsSuffix( &e->e_nname, &sub_ndn ) ) {
 			be_entry_release_r( &op, e );
 			continue;
@@ -89,13 +96,6 @@ main( int argc, char **argv )
 			printf( "# id=%08lx\n", (long) id );
 		}
 
-		if ( e == NULL ) {
-			printf("# no data for entry id=%08lx\n\n", (long) id );
-			rc = EXIT_FAILURE;
-			if( continuemode ) continue;
-			break;
-		}
-
 		data = entry2str( e, &len );
 		be_entry_release_r( &op, e );