BUG #13764: function ghstore_consistent() returns a wrong value if var "strategy" contains an unsupported number - Mailing list pgsql-bugs

The following bug has been logged on the website:

Bug reference:      13764
Logged by:          Zhang Yan
Email address:      rucsoftsec@163.com
PostgreSQL version: 9.4.5
Operating system:   Linux Mint 15
Description:

function ghstore_consistent() computes the consistency and return a bool
value. It first computes the value of variable "strategy". It second
executes different branches of the code depending of different value of
variable "straregy". When the value of variable"strategy" is an unsupported
strategy number, function  ghstore_consistent() will executes the code in
line 584. It means function ghstore_consistent() fails, but the value of
variable "res" is "true" which will be returned in line 586. Therefore, does
it need to assign "false" to variable "res" after line 584?
the related code snippets in ghstore_consistent() are as following:
483 Datum
484 ghstore_consistent(PG_FUNCTION_ARGS)
485 {
486         GISTTYPE   *entry = (GISTTYPE *) DatumGetPointer(((GISTENTRY *)
PG_GETARG_POINTER(0))->key);
487         StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
488
489         /* Oid          subtype = PG_GETARG_OID(3); */
490         bool       *recheck = (bool *) PG_GETARG_POINTER(4);
491         bool            res = true;
492         BITVECP         sign;
493
494         /* All cases served by this function are inexact */
495         *recheck = true;
496
497         if (ISALLTRUE(entry))
498                 PG_RETURN_BOOL(true);
499
500         sign = GETSIGN(entry);
501
502         if (strategy == HStoreContainsStrategyNumber ||
503                 strategy == HStoreOldContainsStrategyNumber)
504         {
505                 HStore     *query = PG_GETARG_HS(1);
506                 HEntry     *qe = ARRPTR(query);
507                 char       *qv = STRPTR(query);
508                 int                     count = HS_COUNT(query);
509                 int                     i;
510
511                 for (i = 0; res && i < count; ++i)
512                 {
513                         int                     crc = crc32_sz((char *)
HS_KEY(qe, qv, i), HS_KEYLEN(qe, i));
514
515                         if (GETBIT(sign, HASHVAL(crc)))
516                         {
517                                 if (!HS_VALISNULL(qe, i))
518                                 {
519                                         crc = crc32_sz((char *)
HS_VAL(qe, qv, i), HS_VALLEN(qe, i));
520                                         if (!GETBIT(sign,
HASHVAL(crc)))
521                                                 res = false;
522                                 }
523                         }
524                         else
525                                 res = false;
526                 }
527         }
528         else if (strategy == HStoreExistsStrategyNumber)
529         {
530                 text       *query = PG_GETARG_TEXT_PP(1);
531                 int                     crc =
crc32_sz(VARDATA_ANY(query), VARSIZE_ANY_EXHDR(query));
532
533                 res = (GETBIT(sign, HASHVAL(crc))) ? true : false;
534         }
535         else if (strategy == HStoreExistsAllStrategyNumber)
536         {
537                 ArrayType  *query = PG_GETARG_ARRAYTYPE_P(1);
538                 Datum      *key_datums;
539                 bool       *key_nulls;
540                 int                     key_count;
541                 int                     i;
542
543                 deconstruct_array(query,
544                                                   TEXTOID, -1, false,
'i',
545                                                   &key_datums,
&key_nulls, &key_count);
546
547                 for (i = 0; res && i < key_count; ++i)
548                 {
549                         int                     crc;
550
551                         if (key_nulls[i])
552                                 continue;
553                         crc = crc32_sz(VARDATA(key_datums[i]),
VARSIZE(key_datums[i]) - VARHDRSZ);
554                         if (!(GETBIT(sign, HASHVAL(crc))))
555                                 res = FALSE;
556                 }
557         }
558         else if (strategy == HStoreExistsAnyStrategyNumber)
559         {
560                 ArrayType  *query = PG_GETARG_ARRAYTYPE_P(1);
561                 Datum      *key_datums;
562                 bool       *key_nulls;
563                 int                     key_count;
564                 int                     i;
565
566                 deconstruct_array(query,
567                                                   TEXTOID, -1, false,
'i',
568                                                   &key_datums,
&key_nulls, &key_count);
569
570                 res = FALSE;
571
572                 for (i = 0; !res && i < key_count; ++i)
573                 {
574                         int                     crc;
575
576                         if (key_nulls[i])
577                                 continue;
578                         crc = crc32_sz(VARDATA(key_datums[i]),
VARSIZE(key_datums[i]) - VARHDRSZ);
579                         if (GETBIT(sign, HASHVAL(crc)))
580                                 res = TRUE;
581                 }
582         }
583         else
584                 elog(ERROR, "Unsupported strategy number: %d",
strategy);
585
586         PG_RETURN_BOOL(res);
587 }