Jeremy Evans wrote:
> On Sat, Oct 15, 2011 at 11:46 PM, Yuriy Kaminskiy <[email protected]> wrote:
> 7> Whoops, patch eaten by hungry ewoks. Hopefully, inlining will work better:
>> Subject: fix false "ambiguous column" detection in multiple JOIN USING
>>
>> Instead of skipping only *next* table, we ignore matches when we have exactly
>> one match before and we joined to *previous* table with JOIN USING/NATURAL
>> JOIN.
>> So,
>> CREATE TABLE a(i, j);
>> CREATE TABLE b(j);
>> CREATE TABLE c(i);
>> CREATE TABLE d(j);
>> SELECT * FROM a JOIN b USING(j) JOIN c USING(i) JOIN d USING(j)
>> should work properly.
>>
>> The author or authors of this code dedicate any and all copyright interest
>> in this code to the public domain. We make this dedication for the benefit
>> of the public at large and to the detriment of our heirs and successors.
>> We intend this dedication to be an overt act of relinquishment in perpetuity
>> of all present and future rights to this code under copyright law.
>>
>> Signed-off-by: Yuriy M. Kaminskiy <[email protected]>
>>
>> Index: sqlite3-3.7.8/src/resolve.c
>> ===================================================================
>> --- sqlite3-3.7.8.orig/src/resolve.c 2011-10-16 09:18:20.000000000 +0400
>> +++ sqlite3-3.7.8/src/resolve.c 2011-10-16 09:39:53.000000000 +0400
>> @@ -190,33 +190,34 @@ static int lookupName(
>> for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
>> if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
>> IdList *pUsing;
>> - cnt++;
>> - pExpr->iTable = pItem->iCursor;
>> - pExpr->pTab = pTab;
>> - pMatch = pItem;
>> - pSchema = pTab->pSchema;
>> - /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY
>> */
>> - pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;
>> - if( i<pSrcList->nSrc-1 ){
>> - if( pItem[1].jointype & JT_NATURAL ){
>> + if( cnt == 1 ){
out of paranoia:
+ assert( i>0 );
+ assert( pItem->jointype!=0 );
(but both should be completely impossible)
>> + /* We already met this name once in some previous table(s),
>> + ** but... */
>> + if( pItem->jointype & JT_NATURAL ){
>> /* If this match occurred in the left table of a natural
>> join,
>> ** then skip the right table to avoid a duplicate match */
>> - pItem++;
>> - i++;
>> - }else if( (pUsing = pItem[1].pUsing)!=0 ){
>> + continue;
>> + }else if( (pUsing = pItem->pUsing)!=0 ){
>> /* If this match occurs on a column that is in the USING
>> clause
>> ** of a join, skip the search of the right table of the join
>> ** to avoid a duplicate match there. */
>> int k;
>> for(k=0; k<pUsing->nId; k++){
>> if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ){
>> - pItem++;
>> - i++;
>> break;
>> }
>> }
>> + if( k!=pUsing->nId )
>> + continue;
fwiw, I think both "continue;" can be replaced with "break;"
>> }
>> }
>> + cnt++;
>> + pExpr->iTable = pItem->iCursor;
>> + pExpr->pTab = pTab;
>> + pMatch = pItem;
>> + pSchema = pTab->pSchema;
>> + /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY
>> */
>> + pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;
>> break;
>> }
>> }
>
> I tried this patch and it does appear to fix the issue, but I'm also
> getting occasional segfaults in lookupName after applying it.
Thanks for testing.
Have no idea what can trigger sigsegv here.
Patch applied with any rejects/offsets/fuzziness?
`make test` shown no problem. `make fulltest` got some problems:
prepare.analyze3-1.1.8...
Expected: [999 999 499500]
Got: [2000 0 499500]
prepare.analyze3-1.1.9...
Expected: [999 999 499500]
Got: [2000 0 499500]
...
11 errors out of 2630788 tests
Failures on these tests: prepare.analyze3-1.1.8 prepare.analyze3-1.1.9
prepare.analyze3-1.2.8 prepare.analyze3-1.2.9 prepare.analyze3-1.3.8
prepare.analyze3-1.3.9 prepare.analyze3-2.4 prepare.analyze3-2.6
prepare.analyze3-2.7 prepare.analyze3-2.8 prepare.analyze3-2.9
... but they fails for me even with patch reverted.
And no segfaults.
Running few simple tests under valgrind have not produced anything suspicious.
> Haven't built a debug version of SQLite yet to determine exactly where.
I think SQL statement triggering segv would be enough.
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