database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-11-16 23:02:26 +03:00
Code Activity

Fix a problem causing an infinite loop or other malfunction in some UPDATE

Browse Source 
statements with an OR term in the WHERE clause.

FossilOrigin-Name: feb2c2b6f66b0f45490beb1642d99cdb89fa220e299a8c118929df557c814189
This commit is contained in:
dan
2018-01-16 13:37:43 +00:00
parent ded2d99d73
commit 0c2ba13e02
4 changed files with 45 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
src/where.c
View File

@@ -4801,15 +4801,32 @@ WhereInfo *sqlite3WhereBegin(
/* If the caller is an UPDATE or DELETE statement that is requesting
** to use a one-pass algorithm, determine if this is appropriate.
**
** A one-pass approach can be used if the caller has requested one
** and either (a) the scan visits at most one row or (b) each
** of the following are true:
**
** * the caller has indicated that a one-pass approach can be used
** with multiple rows (by setting WHERE_ONEPASS_MULTIROW), and
** * the table is not a virtual table, and
** * either the scan does not use the OR optimization or the caller
** is a DELETE operation (WHERE_DUPLICATES_OK is only specified
** for DELETE).
**
** The last qualification is because an UPDATE statement uses
** WhereInfo.aiCurOnePass[1] to determine whether or not it really can
** use a one-pass approach, and this is not set accurately for scans
** that use the OR optimization.
*/
assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 ){
int wsFlags = pWInfo->a[0].pWLoop->wsFlags;
int bOnerow = (wsFlags & WHERE_ONEROW)!=0;
if( bOnerow
|| ((wctrlFlags & WHERE_ONEPASS_MULTIROW)!=0
&& 0==(wsFlags & WHERE_VIRTUALTABLE))
){
if( bOnerow || (
0!=(wctrlFlags & WHERE_ONEPASS_MULTIROW)
&& 0==(wsFlags & WHERE_VIRTUALTABLE)
&& (0==(wsFlags & WHERE_MULTI_OR) || (wctrlFlags & WHERE_DUPLICATES_OK))
)){
pWInfo->eOnePass = bOnerow ? ONEPASS_SINGLE : ONEPASS_MULTI;
if( HasRowid(pTabList->a[0].pTab) && (wsFlags & WHERE_IDX_ONLY) ){
if( wctrlFlags & WHERE_ONEPASS_MULTIROW ){