From: drh <>
Date: Sat, 14 May 2022 19:05:13 +0000 (+0000)
Subject: Do not allow an index scan on an index-on-expression for a RIGHT JOIN because
X-Git-Tag: version-3.39.0~138
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=96d5549778c369e723157498e26496144a1caeae;p=thirdparty%2Fsqlite.git

Do not allow an index scan on an index-on-expression for a RIGHT JOIN because
the index might not be positioned on the correct row when running the
the right-join no-match loop.
dbsqlfuzz 39ee60004ff027a9e2846cf76e02cd5ac0953739

FossilOrigin-Name: 2277f9ba7087dd993ac0f4007c523aa9cf74dba187f53af03d8c164886726fee
---

diff --git a/manifest b/manifest
index cda1c3f8ca..85cf3a7bf2 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Improved\sdebugging\scomment\sgeneration\sfor\sthe\sOP_Column\sopcode.
-D 2022-05-14T17:40:47.718
+C Do\snot\sallow\san\sindex\sscan\son\san\sindex-on-expression\sfor\sa\sRIGHT\sJOIN\sbecause\nthe\sindex\smight\snot\sbe\spositioned\son\sthe\scorrect\srow\swhen\srunning\sthe\nthe\sright-join\sno-match\sloop.\ndbsqlfuzz\s39ee60004ff027a9e2846cf76e02cd5ac0953739
+D 2022-05-14T19:05:13.161
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -640,7 +640,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c b9df133a705093da8977da5eb202eaadb844839f1c7297c08d33471f5491843d
 F src/wal.h c3aa7825bfa2fe0d85bef2db94655f99870a285778baa36307c0a16da32b226a
 F src/walker.c f890a3298418d7cba3b69b8803594fdc484ea241206a8dfa99db6dd36f8cbb3b
-F src/where.c d4d543f06b09ff8bac05072b015a2181f9c48561b1a146158aaaf09e40817567
+F src/where.c 2ee27fed4a5564cddfc6710a539037d18e39e75cdf90b3f48d476c3b9767592e
 F src/whereInt.h 8da918f392bf202ccc0ee61291455b33ad171d209445f1ff3eaf62e0b6f6b363
 F src/wherecode.c 2a8a73bcf1886632f2b2247c79395f94852a4b74484d8aa70a005892ce73d339
 F src/whereexpr.c efed370c684dce04eab949202c5452bbde993efb198de43c7a88f59411ad2a2c
@@ -1148,7 +1148,7 @@ F test/join4.test 1a352e4e267114444c29266ce79e941af5885916
 F test/join5.test d22b6cba8fb59ab3f1c82701434c360705eb12d4ce200c449f37b018fc47681a
 F test/join6.test f809c025fa253f9e150c0e9afd4cef8813257bceeb6f46e04041228c9403cc2c
 F test/join7.test 8e72de4b45e5e930d18c305c7efe86015fb2552731e4e03ea226353036b0dab0
-F test/join8.test 0558cbab9ae545801278e824cd65f64a98309050f8c66182e1cfe7a892fd3add
+F test/join8.test adf30584c6d0cc61816b24fd6f3cc8386ce89f579da4b65a6c8e05c2f2dce08e
 F test/join9.test 9056ddd3b0c0f4f9d658f4521038d9a37dc23ead8ca9a505d0b0db2b6a471e05
 F test/joinA.test 7eab225dc1c1ab258a5e62513a4ed7cabbd3db971d59d5d92f4fb6fa14c12f6a
 F test/joinB.test 1b2ba3fc8568b49411787fccbf540570c148e9b6a53a30f80691cb6268098ded
@@ -1954,8 +1954,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 9d17233c7d98bf25c1a518d067e778708b3db6d6302edd8d7e376ba0ba4f1c30
-R 3e11d035d04bb8add88257d626a130df
+P 3e073bfddfcd652dfae8656d8978a4de427d21847fdaccfce53b6b895ad33f01
+R 45a6d14271adb894f8a23a1d1403bcc8
 U drh
-Z 4f25ce32e3f912e3438ae5561148601c
+Z e0ba2eaedaa5d31f63ce00b4accf03e3
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index f030da8c3d..42b2c148f1 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-3e073bfddfcd652dfae8656d8978a4de427d21847fdaccfce53b6b895ad33f01
\ No newline at end of file
+2277f9ba7087dd993ac0f4007c523aa9cf74dba187f53af03d8c164886726fee
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index 8cbf9da89b..b0b1e37074 100644
--- a/src/where.c
+++ b/src/where.c
@@ -3482,7 +3482,14 @@ static int whereLoopAddBtree(
         }
         ApplyCostMultiplier(pNew->rRun, pTab->costMult);
         whereLoopOutputAdjust(pWC, pNew, rSize);
-        rc = whereLoopInsert(pBuilder, pNew);
+        if( (pSrc->fg.jointype & JT_RIGHT)!=0 && pProbe->aColExpr ){
+          /* Do not do an SCAN of a index-on-expression in a RIGHT JOIN
+          ** because the cursor used to access the index might not be
+          ** positioned to the correct row during the right-join no-match
+          ** loop. */
+        }else{
+          rc = whereLoopInsert(pBuilder, pNew);
+        }
         pNew->nOut = rSize;
         if( rc ) break;
       }
@@ -6168,6 +6175,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
   }
 
   assert( pWInfo->nLevel<=pTabList->nSrc );
+  if( pWInfo->pExprMods ) whereUndoExprMods(pWInfo);
   for(i=0, pLevel=pWInfo->a; i<pWInfo->nLevel; i++, pLevel++){
     int k, last;
     VdbeOp *pOp, *pLastOp;
@@ -6304,7 +6312,6 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
 
   /* Final cleanup
   */
-  if( pWInfo->pExprMods ) whereUndoExprMods(pWInfo);
   pParse->nQueryLoop = pWInfo->savedNQueryLoop;
   whereInfoFree(db, pWInfo);
   return;
diff --git a/test/join8.test b/test/join8.test
index ffa1a60f52..6dee54b0ae 100644
--- a/test/join8.test
+++ b/test/join8.test
@@ -341,4 +341,38 @@ do_execsql_test join8-10080 {
     FROM t2 NATURAL JOIN t1 RIGHT JOIN t3 ON t1.c0<>0;
 } {- 3}
 
+# 2022-05-14
+# index-on-expr scan on a RIGHT JOIN
+# dbsqlfuzz 39ee60004ff027a9e2846cf76e02cd5ac0953739
+#
+reset_db
+db null -
+do_execsql_test join8-11000 {
+  CREATE TABLE t1(a);
+  CREATE TABLE t2(b);
+  INSERT INTO t2 VALUES(0),(1),(2);
+  SELECT * FROM t1 RIGHT JOIN t2 ON (a=b) WHERE 99+(b+1)!=99;
+} {- 0 - 1 - 2}
+do_execsql_test join8-11010 {
+  CREATE INDEX t2b ON t2(b+1) WHERE b IS NOT NULL;
+  SELECT * FROM t1 RIGHT JOIN t2 ON (a=b) WHERE 99+(b+1)!=99;
+} {- 0 - 1 - 2}
+do_execsql_test join8-11020 {
+  DROP TABLE t1;
+  DROP TABLE t2;
+  CREATE TABLE t1(a);
+  CREATE TABLE t2(b, c, d);
+  INSERT INTO t2 VALUES(1, 3, 'not-4');
+  SELECT b, d FROM t1 RIGHT JOIN t2 WHERE (b+0)=1 AND d!=4;
+} {1 not-4}
+do_execsql_test join8-11030 {
+  CREATE INDEX i2 ON t2((b+0), d);
+  SELECT b, d FROM t1 RIGHT JOIN t2 WHERE (b+0)=1 AND d!=4;
+} {1 not-4}
+do_execsql_test join8-11040 {
+  DROP INDEX i2;
+  CREATE INDEX i2 ON t2((b+0), d) WHERE d IS NOT NULL;
+  SELECT b, d FROM t1 RIGHT JOIN t2 WHERE (b+0)=1 AND d!=4;
+} {1 not-4}
+
 finish_test