Check-in [a9657c87c53c1922] is wrong: the IndexedExpr.bMaybeNullRow flag is

required for virtual columns if they are part of an outer join.  Add a
test case (derived from dbsqlfuzz b9e65e2f110df998f1306571fae7af6c01e4d92b)
to prove it.

FossilOrigin-Name: 4484ec6d26b31305e31de89bdbae26344d8083a7e7de20861430d31737d9979c

manifest

@@ -1,5 +1,5 @@
-C When\scompiling\swith\sSQLITE_ALLOW_ROWID_IN_VIEW,\sif\sthe\sRETURNING\sclause\sof\nan\sUPDATE\sof\sa\sview\sspecifies\sa\srowid,\sthen\sreturn\sNULL\sfor\sthe\svalue\sof\nthat\srowid.\s\sdbsqlfuzz\s7863696e9e5ec10b29bcf5ab2681cd6c82a78a4a.
-D 2024-04-05T11:23:51.958
+C Check-in\s[a9657c87c53c1922]\sis\swrong:\sthe\sIndexedExpr.bMaybeNullRow\sflag\sis\nrequired\sfor\svirtual\scolumns\sif\sthey\sare\spart\sof\san\souter\sjoin.\s\sAdd\sa\ntest\scase\s(derived\sfrom\sdbsqlfuzz\sb9e65e2f110df998f1306571fae7af6c01e4d92b)\nto\sprove\sit.
+D 2024-04-05T13:56:05.021
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -835,7 +835,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 887fc4ca3f020ebb2e376f222069570834ac63bf50111ef0cbf3ae417048ed89
 F src/wal.h ba252daaa94f889f4b2c17c027e823d9be47ce39da1d3799886bbd51f0490452
 F src/walker.c 7c7ea0115345851c3da4e04e2e239a29983b61fb5b038b94eede6aba462640e2
-F src/where.c 08ffccb5b8df523a484af2ae8593c8f571113475fe76b13360f2dfd74e117b4e
+F src/where.c 9982128f010a699560fb5be37633801c7641ac3540f49db43cec878025929a0e
 F src/whereInt.h 82a13766f13d1a53b05387c2e60726289ef26404bc7b9b1f7770204d97357fb8
 F src/wherecode.c 5d77db30a2a3dd532492ae882de114edba2fae672622056b1c7fd61f5917a8f1
 F src/whereexpr.c 7b64295f1d82ad0928df435925dd7bbd5997b44a026153113eace0d9e71ff435
@@ -1338,7 +1338,7 @@ F test/joinC.test 1f1a602c2127f55f136e2cbd3bf2d26546614bf8cffe5902ec1ac9c07f87f2
 F test/joinD.test 2ce62e7353a0702ca5e70008faf319c1d4686aa19fba34275c6d1da0e960be28
 F test/joinE.test d5d182f3812771e2c0d97c9dcf5dbe4c41c8e21c82560e59358731c4a3981d6b
 F test/joinF.test 53dd66158806823ea680dd7543b5406af151b5aafa5cd06a7f3231cd94938127
-F test/joinH.test d5054173442fdf98260eeb6bb9751daa733b0ae6842fe50dcbd5469945b86985
+F test/joinH.test 55f69e64da74d4eca2235237f3acb657aef181e22e45daa228e35bba865e0255
 F test/journal1.test c7b768041b7f494471531e17abc2f4f5ebf9e5096984f43ed17c4eb80ba34497
 F test/journal2.test 9dac6b4ba0ca79c3b21446bbae993a462c2397c4
 F test/journal3.test 7c3cf23ffc77db06601c1fcfc9743de8441cb77db9d1aa931863d94f5ffa140e
@@ -2184,8 +2184,9 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 8b41ef8690001eb299f5b7182c28f5318333bff5b505e1d59d6e6f4556b1c759
-R f56441a29ebaf6b9cc2fa5b75235bdce
+P c7896e88850669e18e89d44c4169d4f4a5d4b904bea6ccb2ac64f93b6d348a42
+Q -a9657c87c53c19228a42559c82c54b504a5ad729e407e9e2c7dabcc0c949b261
+R 00fdd25fa9a3c1e58bfe6d44fd3eb812
 U drh
-Z ca20487feeb5219923a08470db600847
+Z d45c3b35e63ad3a95f4d8ac3c99323f3
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-c7896e88850669e18e89d44c4169d4f4a5d4b904bea6ccb2ac64f93b6d348a42
+4484ec6d26b31305e31de89bdbae26344d8083a7e7de20861430d31737d9979c

src/where.c

@@ -5948,16 +5948,10 @@ static SQLITE_NOINLINE void whereAddIndexedExpr(
   for(i=0; i<pIdx->nColumn; i++){
     Expr *pExpr;
     int j = pIdx->aiColumn[i];
-    int bMaybeNullRow;
     if( j==XN_EXPR ){
       pExpr = pIdx->aColExpr->a[i].pExpr;
-      testcase( pTabItem->fg.jointype & JT_LEFT );
-      testcase( pTabItem->fg.jointype & JT_RIGHT );
-      testcase( pTabItem->fg.jointype & JT_LTORJ );
-      bMaybeNullRow = (pTabItem->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))!=0;
     }else if( j>=0 && (pTab->aCol[j].colFlags & COLFLAG_VIRTUAL)!=0 ){
       pExpr = sqlite3ColumnExpr(pTab, &pTab->aCol[j]);
-      bMaybeNullRow = 0;
     }else{
       continue;
     }
@@ -5989,7 +5983,7 @@ static SQLITE_NOINLINE void whereAddIndexedExpr(
     p->iDataCur = pTabItem->iCursor;
     p->iIdxCur = iIdxCur;
     p->iIdxCol = i;
-    p->bMaybeNullRow = bMaybeNullRow;
+    p->bMaybeNullRow = (pTabItem->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))!=0;
     if( sqlite3IndexAffinityStr(pParse->db, pIdx) ){
       p->aff = pIdx->zColAff[i];
     }

test/joinH.test

@@ -309,4 +309,36 @@ do_execsql_test 12.3 {
   SELECT * FROM t1 LEFT JOIN t2 ON true RIGHT JOIN t3 ON d2=e3 WHERE c2 BETWEEN NULL AND a1;
 }
 
+#-------------------------------------------------------------------------
+# 2024-04-05 dbsqlfuzz b9e65e2f110df998f1306571fae7af6c01e4d92b
+reset_db
+do_execsql_test 13.1 {
+  CREATE TABLE t1(a INT AS (b), b INT);
+  INSERT INTO t1(b) VALUES(123);
+  CREATE TABLE t2(a INT, c INT);
+  SELECT a FROM t2 NATURAL RIGHT JOIN t1;
+} {123}
+do_execsql_test 13.2 {
+  CREATE INDEX t1a ON t1(a);
+  SELECT a FROM t2 NATURAL RIGHT JOIN t1;
+} {123}
+# Further tests of the same logic (indexes on expressions
+# used by RIGHT JOIN) from check-in ffe23af73fcb324d and
+# forum post https://sqlite.org/forum/forumpost/9b491e1debf0b67a.
+db null NULL
+do_execsql_test 13.3 {
+  CREATE TABLE t3(a INT, b INT);
+  CREATE UNIQUE INDEX t3x ON t3(a, a+b);
+  INSERT INTO t3(a,b) VALUES(1,2),(4,8),(16,32),(4,80),(1,-300);
+  CREATE TABLE t4(x INT, y INT);
+  INSERT INTO t4(x,y) SELECT a, b FROM t3;
+  INSERT INTO t4(x,y) VALUES(99,99);
+  SELECT a1.a, sum( a1.a+a1.b ) FROM t3 AS a1 RIGHT JOIN t4 ON a=x
+   GROUP BY a1.a ORDER BY 1;
+} {NULL NULL 1 -592 4 192 16 48}
+do_execsql_test 13.4 {
+  SELECT sum( a1.a+a1.b ) FROM t3 AS a1 RIGHT JOIN t3 ON true
+   GROUP BY a1.a ORDER BY 1;
+} {-1480 240 480}
+
 finish_test