From b1f3151bb75205d4ab34dbd7659bbfc80c79d175 Mon Sep 17 00:00:00 2001
From: drh <>
Date: Sun, 18 Oct 2026 22:48:50 +0000
Subject: [PATCH] If terms on the SELECT on the RHS of a vector IN are removed,
 then the subquery cannot be reused for other things, since it is now
 different. [bugs:/info/2026-10-16T22:07:15Z|Bug 2026-10-16T22:07:15Z]

FossilOrigin-Name: 080338a91b447c12186bbb4e23da1927ca448fee9a11cd6507f5f2041ee2dcba
---
 manifest            | 14 +++++++-------
 manifest.uuid       |  2 +-
 src/wherecode.c     |  3 +++
 test/rowvalue9.test | 25 +++++++++++++++++++++++++
 4 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/manifest b/manifest
index 3d6cd2996f..507f929596 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sharmless\scompiler\swarnings.
-D 2026-10-18T21:36:55.307
+C If\sterms\son\sthe\sSELECT\son\sthe\sRHS\sof\sa\svector\sIN\sare\sremoved,\sthen\sthe\nsubquery\scannot\sbe\sreused\sfor\sother\sthings,\ssince\sit\sis\snow\sdifferent.\n[bugs:/info/2026-10-16T22:07:15Z|Bug\s2026-10-16T22:07:15Z]
+D 2026-10-18T22:48:50.366
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -889,7 +889,7 @@ F src/wal.h c6251cfc1950643a976625ca452e46dc9b466b4f5dd2e85f244f29f79bf68ace
 F src/walker.c d5006d6b005e4ea7302ad390957a8d41ed83faa177e412f89bc5600a7462a014
 F src/where.c bb47341c327282bc91a6ec3abf9d335de8015ea2c2b57866df0c9c85db1936c6
 F src/whereInt.h 5d739acb94bf1fdf6edd502a919e3dcf2d340dda63cc1827304e119ea878f6f3
-F src/wherecode.c 69ff3d0fe8697d2ca482d25c15dfdc08cf8e4605ab5ab297e9d12b3dbc6812fd
+F src/wherecode.c f255e418ccf877f6bb9892145288728f1aa1a0ab8c2f2a57f82132e538c15b65
 F src/whereexpr.c 76f72a95c5cf0e8a8edb679ca4fb7afa17ba45ff4effe73c414266510109e701
 F src/window.c 79a17de595e62aa45961ef1cbe3392e7ebae69fdde3fd0b0200254bc4647025e
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
@@ -1650,7 +1650,7 @@ F test/rowvalue5.test 00740304ea6a53a8704640c7405690f0045d5d2a6b4b04dde7bccc14c3
 F test/rowvalue6.test d19b54feb604d5601f8614b15e214e0774c01087
 F test/rowvalue7.test 06ec0aca725bf683313d03793aa2943bc7f45a901848c7056a9665b769c8fc38
 F test/rowvalue8.test 5900eddad9e2c3c2e26f1a95f74aafc1232ee5e0
-F test/rowvalue9.test 7499a8fd7ca3a3f0e19d94e135355439aa2b596f86b775ca8de79672da2ca378
+F test/rowvalue9.test b23aec92a0fd76626cc2eac49a81a1fa3d95c57308e63abd462075eeb8cecaac
 F test/rowvalueA.test ada58d05065f6efe6a1349fcfedb16c199100409bf5085b418f4d71ba55f2be8
 F test/rowvaluefault.test 963ae9cdaed30a85a29668dd514e639f3556cae903ee9f172ea972d511c54fff
 F test/rowvaluevtab.test cd9747bb3f308086944c07968f547ad6b05022e698d80b9ffbdfe09ce0b8da6f
@@ -2292,8 +2292,8 @@ F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee
 F tool/warnings.sh a554d13f6e5cf3760f041b87939e3d616ec6961859c3245e8ef701d1eafc2ca2
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
 F tool/winmain.c 00c8fb88e365c9017db14c73d3c78af62194d9644feaf60e220ab0f411f3604c
-P 716b63c934156d8b19bda24c5bb544cc3d7d0ef66228150eea0a166d6e8c9caa
-R e198edc1938d0aca448ed22fd7c391a6
+P a68c9f3e98a7be2e7ac020fcbdf3b39cd9015e1d2fa07d30619c47a05cf7aab4
+R ce83b3ec6762628db0447a07d23376b1
 U drh
-Z e5d5b406b985d813a3dd3ebd117a7572
+Z 9dae443ecf14edfe9bec13186b54ea69
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index b0aa89e8b6..7d8c3be214 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-a68c9f3e98a7be2e7ac020fcbdf3b39cd9015e1d2fa07d30619c47a05cf7aab4
+080338a91b447c12186bbb4e23da1927ca448fee9a11cd6507f5f2041ee2dcba
diff --git a/src/wherecode.c b/src/wherecode.c
index 0ee1d90bb9..cf9b62e629 100644
--- a/src/wherecode.c
+++ b/src/wherecode.c
@@ -618,6 +618,9 @@ static Expr *removeUnindexableInClauseTerms(
           nRhs++;
         }
       }
+      if( nRhs<pOrigRhs->nExpr ){
+        ExprClearProperty(pNew, EP_Subrtn); /* See bug 2026-10-16T22:07:15Z */
+      }
       sqlite3ExprListDelete(db, pOrigRhs);
       if( pOrigLhs ){
         sqlite3ExprListDelete(db, pOrigLhs);
diff --git a/test/rowvalue9.test b/test/rowvalue9.test
index baa13f4f94..d31808c3c4 100644
--- a/test/rowvalue9.test
+++ b/test/rowvalue9.test
@@ -348,5 +348,30 @@ do_eqp_test 9.5e {
   *SEARCH t1 USING COVERING INDEX i2*
 }
 
+# Bug 2026-10-16T22:07:15Z
+#
+# Problem bisects to check-in 18a99d9cfbc3a041 (2023-02-13 18:37:48.912).
+# Prior to fix, tests 10.1 and 10.2 would fail.
+#
+reset_db
+do_execsql_test 10.0 {
+  CREATE TABLE t1(a INT PRIMARY KEY, b INT);
+  INSERT INTO t1 VALUES(1,1);
+  CREATE TABLE t2(c INT PRIMARY KEY, d INT);
+  INSERT INTO t2 VALUES(1,1);
+  ANALYZE;
+}
+do_execsql_test 10.1 {
+  SELECT count(*) FROM t1, t2 WHERE a=c AND (a,b) IN ((1,1), (1,2), (1,3));
+} 1
+do_execsql_test 10.2 {
+  SELECT t1.*     FROM t1, t2 WHERE a=c AND (a,b) IN ((1,1), (1,2), (1,3));
+} {1 1}
+do_execsql_test 10.3 {
+  SELECT t2.*     FROM t1, t2 WHERE a=c AND (a,b) IN ((1,1), (1,2), (1,3));
+} {1 1}
+do_execsql_test 10.4 {
+  SELECT *        FROM t1, t2 WHERE a=c AND (a,b) IN ((1,1), (1,2), (1,3));
+} {1 1 1 1}
 
 finish_test