Add an ALWAYS() on an unreachable branch.

FossilOrigin-Name: a00928d48061c1169d5564996e19e7d7c2b962842100bb119846d0f696123c23

manifest

@@ -1,5 +1,5 @@
-C Fix\sthe\sLEFT\sJOIN\sstrength\sreduction\sfor\sIN\soperators\sin\sthe\sWHERE\sclause.\nFurther\ssimplifications\sand\srefinement\sof\sthe\salgorithm.
-D 2023-06-01T00:01:20.249
+C Add\san\sALWAYS()\son\san\sunreachable\sbranch.
+D 2023-06-01T00:28:11.164
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -587,7 +587,7 @@ F src/date.c cb71f73d5df5303ec6630971b9c8b8c7df466fa3233dbdc643d613806e53e554
 F src/dbpage.c f3eea5f7ec47e09ee7da40f42b25092ecbe961fc59566b8e5f705f34335b2387
 F src/dbstat.c ec92074baa61d883de58c945162d9e666c13cd7cf3a23bc38b4d1c4d0b2c2bef
 F src/delete.c 05e27e3a55dcfeadf2f7ca95a5c5e0928f182c04640ec1954ffa42f3d5c19341
-F src/expr.c 892a0645ed2085ced238ff19eaca6440b2ce78bd6d062fdbf1caa2a578faa690
+F src/expr.c 7bda4678e723ef53ec1abba5c843e289acf23be84056685ec63ce89565d672d2
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 03c134cc8bffe54835f742ddea0b72ebfc8f6b32773d175c71b8afeea6cb5c83
 F src/func.c 03e6b501f3056d0ba398bda17df938b2b566aa0b3ca7e1942a3cd1925d04ec36
@@ -2072,8 +2072,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 8396032ce14a75f408f0a75bcb36a6504d5188f20886e275746a2c336a74296f
-R 3b7dd10066b8cc3c88369c73d288e77c
+P 96c72dde79d4069f6c2f81467a35b617633f86f7a7dcafbda991affdaa1f8537
+R 40ac9a38209c3dcd8c11c72579ce41b0
 U drh
-Z 2eb94a55c7e32f21e9851a1c270b5eae
+Z 6c162dfd8f6d4fb3cc66b56b381f7dc7
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-96c72dde79d4069f6c2f81467a35b617633f86f7a7dcafbda991affdaa1f8537
+a00928d48061c1169d5564996e19e7d7c2b962842100bb119846d0f696123c23

src/expr.c

@@ -6071,7 +6071,7 @@ static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){
       ** both of which can be true.  But apart from these cases, if
       ** the left-hand side of the IN is NULL then the IN itself will be
       ** NULL. */
-      if( ExprUseXList(pExpr) && pExpr->x.pList->nExpr>0 ){
+      if( ExprUseXList(pExpr) && ALWAYS(pExpr->x.pList->nExpr>0) ){
         sqlite3WalkExpr(pWalker, pExpr->pLeft);
       }
       return WRC_Prune;