Do not apply the [/info/e33da6d5dc964db8|EXISTS-to-JOIN optimization] if

the subquery contains a LIMIT clause.
[forum:/forumpost/2025-07-23T10:59:14z|forum post 2025-07-23T10:59:14z].

FossilOrigin-Name: 314c493f273a34dff7b9f954e7553bc540bbcf5b913f779ef9ce0b9ba11acf7a

manifest

@@ -1,5 +1,5 @@
-C Fix\sa\spotentially\suninitialized\sfield\sin\sthe\sWhereLoop\sobject\sthat\sis\sused\nas\spart\sof\sthe\sskip-ahead-distinct\soptimization.\s\sThis\sfixes\svarious\n[forum:/timeline?ymd=20250722&u=yxchen&vfx|recent\sforum\sreports\sfrom\syxchen].
-D 2025-07-22T15:51:41.542
+C Do\snot\sapply\sthe\s[/info/e33da6d5dc964db8|EXISTS-to-JOIN\soptimization]\sif\nthe\ssubquery\scontains\sa\sLIMIT\sclause.\n[forum:/forumpost/2025-07-23T10:59:14z|forum\spost\s2025-07-23T10:59:14z].
+D 2025-07-23T12:48:16.339
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -786,7 +786,7 @@ F src/printf.c 71b6d3a0093bf23f473e25480ca0024e8962681506c75f4ffd3d343a3f0ab113
 F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c
 F src/resolve.c e344c0ff75db05acd80a81ab090547d28d0e990f6f411a428d429183a7c73927
 F src/rowset.c 8432130e6c344b3401a8874c3cb49fefe6873fec593294de077afea2dce5ec97
-F src/select.c 40bf8b15afca243a7222ab6301f1a283cc862c59aead7d22fc569e1843430fd3
+F src/select.c a6be657216e1fb72f85dad7df0dba0eb79fe76527c08caa65da8fe44f0e4db44
 F src/shell.c.in 7918c9355667b3b348e5850f0dad9095476ef942ee3b96ee9b8bc2710adda1da
 F src/sqlite.h.in 5c54f2461a1ea529bab8499148a2b238e2d4bb571d59e8ea5322d0c190abb693
 F src/sqlite3.rc 015537e6ac1eec6c7050e17b616c2ffe6f70fca241835a84a4f0d5937383c479
@@ -1141,7 +1141,7 @@ F test/exclusive.test 7ff63be7503990921838d5c9f77f6e33e68e48ed1a9d48cd28745bf650
 F test/exclusive2.test cd70b1d9c6fffd336f9795b711dcc5d9ceba133ad3f7001da3fda63615bdc91e
 F test/exec.test e949714dc127eaa5ecc7d723efec1ec27118fdd7
 F test/exists.test 79a75323c78f02bbe9c251ea502a092f9ef63dac
-F test/existsexpr.test 40ddd9500109579dd949cd15bbb4e3a88f79f905d1f31905b9493651f60aacf6
+F test/existsexpr.test 9c4b77c4729281cc2ae63b9b460d0598ce28cc7876135e3e2c21629bbc8d077a
 F test/existsexpr2.test dc23e76389eff3d29f6488ff733012a3560cd67ec8cfaecbecd52cced5d5af11
 F test/existsfault.test ff41c11f3052c1bbd4f8dd557802310026253d67d7c4e3a180c16d2f0862973e
 F test/expr.test 4ada8eb822c45ef27a36851a258004d43c1e95e7c82585a1217e732084e4482c
@@ -2213,8 +2213,8 @@ F tool/version-info.c 3b36468a90faf1bbd59c65fd0eb66522d9f941eedd364fabccd7227350
 F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee87c1b31a7
 F tool/warnings.sh 1ad0169b022b280bcaaf94a7fa231591be96b514230ab5c98fbf15cd7df842dd
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 477211be60cd873d078293f0dd767506c069c3dd83bc1759ae7258d4d3dff359
-R f8ba680ce9b1657fae69f61ff9d57d1d
+P c10f9970c6a3ffacaef0f0728fc7ff11011686835dc78ca43035c0493e0af319
+R 2a1458b5adcdacd64c8e9eb75b91b34a
 U drh
-Z c9346dfa43d7f5c186a9a25b6a8a2164
+Z 924a5281dd1a8b6cec0c51ca10e1c48a
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-c10f9970c6a3ffacaef0f0728fc7ff11011686835dc78ca43035c0493e0af319
+314c493f273a34dff7b9f954e7553bc540bbcf5b913f779ef9ce0b9ba11acf7a

src/select.c

@@ -7462,6 +7462,7 @@ static SQLITE_NOINLINE void existsToJoin(
       if( pSub->pSrc->nSrc==1
        && (pSub->selFlags & SF_Aggregate)==0
        && !pSub->pSrc->a[0].fg.isSubquery
+       && pSub->pLimit==0
       ){
         memset(pWhere, 0, sizeof(*pWhere));
         pWhere->op = TK_INTEGER;

test/existsexpr.test

@@ -421,6 +421,12 @@ do_execsql_test 7.0 {
   2 {}
 }
 
-
+# https://sqlite.org/forum/forumpost/2025-07-23T10:59:14z
+reset_db
+do_execsql_test 8.0 {
+  CREATE TABLE t0 (c0 INT);  INSERT INTO t0(c0) VALUES (1);
+  CREATE TABLE t1(c0 INT);   INSERT INTO t1(c0) VALUES (2);
+  SELECT * FROM t1 WHERE EXISTS (SELECT 1 FROM t0 LIMIT 0);
+} {}
 
 finish_test