Do not convert an expression node that is already TK_REGISTER into a

new TK_REGISTER.  This is a follow-up to [663f5dd32d9db832] that fixes a
bug discovered by dbsqlfuzz.

FossilOrigin-Name: fcb669cfaa8a59ca710504d5aaa1936f65a6da8ff13473ad84458f97a6fd1f49

manifest

@@ -1,5 +1,5 @@
-C Fix\san\sincorrect\stcl\scomment\sthat\sappeared\sin\smany\sfts5\stest\sfiles.
-D 2024-06-24T18:06:15.031
+C Do\snot\sconvert\san\sexpression\snode\sthat\sis\salready\sTK_REGISTER\sinto\sa\nnew\sTK_REGISTER.\s\sThis\sis\sa\sfollow-up\sto\s[663f5dd32d9db832]\sthat\sfixes\sa\nbug\sdiscovered\sby\sdbsqlfuzz.
+D 2024-06-28T17:14:00.360
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -755,7 +755,7 @@ F src/printf.c 8b250972305e14b365561be5117ed0fd364e4fd58968776df1ce64c6280b90f9
 F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c
 F src/resolve.c 7e8d23ce7cdbfedf351a47e759f2722e8182ca10fd7580be43f4ce1f1a228145
 F src/rowset.c 8432130e6c344b3401a8874c3cb49fefe6873fec593294de077afea2dce5ec97
-F src/select.c d26ac0a13b4154cbd71a9a57ca024350cd73f0f6fcf0ca0cbb4537e2d5b3e257
+F src/select.c a1c8fadd45d0843b14793db2af49809a5327db5cca9d87d507b57aa748ee6ee2
 F src/shell.c.in 2ccbed6a9fd451399b0f378aafa323ad2286fa9de54ae0cd28f32907cd94d18d
 F src/sqlite.h.in 6c884a87bbf8828562b49272025a1e66e3801a196a58b0bdec87edcd2c9c8fc1
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
@@ -1074,7 +1074,7 @@ F test/descidx2.test a0ba347037ff3b811f4c6ceca5fd0f9d5d72e74e59f2d9de346a9d2f6ad
 F test/descidx3.test 953c831df7ea219c73826dfbf2f6ee02d95040725aa88ccb4fa43d1a1999b926
 F test/diskfull.test 106391384780753ea6896b7b4f005d10e9866b6e
 F test/distinct.test 691c9e850b0d0b56b66e7e235453198cb4cf0760e324b7403d3c5abbeab0a014
-F test/distinct2.test 931a242fccaa05f17232e23acc9b2debe42901d90db723ddca038f7758951b5f
+F test/distinct2.test 4d6316b6487a0aa5a90bee111575c957e2a5ba5a9be9156febe9533ce78876e8
 F test/distinctagg.test 40d7169ae5846caaf62c6e307d2ca3c333daf9b6f7cde888956a339a97afe85f
 F test/e_blobbytes.test 4c01dfe4f12087b92b20705a3fdfded45dc4ed16d5a211fed4e1d2786ba68a52
 F test/e_blobclose.test 692fc02a058476c2222a63d97e3f3b2b809c1842e5525ded7f854d540ac2e075
@@ -2195,8 +2195,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 56d265f956fe6433b625c6d732e55f387af3f643e705316f5a6f709d63731669
-R 5ad9950c3d8fa87fe57068f06313a6c9
-U dan
-Z 3992b6a75558611778f9237da672a1e0
+P d07085e2035b52a7edd27980523225e59c5bf851fb4a6de975f03e653b937c9c
+R 6b4e371b1a6983b6d20bf6bb77f15e3d
+U drh
+Z 1da9b70811e2736c2416513d2f56f791
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-d07085e2035b52a7edd27980523225e59c5bf851fb4a6de975f03e653b937c9c
+fcb669cfaa8a59ca710504d5aaa1936f65a6da8ff13473ad84458f97a6fd1f49

src/select.c

@@ -8336,7 +8336,10 @@ int sqlite3Select(
         if( iOrderByCol ){
           Expr *pX = p->pEList->a[iOrderByCol-1].pExpr;
           Expr *pBase = sqlite3ExprSkipCollateAndLikely(pX);
-          if( ALWAYS(pBase!=0) && pBase->op!=TK_AGG_COLUMN ){
+          if( ALWAYS(pBase!=0)
+           && pBase->op!=TK_AGG_COLUMN
+           && pBase->op!=TK_REGISTER
+          ){
             sqlite3ExprToRegister(pX, iAMem+j);
           }
         }

test/distinct2.test

@@ -362,4 +362,22 @@ do_execsql_test 5070 {
   SELECT v4.e FROM t3 LEFT JOIN v4 ON true GROUP BY 1;
 } NULL
 
+# 2024-06-28 dbsqlfuzz 46343912848a603e32c6072cae792eb056bac897
+# Do not call sqlite3ExprToRegister() on an expression that is already
+# a register.
+#
+do_execsql_test 5080 {
+  CREATE TABLE dual(dummy TEXT);
+  INSERT INTO dual VALUES('X');
+  SELECT 11 = (
+                SELECT b
+                  FROM (
+                         SELECT a AS b
+                           FROM dual
+                           LEFT JOIN (SELECT 22 AS a FROM dual)
+                       )
+                 GROUP BY b, b
+              );
+} 0
+
 finish_test