Allow the OP_Column opcode to read rows that are larger than

SQLITE_LIMIT_LENGTH as long as the specific field being read out is
less than or equal to SQLITE_LIMIT_LENGTH.

FossilOrigin-Name: 1bf4848995ab094ad84ef4aa1563bce641d5acf7335fb4630c892b16cf7d7edd

manifest

@@ -1,5 +1,5 @@
-C Revise\sthe\sinitialization\sprocessing\sfor\sOP_Column\sto\smake\sit\sabout\n1.8\smillion\scycles\sfaster.
-D 2022-02-25T20:11:59.160
+C Allow\sthe\sOP_Column\sopcode\sto\sread\srows\sthat\sare\slarger\sthan\nSQLITE_LIMIT_LENGTH\sas\slong\sas\sthe\sspecific\sfield\sbeing\sread\sout\sis\nless\sthan\sor\sequal\sto\sSQLITE_LIMIT_LENGTH.
+D 2022-02-26T14:39:08.859
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -624,7 +624,7 @@ F src/upsert.c 8789047a8f0a601ea42fa0256d1ba3190c13746b6ba940fe2d25643a7e991937
 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0
 F src/util.c 602fe229f32a96ceccae4f40824129669582096f7c355f53dbac156c9fecef23
 F src/vacuum.c 6c38ddc52f0619865c91dae9c441d4d48bf3040d7dc1bc5b22da1e45547ed0b3
-F src/vdbe.c e3947ae70531c7e26fdca3da379bcb1aaad349dc1daad9841a11dd78f40e4705
+F src/vdbe.c 2dd9dc73c6e99db958550d1b66ea35046ff3d95ee2c752f41cf90a73ca742d25
 F src/vdbe.h a1d0e3b934e835e73edd146f2e7c4eadb711b5c9875c18159a57483fd78e550e
 F src/vdbeInt.h de2348c1643c1ac5bf0932452cbb708f52f52d8b4e29b667abdcfd4bacbf6aa6
 F src/vdbeapi.c 8863ffb5a7bac42fe9a68aaa3526ee29fc18fb02a9b27188b756de41e33856e9
@@ -1944,8 +1944,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 4e269902094e8f9d852e5fc852e473167048fdeb9034f1fb1436f6df205de926
-R 8636bb1bb599a232ab53a80eb27f1dd2
+P 3b7259ebd5b9b1f75577521c4d0d96f5503d302a513b20a0b17dbe8c3823dd33
+R a170b2aecc18c2441545989ed3dec05a
 U drh
-Z 2c3c6e68626da40fc12f58f70cf79dcd
+Z 8d66f3f471c1337d94ff51594a5973cc
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-3b7259ebd5b9b1f75577521c4d0d96f5503d302a513b20a0b17dbe8c3823dd33
+1bf4848995ab094ad84ef4aa1563bce641d5acf7335fb4630c892b16cf7d7edd

src/vdbe.c

@@ -2727,15 +2727,11 @@ op_column_restart:
       pC->aRow = sqlite3BtreePayloadFetch(pCrsr, &pC->szRow);
       assert( pC->szRow<=pC->payloadSize );
       assert( pC->szRow<=65536 );  /* Maximum page size is 64KiB */
-      if( pC->payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
-        goto too_big;
-      }
     }
     pC->cacheStatus = p->cacheCtr;
     pC->iHdrOffset = getVarint32(pC->aRow, aOffset[0]);
     pC->nHdrParsed = 0;
 
-
     if( pC->szRow<aOffset[0] ){      /*OPTIMIZATION-IF-FALSE*/
       /* pC->aRow does not have to hold the entire row, but it does at least
       ** need to cover the header of the record.  If pC->aRow does not contain
@@ -2888,6 +2884,7 @@ op_column_restart:
       pDest->n = len = (t-12)/2;
       pDest->enc = encoding;
       if( pDest->szMalloc < len+2 ){
+        if( len>db->aLimit[SQLITE_LIMIT_LENGTH] ) goto too_big;
         pDest->flags = MEM_Null;
         if( sqlite3VdbeMemGrow(pDest, len+2, 0) ) goto no_mem;
       }else{
@@ -2920,6 +2917,7 @@ op_column_restart:
       */
       sqlite3VdbeSerialGet((u8*)sqlite3CtypeMap, t, pDest);
     }else{
+      if( len>db->aLimit[SQLITE_LIMIT_LENGTH] ) goto too_big;
       rc = sqlite3VdbeMemFromBtree(pC->uc.pCursor, aOffset[p2], len, pDest);
       if( rc!=SQLITE_OK ) goto abort_due_to_error;
       sqlite3VdbeSerialGet((const u8*)pDest->z, t, pDest);