Merge enhancements from trunk.

FossilOrigin-Name: d1731385c077f298b0cf654d6183ed40f7e5c07e4e2ab7f69109cf951ce99d9e

diff --cc manifest
index 262df6de9d55fb137b0558410c5a1094a8b4e3fd,abeefcdd04682bfbd5a62a789cb0457a9d9d8890..6ecfce648f2dc74e794876c9acfec3e12cce1469
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Add\sthe\stables_used()\stable-valued\sfunction\sas\sa\svariation\son\sbytecode().
- D 2020-03-26T16:48:18.810
 -C Use\s__atomic_load_n()\sand\s__atomic_store_n()\sfor\sa\sfew\smore\sthings\swhere\sthey\sare\savailable.
 -D 2020-03-30T13:35:05.649
++C Merge\senhancements\sfrom\strunk.
++D 2020-04-02T12:24:08.483
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
  F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@@ -478,8 -478,8 +478,8 @@@ F src/btreeInt.h dee1a1d0c621524e006bb2
  F src/build.c 3d22f21c4701f62c1a191c6b6d17552fb1b593fe9a97c0613cca05ab104a9a51
  F src/callback.c d0b853dd413255d2e337b34545e54d888ea02f20da5ad0e63585b389624c4a6c
  F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 -F src/ctime.c 6a77ec9e0eb87aea929e002c816298907e337094a7b556898ae2d1e6be209f90
 +F src/ctime.c 6892999ee100bd72b64f84dd7a8f737817d72872648705fbf8ed9575e1f1dd1a
- F src/date.c 6c408fdd2e9ddf6e8431aba76315a2d061bea2cec8fbb75e25d7c1ba08274712
+ F src/date.c b29b349d277e3d579dcc295b24c0a2caed83fd8f090a9f7cbe6070c0fd662384
  F src/dbpage.c 8a01e865bf8bc6d7b1844b4314443a6436c07c3efe1d488ed89e81719047833a
  F src/dbstat.c 793deaf88a0904f88285d93d6713c636d55ede0ffd9f08d10f4ea825531d367f
  F src/delete.c 11000121c4281c0bce4e41db29addfaea0038eaa127ece02557c9207bc3e541d
@@@ -495,8 -495,8 +495,8 @@@ F src/in-operator.md 10cd8f4bcd225a3251
  F src/insert.c 8e4211d04eb460c0694d486c6ba1c068d468c6f653c3f237869a802ad82854de
  F src/legacy.c d7874bc885906868cd51e6c2156698f2754f02d9eee1bae2d687323c3ca8e5aa
  F src/loadext.c b179df50e6e8bb0c36c149e95d958d49bd8c6c7469e59c01b53d164360bc6c32
- F src/main.c ed15d7e6b73ac081cf354b3544e7792a775492b19b2abf95e9f8be06e8c1c5e5
- F src/malloc.c eaa4dc9602ce28b077f7de2eb275db2be270c5cc56d7fec5466301bd9b80e2f5
 -F src/main.c 2e076b6dc1f8ab69c7fc604e8af88ab138a64c0616826361e254cee55bcba4e8
++F src/main.c 28f43ecf5132240b43be1c834329b2139bb9b8c42cd401159ce70fef8c68ca69
+ F src/malloc.c cabfef0d725e04c8abfe0231a556ed8b78bf329dcc3fddbf903f6cdcd53cf4e6
  F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
  F src/mem1.c c12a42539b1ba105e3707d0e628ad70e611040d8f5e38cf942cee30c867083de
  F src/mem2.c f1940d9e91948dd6a908fbb9ce3835c36b5d83c3
@@@ -603,19 -603,18 +603,19 @@@ F src/upsert.c 2920de71b20f04fe25eb00b6
  F src/utf.c 95fb6e03a5ca679045c5adccd05380f0addccabef5911abddcb06af069500ab7
  F src/util.c a285c1e026907b69fa2592bd05047a565a1d8a1aef2b73c924b6a8ffe772871a
  F src/vacuum.c 813b510ba887fee6492bcb11f2bf77d7eb58b232b83649136372e0a2fc17f4b9
- F src/vdbe.c c1c123c6248fa88940b932a00bcc75056921b6d046d45a82566cb97415d2299c
+ F src/vdbe.c 972999395eee88702091fb5d50cf4effd07889c371807d222a7f517388e6378e
 -F src/vdbe.h 51282fbe819ee0e8eeeaab176240860d334c20a12b14f3b363e7f1a4e05d60b9
 -F src/vdbeInt.h 0b728ee662862a38b1912af741e2ac64f524de3c77aa86cf4306c42bdcd9de59
 +F src/vdbe.h 07b8c636a87df8b6e58f29d6badd7f10d5844353deff1d7c88ed1c2bfe3bbd35
 +F src/vdbeInt.h 5f36e2261731e6a39c66c6902634e474d4a98ed14ca10be6dea5c3776ece4342
- F src/vdbeapi.c 1252d80c548711e47a6d84dae88ed4e95d3fbb4e7bd0eaa1347299af7efddf02
- F src/vdbeaux.c 2b81b42788e718786817fe339eb728e81401542fb221c7f95b24ce39a735eff8
+ F src/vdbeapi.c d176ee7251d5344de7bb2a0d2dd0fe536834e5843d9bc2389e0f5cdcd5374141
 -F src/vdbeaux.c 8349559e72bf0cfa2258b1159b004ec4d1717a054d2e1829c8cc897c32da8752
++F src/vdbeaux.c 07b697900b22bd2717cee24ff4cfc3c7433a7e1c62979e687a0d23f2668b9904
  F src/vdbeblob.c 253ed82894924c362a7fa3079551d3554cd1cdace39aa833da77d3bc67e7c1b1
  F src/vdbemem.c 39b942ecca179f4f30a32b54579a85d74ccaefa5af2a0ad2700abe5ef0768b22
  F src/vdbesort.c 2be76d26998ce2b3324cdcc9f6443728e54b6c7677c553ad909c7d7cfab587df
  F src/vdbetrace.c fa3bf238002f0bbbdfb66cc8afb0cea284ff9f148d6439bc1f6f2b4c3b7143f0
 +F src/vdbevtab.c 3f7fd339425729f6cef36ef0bc576bf42641d2a664c746b54a6e2c045ae1a248
  F src/vtab.c 7b704a90515a239c6cdba6a66b1bb3a385e62326cceb5ecb05ec7a091d6b8515
  F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
- F src/wal.c 697424314e40d99f93f548c7bfa526c10e87f4bdf64d5a76a96b999dd7133ebc
+ F src/wal.c ea8dad28bb0e2b85ac1ab7618968687ff5fd522af8a1a38d6960ec176ebc8ee6
  F src/wal.h 606292549f5a7be50b6227bd685fa76e3a4affad71bb8ac5ce4cb5c79f6a176a
  F src/walker.c 7c429c694abd12413a5c17aec9f47cfe9eba6807e6b0a32df883e8e3a14835ed
  F src/where.c 9546c82056e8cdb27291f98cf1adca5d271240b399bb97b32f77fc2bea6146c9
@@@ -1861,7 -1860,7 +1861,7 @@@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a9
  F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
  F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
  F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
- P d7db09101878102e192ee7a81437e8f6f2e317ddf110852673a2e81d1f80ae0e
- R 97037e53b3358656d7c80bf175451cab
 -P fbd9378727141848ba2f5a8eee3076ecbd315e4a87b264c6d890103d56b2e4bc
 -R c8b295e5bd68ca95045f3500e6ef50d6
 -U dan
 -Z 1be00e3678658e7590a9c61fafe2f4aa
++P 6283c677d57220e54375a6463f453c6d068e042263558df16cff1055d1b0d3f5 a49f8ec552bede7da731e0571ccf49de1a30e7be3a5673150436c8b411ba6ffc
++R 3169d95f383859bfa6626ea7d2fa0b6d
 +U drh
- Z 77036c852e70ef7951f1cc73bc25be37
++Z 88bed112404a5cfaec60f425ff57b550

diff --cc manifest.uuid
index 27ef553c8eceb29824219d22c92d44e1c9b4341e,ca0e7838139881cac0d96dc43f037aba170c7491..cd1792d40d235f81493fc36b1cff81e24c122a10
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 6283c677d57220e54375a6463f453c6d068e042263558df16cff1055d1b0d3f5
 -a49f8ec552bede7da731e0571ccf49de1a30e7be3a5673150436c8b411ba6ffc
++d1731385c077f298b0cf654d6183ed40f7e5c07e4e2ab7f69109cf951ce99d9e

diff --cc src/main.c
Simple merge

diff --cc src/vdbeaux.c
index c0bb9c77f8b683eeccac947e93fb0429156d7356,cfddc0f614fe5ef6c71a8ad4d0441c440458f4b9..7be46018333c70bef5398cb4cec7a93a0f6a1dcd
--- 1/src/vdbeaux.c
--- 2/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@@ -2131,16 -2027,73 +2131,16 @@@ int sqlite3VdbeList
      ** cells.  */
      assert( p->nMem>9 );
      pSub = &p->aMem[9];
 -    if( pSub->flags&MEM_Blob ){
 -      /* On the first call to sqlite3_step(), pSub will hold a NULL.  It is
 -      ** initialized to a BLOB by the P4_SUBPROGRAM processing logic below */
 -      nSub = pSub->n/sizeof(Vdbe*);
 -      apSub = (SubProgram **)pSub->z;
 -    }
 -    for(i=0; i<nSub; i++){
 -      nRow += apSub[i]->nOp;
 -    }
 +  }else{
 +    pSub = 0;
    }
  
 -  while(1){  /* Loop exits via break */
 -    i = p->pc++;
 -    if( i>=nRow ){
 -      p->rc = SQLITE_OK;
 -      rc = SQLITE_DONE;
 -      break;
 -    }
 -    if( i<p->nOp ){
 -      /* The output line number is small enough that we are still in the
 -      ** main program. */
 -      pOp = &p->aOp[i];
 -    }else{
 -      /* We are currently listing subprograms.  Figure out which one and
 -      ** pick up the appropriate opcode. */
 -      int j;
 -      i -= p->nOp;
 -      assert( apSub!=0 );
 -      assert( nSub>0 );
 -      for(j=0; i>=apSub[j]->nOp; j++){
 -        i -= apSub[j]->nOp;
 -        assert( i<apSub[j]->nOp || j+1<nSub );
 -      }
 -      pOp = &apSub[j]->aOp[i];
 -    }
 -
 -    /* When an OP_Program opcode is encounter (the only opcode that has
 -    ** a P4_SUBPROGRAM argument), expand the size of the array of subprograms
 -    ** kept in p->aMem[9].z to hold the new program - assuming this subprogram
 -    ** has not already been seen.
 -    */
 -    if( bListSubprogs && pOp->p4type==P4_SUBPROGRAM ){
 -      int nByte = (nSub+1)*sizeof(SubProgram*);
 -      int j;
 -      for(j=0; j<nSub; j++){
 -        if( apSub[j]==pOp->p4.pProgram ) break;
 -      }
 -      if( j==nSub ){
 -        p->rc = sqlite3VdbeMemGrow(pSub, nByte, nSub!=0);
 -        if( p->rc!=SQLITE_OK ){
 -          rc = SQLITE_ERROR;
 -          break;
 -        }
 -        apSub = (SubProgram **)pSub->z;
 -        apSub[nSub++] = pOp->p4.pProgram;
 -        pSub->flags |= MEM_Blob;
 -        pSub->n = nSub*sizeof(SubProgram*);
 -        nRow += pOp->p4.pProgram->nOp;
 -      }
 -    }
 -    if( p->explain<2 ) break;
 -    if( pOp->opcode==OP_Explain ) break;
 -    if( pOp->opcode==OP_Init && p->pc>1 ) break;
 -  }
 +  /* Figure out which opcode is next to display */
 +  rc = sqlite3VdbeNextOpcode(p, pSub, p->explain==2, &p->pc, &i, &aOp);
  
    if( rc==SQLITE_OK ){
-     if( db->u1.isInterrupted ){
 +    pOp = aOp + i;
+     if( AtomicLoad(&db->u1.isInterrupted) ){
        p->rc = SQLITE_INTERRUPT;
        rc = SQLITE_ERROR;
        sqlite3VdbeError(p, sqlite3ErrStr(p->rc));