Allow instruction OP_OpenDup to duplicate cursors created by OP_OpenDup, as well as by OP_OpenEphemeral.

FossilOrigin-Name: b8de980b2fb78088ef74e053cb987bb84319d13dc96ce1e89baaaa3fe8cf1efc

manifest

@@ -1,5 +1,5 @@
-C Version\s3.35.2
+C Allow\sinstruction\sOP_OpenDup\sto\sduplicate\scursors\screated\sby\sOP_OpenDup,\sas\swell\sas\sby\sOP_OpenEphemeral.
-D 2021-03-17T19:07:21.223
+D 2021-03-18T13:42:53.871
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -483,8 +483,8 @@ F src/auth.c 08954fdc4cc2da5264ba5b75cfd90b67a6fc7d1710a02ccf917c38eadec77853
 F src/backup.c 3014889fa06e20e6adfa0d07b60097eec1f6e5b06671625f476a714d2356513d
 F src/bitvec.c 17ea48eff8ba979f1f5b04cc484c7bb2be632f33
 F src/btmutex.c 8acc2f464ee76324bf13310df5692a262b801808984c1b79defb2503bbafadb6
-F src/btree.c bafa3a2e8b6622a3aa8791f90c8ecc70e8ae551ba9023f865213890f5b8a8994
+F src/btree.c 83cb92554f14752d1446ecebf9d2b38292d36af23d1b422862653192b742e1b7
-F src/btree.h 096cc53baa58be22b02c896d1cf933c38cfc6d65f9253c1367ece8cc88a24de5
+F src/btree.h a25ab8dfe82764e0449e12091f4dbedcf2995a70db6a27e224d1f3772a0d640c
 F src/btreeInt.h 7614cae30f95b6aed0c7cac7718276a55cfe2c77058cbfd8bef5b75329757331
 F src/build.c fec73c39d756f31d35ccbaa80fe1e040a8d675a318d4d30f41c444167bf3b860
 F src/callback.c d0b853dd413255d2e337b34545e54d888ea02f20da5ad0e63585b389624c4a6c
@@ -614,7 +614,7 @@ F src/upsert.c df8f1727d62b5987c4fd302cd4d7c0c84ae57cd65683c5a34a740dfe24039235
 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0
 F src/util.c 41c7a72da1df47864faa378a1c720b38adb288c6838cb6be5594511b6287a048
 F src/vacuum.c 492422c1463c076473bae1858799c7a0a5fe87a133d1223239447c422cd26286
-F src/vdbe.c b79b222f07690874d436eef4ad5e76845b2796e7094b1d0545cc94333f0d8e50
+F src/vdbe.c ae4ebb8762fc1b30f11a0498eba74c193f052c6724f73ffb63548875200813c6
 F src/vdbe.h 25dabb25c7e157b84e59260cfb5b466c3ac103ede9f36f4db371332c47601abe
 F src/vdbeInt.h 3df118924e1711f1bbc8e30c46260d0ab6c3b029b32dd411f789111f76434f3c
 F src/vdbeapi.c 4a43e303ec3354c785f453e881521969378e85628278ab74ba4a9df790c0d93b
@@ -1910,9 +1910,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 0ed7eb9115510511f13dca715bb2b178580648517d8d30436a992d70a2e85ac1
+P ea80f3002f4120f5dcee76e8779dfdc88e1e096c5cdd06904c20fd26d50c3827
-R 6b9cbc5338ab96ec85af6f269ca8689c
+R 5690d05e7243d41ceb9332de8bdd3707
-T +sym-release *
+T *branch * opendup-fix
-T +sym-version-3.35.2 *
+T *sym-opendup-fix *
-U drh
+T -sym-trunk *
-Z df8a52cb5f4a5da779c9bf4ff3cf1b0f
+U dan
+Z fd7ffe22c065e32af24a29a1b9c91b9f

manifest.uuid

@@ -1 +1 @@
-ea80f3002f4120f5dcee76e8779dfdc88e1e096c5cdd06904c20fd26d50c3827
+b8de980b2fb78088ef74e053cb987bb84319d13dc96ce1e89baaaa3fe8cf1efc

src/btree.c

@@ -10705,6 +10705,14 @@ int sqlite3BtreeIsReadonly(Btree *p){
 */
 int sqlite3HeaderSizeBtree(void){ return ROUND8(sizeof(MemPage)); }
 
+/*
+** Return the Btree object used to open the cursor provided as an
+** argument.
+*/
+Btree *sqlite3BtreeGetBtree(BtCursor *pCsr){
+  return pCsr->pBtree;
+}
+
 #if !defined(SQLITE_OMIT_SHARED_CACHE)
 /*
 ** Return true if the Btree passed as the only argument is sharable.

src/btree.h

@@ -363,6 +363,7 @@ void sqlite3BtreeCursorList(Btree*);
 #endif
 
 int sqlite3BtreeTransferRow(BtCursor*, BtCursor*, i64);
+Btree *sqlite3BtreeGetBtree(BtCursor*);
 
 /*
 ** If we are not using shared cache, then there is no need to

src/vdbe.c

@@ -3873,7 +3873,7 @@ case OP_OpenDup: {
 
   pOrig = p->apCsr[pOp->p2];
   assert( pOrig );
-  assert( pOrig->pBtx!=0 );  /* Only ephemeral cursors can be duplicated */
+  assert( pOrig->isEphemeral );  /* Only ephemeral cursors can be duplicated */
 
   pCx = allocateCursor(p, pOp->p1, pOrig->nField, -1, CURTYPE_BTREE);
   if( pCx==0 ) goto no_mem;
@@ -3883,8 +3883,9 @@ case OP_OpenDup: {
   pCx->isTable = pOrig->isTable;
   pCx->pgnoRoot = pOrig->pgnoRoot;
   pCx->isOrdered = pOrig->isOrdered;
-  rc = sqlite3BtreeCursor(pOrig->pBtx, pCx->pgnoRoot, BTREE_WRCSR,
+  rc = sqlite3BtreeCursor(sqlite3BtreeGetBtree(pOrig->uc.pCursor),
-                          pCx->pKeyInfo, pCx->uc.pCursor);
+      pCx->pgnoRoot, BTREE_WRCSR, pCx->pKeyInfo, pCx->uc.pCursor
+  );
   /* The sqlite3BtreeCursor() routine can only fail for the first cursor
   ** opened for a database.  Since there is already an open cursor when this
   ** opcode is run, the sqlite3BtreeCursor() cannot fail */