Index: src/vdbe.c
==================================================================
--- src/vdbe.c
+++ src/vdbe.c
@@ -3368,63 +3368,82 @@
** temporary tables, and P3>1 means used the corresponding attached
** database. Give the new cursor an identifier of P1. The P1
** values need not be contiguous but all P1 values should be small integers.
** It is an error for P1 to be negative.
**
-** If P5!=0 then use the content of register P2 as the root page, not
-** the value of P2 itself.
-**
-** There will be a read lock on the database whenever there is an
-** open cursor. If the database was unlocked prior to this instruction
-** then a read lock is acquired as part of this instruction. A read
-** lock allows other processes to read the database but prohibits
-** any other process from modifying the database. The read lock is
-** released when all cursors are closed. If this instruction attempts
-** to get a read lock but fails, the script terminates with an
-** SQLITE_BUSY error code.
+** Allowed P5 bits:
+**
+** - 0x02 OPFLAG_SEEKEQ: This cursor will only be used for
+** equality lookups (implemented as a pair of opcodes OP_SeekGE/OP_IdxGT
+** of OP_SeekLE/OP_IdxGT)
+**
**
** The P4 value may be either an integer (P4_INT32) or a pointer to
** a KeyInfo structure (P4_KEYINFO). If it is a pointer to a KeyInfo
-** structure, then said structure defines the content and collating
-** sequence of the index being opened. Otherwise, if P4 is an integer
-** value, it is set to the number of columns in the table.
+** object, then table being opened must be an [index b-tree] where the
+** KeyInfo object defines the content and collating
+** sequence of that index b-tree. Otherwise, if P4 is an integer
+** value, then the table being opened must be a [table b-tree] with a
+** number of columns no less than the value of P4.
**
** See also: OpenWrite, ReopenIdx
*/
/* Opcode: ReopenIdx P1 P2 P3 P4 P5
** Synopsis: root=P2 iDb=P3
**
-** The ReopenIdx opcode works exactly like ReadOpen except that it first
-** checks to see if the cursor on P1 is already open with a root page
-** number of P2 and if it is this opcode becomes a no-op. In other words,
+** The ReopenIdx opcode works like OP_OpenRead except that it first
+** checks to see if the cursor on P1 is already open on the same
+** b-tree and if it is this opcode becomes a no-op. In other words,
** if the cursor is already open, do not reopen it.
**
-** The ReopenIdx opcode may only be used with P5==0 and with P4 being
-** a P4_KEYINFO object. Furthermore, the P3 value must be the same as
-** every other ReopenIdx or OpenRead for the same cursor number.
+** The ReopenIdx opcode may only be used with P5==0 or P5==OPFLAG_SEEKEQ
+** and with P4 being a P4_KEYINFO object. Furthermore, the P3 value must
+** be the same as every other ReopenIdx or OpenRead for the same cursor
+** number.
**
-** See the OpenRead opcode documentation for additional information.
+** Allowed P5 bits:
+**
+** - 0x02 OPFLAG_SEEKEQ: This cursor will only be used for
+** equality lookups (implemented as a pair of opcodes OP_SeekGE/OP_IdxGT
+** of OP_SeekLE/OP_IdxGT)
+**
+**
+** See also: OP_OpenRead, OP_OpenWrite
*/
/* Opcode: OpenWrite P1 P2 P3 P4 P5
** Synopsis: root=P2 iDb=P3
**
** Open a read/write cursor named P1 on the table or index whose root
-** page is P2. Or if P5!=0 use the content of register P2 to find the
-** root page.
+** page is P2 (or whose root page is held in register P2 if the
+** OPFLAG_P2ISREG bit is set in P5 - see below).
**
** The P4 value may be either an integer (P4_INT32) or a pointer to
** a KeyInfo structure (P4_KEYINFO). If it is a pointer to a KeyInfo
-** structure, then said structure defines the content and collating
-** sequence of the index being opened. Otherwise, if P4 is an integer
-** value, it is set to the number of columns in the table, or to the
-** largest index of any column of the table that is actually used.
-**
-** This instruction works just like OpenRead except that it opens the cursor
-** in read/write mode. For a given table, there can be one or more read-only
-** cursors or a single read/write cursor but not both.
-**
-** See also OpenRead.
+** object, then table being opened must be an [index b-tree] where the
+** KeyInfo object defines the content and collating
+** sequence of that index b-tree. Otherwise, if P4 is an integer
+** value, then the table being opened must be a [table b-tree] with a
+** number of columns no less than the value of P4.
+**
+** Allowed P5 bits:
+**
+** - 0x02 OPFLAG_SEEKEQ: This cursor will only be used for
+** equality lookups (implemented as a pair of opcodes OP_SeekGE/OP_IdxGT
+** of OP_SeekLE/OP_IdxGT)
+**
- 0x08 OPFLAG_FORDELETE: This cursor is used only to seek
+** and subsequently delete entries in an index btree. This is a
+** hint to the storage engine that the storage engine is allowed to
+** ignore. The hint is not used by the official SQLite b*tree storage
+** engine, but is used by COMDB2.
+**
- 0x10 OPFLAG_P2ISREG: Use the content of register P2
+** as the root page, not the value of P2 itself.
+**
+**
+** This instruction works like OpenRead except that it opens the cursor
+** in read/write mode.
+**
+** See also: OP_OpenRead, OP_ReopenIdx
*/
case OP_ReopenIdx: {
int nField;
KeyInfo *pKeyInfo;
int p2;
@@ -3476,10 +3495,11 @@
wrFlag = 0;
}
if( pOp->p5 & OPFLAG_P2ISREG ){
assert( p2>0 );
assert( p2<=(p->nMem+1 - p->nCursor) );
+ assert( pOp->opcode==OP_OpenWrite );
pIn2 = &aMem[p2];
assert( memIsValid(pIn2) );
assert( (pIn2->flags & MEM_Int)!=0 );
sqlite3VdbeMemIntegerify(pIn2);
p2 = (int)pIn2->u.i;