SQLite

}
static Mem *out2Prerelease(Vdbe *p, VdbeOp *pOp){
  Mem *pOut;
  assert( pOp->p2>0 );
  assert( pOp->p2<=(p->nMem-p->nCursor) );
  pOut = &p->aMem[pOp->p2];
  memAboutToChange(p, pOut);
  if( VdbeMemDynamicOrSubtype(pOut) ){
    return out2PrereleaseWithClear(pOut);
  }else{
    pOut->flags = MEM_Int;
    return pOut;
  }
}

  /* Extract the content for the p2+1-th column.  Control can only
  ** reach this point if aOffset[p2], aOffset[p2+1], and pC->aType[p2] are
  ** all valid.
  */
  assert( p2<pC->nHdrParsed );
  assert( rc==SQLITE_OK );
  assert( sqlite3VdbeCheckMemInvariants(pDest) );
  if( VdbeMemDynamicOrSubtype(pDest) ) sqlite3VdbeMemSetNull(pDest);
  assert( t==pC->aType[p2] );
  pDest->enc = encoding;
  if( pC->szRow>=aOffset[p2+1] ){
    /* This is the common case where the desired content fits on the original
    ** page - where the content is not on an overflow page */
    zData = pC->aRow + aOffset[p2];
    if( t<12 ){

*/
#define MEM_Term      0x0200   /* String rep is nul terminated */
#define MEM_Dyn       0x0400   /* Need to call Mem.xDel() on Mem.z */
#define MEM_Static    0x0800   /* Mem.z points to a static string */
#define MEM_Ephem     0x1000   /* Mem.z points to an ephemeral string */
#define MEM_Agg       0x2000   /* Mem.z points to an agg function context */
#define MEM_Zero      0x4000   /* Mem.i contains count of 0s appended to blob */
#define MEM_Subtype   0x8000   /* Mem.eSubtype might be non-zero */
#ifdef SQLITE_OMIT_INCRBLOB
  #undef MEM_Zero
  #define MEM_Zero 0x0000
#endif

/* Return TRUE if Mem X contains dynamically allocated content - anything
** that needs to be deallocated to avoid a leak.
*/
#define VdbeMemDynamic(X)  \
  (((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame))!=0)

/* Return TRUE if MEM x contains dynamically allocated content, or if
** x might have a non-zero subtype
*/
#define VdbeMemDynamicOrSubtype(X)  \
  (((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame|MEM_Subtype))!=0)


/*
** Clear any existing type flags from a Mem and replace them with f
*/
#define MemSetTypeFlag(p, f) \
   ((p)->flags = ((p)->flags&~(MEM_TypeMask|MEM_Zero))|f)

double sqlite3VdbeRealValue(Mem*);
void sqlite3VdbeIntegerAffinity(Mem*);
int sqlite3VdbeMemRealify(Mem*);
int sqlite3VdbeMemNumerify(Mem*);
void sqlite3VdbeMemCast(Mem*,u8,u8);
int sqlite3VdbeMemFromBtree(BtCursor*,u32,u32,int,Mem*);
void sqlite3VdbeMemRelease(Mem *p);


int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
const char *sqlite3OpcodeName(int);
int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
int sqlite3VdbeMemClearAndResize(Mem *pMem, int n);
int sqlite3VdbeCloseStatement(Vdbe *, int);
void sqlite3VdbeFrameDelete(VdbeFrame*);
int sqlite3VdbeFrameRestore(VdbeFrame *);

  sqlite3VdbeMemSetInt64(pCtx->pOut, iVal);
}
void sqlite3_result_null(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  sqlite3VdbeMemSetNull(pCtx->pOut);
}
void sqlite3_result_subtype(sqlite3_context *pCtx, unsigned int eSubtype){
  Mem *pOut = pCtx->pOut;
  assert( sqlite3_mutex_held(pOut->db->mutex) );
  pOut->eSubtype = eSubtype & 0xff;
  pOut->flags |= MEM_Subtype;
}
void sqlite3_result_text(
  sqlite3_context *pCtx, 
  const char *z, 
  int n,
  void (*xDel)(void *)
){

**
** This is a helper routine for sqlite3VdbeMemSetNull() and
** for sqlite3VdbeMemRelease().  Use those other routines as the
** entry point for releasing Mem resources.
*/
static SQLITE_NOINLINE void vdbeMemClearExternAndSetNull(Mem *p){
  assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );
  assert( VdbeMemDynamicOrSubtype(p) );
  if( p->flags&MEM_Agg ){
    sqlite3VdbeMemFinalize(p, p->u.pDef);
    assert( (p->flags & MEM_Agg)==0 );
    testcase( p->flags & MEM_Dyn );
  }
  if( p->flags&MEM_Dyn ){
    assert( (p->flags&MEM_RowSet)==0 );
    assert( p->xDel!=SQLITE_DYNAMIC && p->xDel!=0 );
    p->xDel((void *)p->z);
  }else if( p->flags&MEM_RowSet ){
    sqlite3RowSetClear(p->u.pRowSet);
  }else if( p->flags&MEM_Frame ){
    VdbeFrame *pFrame = p->u.pFrame;
    pFrame->pParent = pFrame->v->pDelFrame;
    pFrame->v->pDelFrame = pFrame;
  }
  p->flags = MEM_Null;
  p->eSubtype = 0;
}

/*
** Release memory held by the Mem p, both external memory cleared
** by p->xDel and memory in p->zMalloc.
**
** This is a helper routine invoked by sqlite3VdbeMemRelease() in
** the unusual case where there really is memory in p that needs
** to be freed.
*/
static SQLITE_NOINLINE void vdbeMemClear(Mem *p){
  if( VdbeMemDynamicOrSubtype(p) ){
    vdbeMemClearExternAndSetNull(p);
  }
  if( p->szMalloc ){
    sqlite3DbFree(p->db, p->zMalloc);
    p->szMalloc = 0;
  }
  p->z = 0;

** reset a Mem back to its minimum memory utilization.
**
** Use sqlite3VdbeMemSetNull() to release just the Mem.xDel space
** prior to inserting new content into the Mem.
*/
void sqlite3VdbeMemRelease(Mem *p){
  assert( sqlite3VdbeCheckMemInvariants(p) );
  if( VdbeMemDynamicOrSubtype(p) || p->szMalloc ){
    vdbeMemClear(p);
  }
}

/*
** Convert a 64-bit IEEE double into a 64-bit signed integer.
** If the double is out of range of a 64-bit signed integer then

** routine to invoke the destructor and deallocates Mem.zMalloc.
**
** Use this routine to reset the Mem prior to insert a new value.
**
** Use sqlite3VdbeMemRelease() to complete erase the Mem prior to abandoning it.
*/
void sqlite3VdbeMemSetNull(Mem *pMem){
  if( VdbeMemDynamicOrSubtype(pMem) ){
    vdbeMemClearExternAndSetNull(pMem);
  }else{
    pMem->flags = MEM_Null;
  }
}
void sqlite3ValueSetNull(sqlite3_value *p){
  sqlite3VdbeMemSetNull((Mem*)p); 

}

/*
** Delete any previous value and set the value stored in *pMem to val,
** manifest type INTEGER.
*/
void sqlite3VdbeMemSetInt64(Mem *pMem, i64 val){
  if( VdbeMemDynamicOrSubtype(pMem) ){
    vdbeReleaseAndSetInt64(pMem, val);
  }else{
    pMem->u.i = val;
    pMem->flags = MEM_Int;
  }
}

   WHERE rowid BETWEEN 31 AND 39 AND rowid%2==1;
} {{{"n31":32.5,"n33":33,"n35":35,"n37":null,"n39":"orange"}}}
do_execsql_test json103-220 {
  SELECT b, json_group_object(c,a) FROM t1
   WHERE rowid<7 GROUP BY b ORDER BY b;
} {0 {{"n3":3,"n6":6}} 1 {{"n1":1,"n4":4}} 2 {{"n2":2,"n5":5}}}

# ticket https://www.sqlite.org/src/info/f45ac567eaa9f93c 2016-01-30
# Invalid JSON generated by json_group_array() 
#
# The underlying problem is a failure to reset Mem.eSubtype
#
do_execsql_test json103-300 {
  DROP TABLE IF EXISTS t1;
  CREATE TABLE t1(x);
  INSERT INTO t1 VALUES(1),('abc');
  SELECT
     json_group_array(x),
     json_group_array(json_object('x',x))
    FROM t1;
} {{[1,"abc"]} {[{"x":1},{"x":"abc"}]}}

finish_test