static GBOX*
parse_geohash(char *geohash, int precision)
{
	GBOX *box = NULL;
	double lat[2], lon[2];

	POSTGIS_DEBUG(2, "parse_geohash called.");

	if (NULL == geohash)
	{
		geohash_lwpgerror("invalid GeoHash representation", 2);
	}

	decode_geohash_bbox(geohash, lat, lon, precision);

	POSTGIS_DEBUGF(2, "ST_Box2dFromGeoHash sw: %.20f, %.20f", lon[0], lat[0]);
	POSTGIS_DEBUGF(2, "ST_Box2dFromGeoHash ne: %.20f, %.20f", lon[1], lat[1]);

	box = gbox_new(gflags(0, 0, 1));

	box->xmin = lon[0];
	box->ymin = lat[0];

	box->xmax = lon[1];
	box->ymax = lat[1];

	POSTGIS_DEBUG(2, "parse_geohash finished.");
	return box;
}

Datum gserialized_gist_penalty_2d(PG_FUNCTION_ARGS)
{
	GISTENTRY *origentry = (GISTENTRY*) PG_GETARG_POINTER(0);
	GISTENTRY *newentry = (GISTENTRY*) PG_GETARG_POINTER(1);
	float *result = (float*) PG_GETARG_POINTER(2);
	BOX2DF *gbox_index_orig, *gbox_index_new;
	float size_union, size_orig;

	POSTGIS_DEBUG(4, "[GIST] 'penalty' function called");

	gbox_index_orig = (BOX2DF*)DatumGetPointer(origentry->key);
	gbox_index_new = (BOX2DF*)DatumGetPointer(newentry->key);

	/* Drop out if we're dealing with null inputs. Shouldn't happen. */
	if ( (gbox_index_orig == NULL) && (gbox_index_new == NULL) )
	{
		POSTGIS_DEBUG(4, "[GIST] both inputs NULL! returning penalty of zero");
		*result = 0.0;
		PG_RETURN_FLOAT8(*result);
	}

	/* Calculate the size difference of the boxes. */
	size_union = box2df_union_size(gbox_index_orig, gbox_index_new);
	size_orig = box2df_size(gbox_index_orig);
	*result = size_union - size_orig;

	POSTGIS_DEBUGF(4, "[GIST] 'penalty', union size (%.12f), original size (%.12f), penalty (%.12f)", size_union, size_orig, *result);

	PG_RETURN_POINTER(result);
}

static LWGEOM*
parse_geojson_linestring(json_object *geojson, bool *hasz,  int *root_srid)
{
	LWGEOM *geom;
	POINTARRAY *pa;
	json_object* points = NULL;
	int i = 0;

	POSTGIS_DEBUG(2, "parse_geojson_linestring called.");

	points = findMemberByName( geojson, "coordinates" );
	if ( ! points )
		geojson_lwerror("Unable to find 'coordinates' in GeoJSON string", 4);

	pa = ptarray_construct_empty(1, 0, 1);

	if( json_type_array == json_object_get_type( points ) )
	{
		const int nPoints = json_object_array_length( points );
		for(i = 0; i < nPoints; ++i)
		{
			json_object* coords = NULL;
			coords = json_object_array_get_idx( points, i );
			parse_geojson_coord(coords, hasz, pa);
		}
	}

	geom = (LWGEOM *) lwline_construct(*root_srid, NULL, pa);

	POSTGIS_DEBUG(2, "parse_geojson_linestring finished.");
	return geom;
}

/*
** Peak into a geography to find the bounding box. If the
** box is there, copy it out and return it. If not, calculate the box from the
** full geography and return the box based on that. If no box is available,
** return G_FAILURE, otherwise G_SUCCESS.
*/
int geography_gidx(GSERIALIZED *g, GIDX *gidx)
{
	int result = G_SUCCESS;

	POSTGIS_DEBUG(4, "entered function");

	POSTGIS_DEBUGF(4, "got flags %d", g->flags);

	if ( FLAGS_GET_BBOX(g->flags) && FLAGS_GET_GEODETIC(g->flags) )
	{
		const size_t size = 2 * 3 * sizeof(float);
		POSTGIS_DEBUG(4, "copying box out of serialization");
		memcpy(gidx->c, g->data, size);
		SET_VARSIZE(gidx, VARHDRSZ + size);
	}
	else
	{
		GBOX gbox;
		POSTGIS_DEBUG(4, "calculating new box from scratch");
		if ( gserialized_calculate_gbox_geocentric_p(g, &gbox) == G_FAILURE )
		{
			POSTGIS_DEBUG(4, "calculated null bbox, returning null");
			return G_FAILURE;
		}
		result = gidx_from_gbox_p(gbox, gidx);
	}
	if ( result == G_SUCCESS )
	{
		POSTGIS_DEBUGF(4, "got gidx %s", gidx_to_string(gidx));
	}

	return result;
}

Datum LWGEOM_recv(PG_FUNCTION_ARGS)
{
	StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
	int32 geom_typmod = -1;
	GSERIALIZED *geom;
	LWGEOM *lwgeom;

	if ( (PG_NARGS()>2) && (!PG_ARGISNULL(2)) ) {
		geom_typmod = PG_GETARG_INT32(2);
	}
	
	lwgeom = lwgeom_from_wkb((uint8_t*)buf->data, buf->len, LW_PARSER_CHECK_ALL);

	if ( lwgeom_needs_bbox(lwgeom) )
		lwgeom_add_bbox(lwgeom);

	/* Set cursor to the end of buffer (so the backend is happy) */
	buf->cursor = buf->len;

	geom = geometry_serialize(lwgeom);
	lwgeom_free(lwgeom);

	if ( geom_typmod >= 0 )
	{
		postgis_valid_typmod(geom, geom_typmod);
		POSTGIS_DEBUG(3, "typmod and geometry were consistent");
	}
	else
	{
		POSTGIS_DEBUG(3, "typmod was -1");
	}

	
	PG_RETURN_POINTER(geom);
}

/**
* Peak into a #GSERIALIZED datum to find the bounding box. If the
* box is there, copy it out and return it. If not, calculate the box from the
* full object and return the box based on that. If no box is available,
* return #LW_FAILURE, otherwise #LW_SUCCESS.
*/
int 
gserialized_datum_get_gidx_p(Datum gsdatum, GIDX *gidx)
{
	GSERIALIZED *gpart;
	int result = LW_SUCCESS;

	POSTGIS_DEBUG(4, "entered function");

	/*
	** The most info we need is the 8 bytes of serialized header plus the 32 bytes
	** of floats necessary to hold the 8 floats of the largest XYZM index
	** bounding box, so 40 bytes.
	*/
	gpart = (GSERIALIZED*)PG_DETOAST_DATUM_SLICE(gsdatum, 0, 40);

	POSTGIS_DEBUGF(4, "got flags %d", gpart->flags);

	/* Do we even have a serialized bounding box? */
	if ( FLAGS_GET_BBOX(gpart->flags) )
	{
		/* Yes! Copy it out into the GIDX! */
		size_t size = gbox_serialized_size(gpart->flags);
		POSTGIS_DEBUG(4, "copying box out of serialization");
		memcpy(gidx->c, gpart->data, size);
		/* if M is present but Z is not, pad Z and shift M */
		if ( FLAGS_GET_M(gpart->flags) && ! FLAGS_GET_Z(gpart->flags) )
		{
			size += 2 * sizeof(float);
			GIDX_SET_MIN(gidx,3,GIDX_GET_MIN(gidx,2));
			GIDX_SET_MAX(gidx,3,GIDX_GET_MAX(gidx,2));
			GIDX_SET_MIN(gidx,2,-1*FLT_MAX);
			GIDX_SET_MAX(gidx,2,FLT_MAX);
		}
		SET_VARSIZE(gidx, VARHDRSZ + size);
		result = LW_SUCCESS;
	}
	else
	{
		/* No, we need to calculate it from the full object. */
		GSERIALIZED *g = (GSERIALIZED*)PG_DETOAST_DATUM(gsdatum);
		LWGEOM *lwgeom = lwgeom_from_gserialized(g);
		GBOX gbox;
		if ( lwgeom_calculate_gbox(lwgeom, &gbox) == LW_FAILURE )
		{
			POSTGIS_DEBUG(4, "could not calculate bbox, returning failure");
			lwgeom_free(lwgeom);
			return LW_FAILURE;
		}
		lwgeom_free(lwgeom);
		result = gidx_from_gbox_p(gbox, gidx);
	}
	
	if ( result == LW_SUCCESS )
	{
		POSTGIS_DEBUGF(4, "got gidx %s", gidx_to_string(gidx));
	}

	return result;
}

Datum geography_gist_consistent(PG_FUNCTION_ARGS)
{
	GISTENTRY *entry = (GISTENTRY*) PG_GETARG_POINTER(0);
	StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
	bool result;
	char gidxmem[GIDX_MAX_SIZE];
	GIDX *query_gbox_index = (GIDX*)gidxmem;

#if POSTGIS_PGSQL_VERSION >= 84
	/* PostgreSQL 8.4 and later require the RECHECK flag to be set here,
	   rather than being supplied as part of the operator class definition */
	bool *recheck = (bool *) PG_GETARG_POINTER(4);

	/* We set recheck to false to avoid repeatedly pulling every "possibly matched" geometry
	   out during index scans. For cases when the geometries are large, rechecking
	   can make things twice as slow. */
	*recheck = false;
#endif

	POSTGIS_DEBUG(4, "[GIST] 'consistent' function called");

	/* Quick sanity check on query argument. */
	if ( DatumGetPointer(PG_GETARG_DATUM(1)) == NULL )
	{
		POSTGIS_DEBUG(4, "[GIST] null query pointer (!?!), returning false");
		PG_RETURN_BOOL(FALSE); /* NULL query! This is screwy! */
	}

	/* Quick sanity check on entry key. */
	if ( DatumGetPointer(entry->key) == NULL )
	{
		POSTGIS_DEBUG(4, "[GIST] null index entry, returning false");
		PG_RETURN_BOOL(FALSE); /* NULL entry! */
	}

	/* Null box should never make this far. */
	if ( geography_datum_gidx(PG_GETARG_DATUM(1), query_gbox_index) == G_FAILURE )
	{
		POSTGIS_DEBUG(4, "[GIST] null query_gbox_index!");
		PG_RETURN_BOOL(FALSE);
	}

	/* Treat leaf node tests different from internal nodes */
	if (GIST_LEAF(entry))
	{
		result = geography_gist_consistent_leaf(
		             (GIDX*)DatumGetPointer(entry->key),
		             query_gbox_index, strategy);
	}
	else
	{
		result = geography_gist_consistent_internal(
		             (GIDX*)DatumGetPointer(entry->key),
		             query_gbox_index, strategy);
	}

	PG_RETURN_BOOL(result);
}

/*
 * return -1 iff point outside multipolygon
 * return 0 iff point on multipolygon boundary
 * return 1 iff point inside multipolygon
 */
int point_in_multipolygon(LWMPOLY *mpolygon, LWPOINT *point)
{
	int i, j, result, in_ring;
	POINT2D pt;

	POSTGIS_DEBUG(2, "point_in_polygon called.");

	getPoint2d_p(point->point, 0, &pt);
	/* assume bbox short-circuit has already been attempted */

	result = -1;

	for (j = 0; j < mpolygon->ngeoms; j++ )
	{

		LWPOLY *polygon = mpolygon->geoms[j];

		/* everything is outside of an empty polygon */
		if ( polygon->nrings == 0 ) continue;

		in_ring = point_in_ring(polygon->rings[0], &pt);
		if ( in_ring == -1) /* outside the exterior ring */
		{
			POSTGIS_DEBUG(3, "point_in_polygon: outside exterior ring.");
			continue;
		}
		if ( in_ring == 0 )
		{
			return 0;
		}

		result = in_ring;

		for (i=1; i<polygon->nrings; i++)
		{
			in_ring = point_in_ring(polygon->rings[i], &pt);
			if (in_ring == 1) /* inside a hole => outside the polygon */
			{
				POSTGIS_DEBUGF(3, "point_in_polygon: within hole %d.", i);
				result = -1;
				break;
			}
			if (in_ring == 0) /* on the edge of a hole */
			{
				POSTGIS_DEBUGF(3, "point_in_polygon: on edge of hole %d.", i);
				return 0;
			}
		}
		if ( result != -1)
		{
			return result;
		}
	}
	return result;
}

Datum lwgeom_lt(PG_FUNCTION_ARGS)
{
	GSERIALIZED *geom1 = (GSERIALIZED *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
	GSERIALIZED *geom2 = (GSERIALIZED *) PG_DETOAST_DATUM(PG_GETARG_DATUM(1));
	GBOX box1;
	GBOX box2;

	POSTGIS_DEBUG(2, "lwgeom_lt called");

	if (gserialized_get_srid(geom1) != gserialized_get_srid(geom2))
	{
		elog(BTREE_SRID_MISMATCH_SEVERITY,
		     "Operation on two GEOMETRIES with different SRIDs\n");
		PG_FREE_IF_COPY(geom1, 0);
		PG_FREE_IF_COPY(geom2, 1);
		PG_RETURN_NULL();
	}

	POSTGIS_DEBUG(3, "lwgeom_lt passed getSRID test");

	gserialized_get_gbox_p(geom1, &box1);
	gserialized_get_gbox_p(geom2, &box2);

	PG_FREE_IF_COPY(geom1, 0);
	PG_FREE_IF_COPY(geom2, 1);

	POSTGIS_DEBUG(3, "lwgeom_lt getbox2d_p passed");

	if  ( ! FPeq(box1.xmin , box2.xmin) )
	{
		if  (box1.xmin < box2.xmin)
			PG_RETURN_BOOL(TRUE);
	}

	if  ( ! FPeq(box1.ymin , box2.ymin) )
	{
		if  (box1.ymin < box2.ymin)
			PG_RETURN_BOOL(TRUE);
	}

	if  ( ! FPeq(box1.xmax , box2.xmax) )
	{
		if  (box1.xmax < box2.xmax)
			PG_RETURN_BOOL(TRUE);
	}

	if  ( ! FPeq(box1.ymax , box2.ymax) )
	{
		if  (box1.ymax < box2.ymax)
			PG_RETURN_BOOL(TRUE);
	}

	PG_RETURN_BOOL(FALSE);
}

static int
CircTreePIP(const CIRC_NODE* tree1, const GSERIALIZED* g1, const POINT4D* in_point)
{
    int tree1_type = gserialized_get_type(g1);
    GBOX gbox1;
    GEOGRAPHIC_POINT in_gpoint;
    POINT3D in_point3d;

    POSTGIS_DEBUGF(3, "tree1_type=%d", tree1_type);

    /* If the tree'ed argument is a polygon, do the P-i-P using the tree-based P-i-P */
    if ( tree1_type == POLYGONTYPE || tree1_type == MULTIPOLYGONTYPE )
    {
        POSTGIS_DEBUG(3, "tree is a polygon, using tree PiP");
        /* Need a gbox to calculate an outside point */
        if ( LW_FAILURE == gserialized_get_gbox_p(g1, &gbox1) )
        {
            LWGEOM* lwgeom1 = lwgeom_from_gserialized(g1);
            POSTGIS_DEBUG(3, "unable to read gbox from gserialized, calculating from scratch");
            lwgeom_calculate_gbox_geodetic(lwgeom1, &gbox1);
            lwgeom_free(lwgeom1);
        }

        /* Flip the candidate point into geographics */
        geographic_point_init(in_point->x, in_point->y, &in_gpoint);
        geog2cart(&in_gpoint, &in_point3d);

        /* If the candidate isn't in the tree box, it's not in the tree area */
        if ( ! gbox_contains_point3d(&gbox1, &in_point3d) )
        {
            POSTGIS_DEBUG(3, "in_point3d is not inside the tree gbox, CircTreePIP returning FALSE");
            return LW_FALSE;
        }
        /* The candidate point is in the box, so it *might* be inside the tree */
        else
        {
            POINT2D pt2d_outside; /* latlon */
            POINT2D pt2d_inside;
            pt2d_inside.x = in_point->x;
            pt2d_inside.y = in_point->y;
            /* Calculate a definitive outside point */
            gbox_pt_outside(&gbox1, &pt2d_outside);
            POSTGIS_DEBUGF(3, "p2d_inside=POINT(%g %g) p2d_outside=POINT(%g %g)", pt2d_inside.x, pt2d_inside.y, pt2d_outside.x, pt2d_outside.y);
            /* Test the candidate point for strict containment */
            POSTGIS_DEBUG(3, "calling circ_tree_contains_point for PiP test");
            return circ_tree_contains_point(tree1, &pt2d_inside, &pt2d_outside, NULL);
        }
    }
    else
    {
        POSTGIS_DEBUG(3, "tree1 not polygonal, so CircTreePIP returning FALSE");
        return LW_FALSE;
    }
}

/**
* Peak into a #GSERIALIZED datum to find the bounding box. If the
* box is there, copy it out and return it. If not, calculate the box from the
* full object and return the box based on that. If no box is available,
* return #LW_FAILURE, otherwise #LW_SUCCESS.
*/
static int 
gserialized_datum_get_box2df_p(Datum gsdatum, BOX2DF *box2df)
{
	GSERIALIZED *gpart;
	uint8_t flags;
	int result = LW_SUCCESS;

	POSTGIS_DEBUG(4, "entered function");

	/*
	** The most info we need is the 8 bytes of serialized header plus the 
	** of floats necessary to hold the bounding box.
	*/
	gpart = (GSERIALIZED*)PG_DETOAST_DATUM_SLICE(gsdatum, 0, 8 + sizeof(BOX2DF));
	flags = gpart->flags;

	POSTGIS_DEBUGF(4, "got flags %d", gpart->flags);

	/* Do we even have a serialized bounding box? */
	if ( FLAGS_GET_BBOX(flags) )
	{
		/* Yes! Copy it out into the box! */
		POSTGIS_DEBUG(4, "copying box out of serialization");
		memcpy(box2df, gpart->data, sizeof(BOX2DF));
		result = LW_SUCCESS;
	}
	else
	{
		/* No, we need to calculate it from the full object. */
		GBOX gbox;
		GSERIALIZED *g = (GSERIALIZED*)PG_DETOAST_DATUM(gsdatum);
		LWGEOM *lwgeom = lwgeom_from_gserialized(g);
		if ( lwgeom_calculate_gbox(lwgeom, &gbox) == LW_FAILURE )
		{
			POSTGIS_DEBUG(4, "could not calculate bbox, returning failure");
			lwgeom_free(lwgeom);
			return LW_FAILURE;
		}
		lwgeom_free(lwgeom);
		result = box2df_from_gbox_p(&gbox, box2df);
	}
	
	if ( result == LW_SUCCESS )
	{
		POSTGIS_DEBUGF(4, "got box2df %s", box2df_to_string(box2df));
	}

	return result;
}

Datum gserialized_gist_distance_2d(PG_FUNCTION_ARGS)
{
	GISTENTRY *entry = (GISTENTRY*) PG_GETARG_POINTER(0);
	BOX2DF query_box;
	BOX2DF *entry_box;
	StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
	double distance;

	POSTGIS_DEBUG(4, "[GIST] 'distance' function called");

    /* We are using '13' as the gist distance-betweeen-centroids strategy number 
    *  and '14' as the gist distance-between-boxes strategy number */
    if ( strategy != 13 && strategy != 14 ) {
        elog(ERROR, "unrecognized strategy number: %d", strategy);
		PG_RETURN_FLOAT8(MAXFLOAT);
	}

	/* Null box should never make this far. */
	if ( gserialized_datum_get_box2df_p(PG_GETARG_DATUM(1), &query_box) == LW_FAILURE )
	{
		POSTGIS_DEBUG(4, "[GIST] null query_gbox_index!");
		PG_RETURN_FLOAT8(MAXFLOAT);
	}

	/* Get the entry box */
    entry_box = (BOX2DF*)DatumGetPointer(entry->key);
	
	/* Box-style distance test */
	if ( strategy == 14 )
	{
		distance = (double)box2df_distance(entry_box, &query_box);
		PG_RETURN_FLOAT8(distance);
	}

	/* Treat leaf node tests different from internal nodes */
	if (GIST_LEAF(entry))
	{
	    /* Calculate distance to leaves */
		distance = (double)box2df_distance_leaf_centroid(entry_box, &query_box);
	}
	else
	{
	    /* Calculate distance for internal nodes */
		distance = (double)box2df_distance_node_centroid(entry_box, &query_box);
	}

	PG_RETURN_FLOAT8(distance);
}

/* Calculate the volume of the intersection of the boxes. */
static float gidx_inter_volume(GIDX *a, GIDX *b)
{
	int i;
	float result;

	POSTGIS_DEBUG(5,"entered function");

	if ( a == NULL || b == NULL )
	{
		elog(ERROR, "gidx_inter_volume received a null argument");
		return 0.0;
	}

	/* Ensure 'a' has the most dimensions. */
	gidx_dimensionality_check(&a, &b);

	/* Initialize with minimal length of first dimension. */
	result = Min(GIDX_GET_MAX(a,0),GIDX_GET_MAX(b,0)) - Max(GIDX_GET_MIN(a,0),GIDX_GET_MIN(b,0));

	/* If they are disjoint (max < min) then return zero. */
	if ( result < 0.0 ) return 0.0;

	/* Continue for remaining dimensions. */
	for ( i = 1; i < GIDX_NDIMS(b); i++ )
	{
		float width = Min(GIDX_GET_MAX(a,i),GIDX_GET_MAX(b,i)) - Max(GIDX_GET_MIN(a,i),GIDX_GET_MIN(b,i));
		if ( width < 0.0 ) return 0.0;
		/* Multiply by minimal length of remaining dimensions. */
		result *= width;
	}
	POSTGIS_DEBUGF(5, "volume( %s intersection %s ) = %.12g", gidx_to_string(a), gidx_to_string(b), result);
	return result;
}

Datum gserialized_gist_union_2d(PG_FUNCTION_ARGS)
{
	GistEntryVector	*entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
	int *sizep = (int *) PG_GETARG_POINTER(1); /* Size of the return value */
	int	numranges, i;
	BOX2DF *box_cur, *box_union;

	POSTGIS_DEBUG(4, "[GIST] 'union' function called");

	numranges = entryvec->n;

	box_cur = (BOX2DF*) DatumGetPointer(entryvec->vector[0].key);

	box_union = box2df_copy(box_cur);

	for ( i = 1; i < numranges; i++ )
	{
		box_cur = (BOX2DF*) DatumGetPointer(entryvec->vector[i].key);
		box2df_merge(box_union, box_cur);
	}

	*sizep = sizeof(BOX2DF);

	POSTGIS_DEBUGF(4, "[GIST] 'union', numranges(%i), pageunion %s", numranges, box2df_to_string(box_union));

	PG_RETURN_POINTER(box_union);

}

/*
** Equality GIDX test.
**
** Box(A) EQUALS Box(B) IFF (pt(A)LL == pt(B)LL) && (pt(A)UR == pt(B)UR)
*/
static bool gidx_equals(GIDX *a, GIDX *b)
{
	int i;

	POSTGIS_DEBUG(5, "entered function");

	if ( (a == NULL) && (b == NULL) ) return TRUE;
	if ( (a == NULL) || (b == NULL) ) return FALSE;

	/* Ensure 'a' has the most dimensions. */
	gidx_dimensionality_check(&a, &b);

	/* For all shared dimensions min(a) == min(b), max(a) == max(b) */
	for (i = 0; i < GIDX_NDIMS(b); i++)
	{
		if ( GIDX_GET_MIN(a,i) != GIDX_GET_MIN(b,i) )
			return FALSE;
		if ( GIDX_GET_MAX(a,i) != GIDX_GET_MAX(b,i) )
			return FALSE;
	}
	/* For all unshared dimensions min(a) == 0.0, max(a) == 0.0 */
	for (i = GIDX_NDIMS(b); i < GIDX_NDIMS(a); i++)
	{
		if ( GIDX_GET_MIN(a,i) != 0.0 )
			return FALSE;
		if ( GIDX_GET_MAX(a,i) != 0.0 )
			return FALSE;
	}
	return TRUE;
}

/*
** Overlapping GIDX box test.
**
** Box(A) Overlap Box(B) IFF (pt(a)LL < pt(B)UR) && (pt(b)LL < pt(a)UR)
*/
static bool gidx_overlaps(GIDX *a, GIDX *b)
{
	int i;
	int ndims_b;
	POSTGIS_DEBUG(5, "entered function");
	if ( (a == NULL) || (b == NULL) ) return FALSE;

	/* Ensure 'a' has the most dimensions. */
	gidx_dimensionality_check(&a, &b);

	ndims_b = GIDX_NDIMS(b);

	/* compare within the dimensions of (b) */
	for ( i = 0; i < ndims_b; i++ )
	{
		if ( GIDX_GET_MIN(a,i) > GIDX_GET_MAX(b,i) )
			return FALSE;
		if ( GIDX_GET_MIN(b,i) > GIDX_GET_MAX(a,i) )
			return FALSE;
	}

	/* compare to zero those dimensions in (a) absent in (b) */
	for ( i = ndims_b; i < GIDX_NDIMS(a); i++ )
	{
		if ( GIDX_GET_MIN(a,i) > 0.0 )
			return FALSE;
		if ( GIDX_GET_MAX(a,i) < 0.0 )
			return FALSE;
	}
	return TRUE;
}

static float box2df_union_size(const BOX2DF *a, const BOX2DF *b)
{
	float result;

	POSTGIS_DEBUG(5,"entered function");

	if ( a == NULL && b == NULL )
	{
		elog(ERROR, "box2df_union_size received two null arguments");
		return 0.0;
	}
	
	if ( a == NULL )
		return box2df_size(b);

	if ( b == NULL )
		return box2df_size(a);

	result = ((double)Max(a->xmax,b->xmax) - (double)Min(a->xmin,b->xmin)) * 
 	         ((double)Max(a->ymax,b->ymax) - (double)Min(a->ymin,b->ymin));

	POSTGIS_DEBUGF(5, "union size of %s and %s is %.8g", box2df_to_string(a), box2df_to_string(b), result);

	return result;
}

Datum LWGEOM_asText(PG_FUNCTION_ARGS)
{
	GSERIALIZED *geom;
	LWGEOM *lwgeom;
	char *wkt;
	size_t wkt_size;
	text *result;

	POSTGIS_DEBUG(2, "Called.");

	geom = (GSERIALIZED*)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
	lwgeom = lwgeom_from_gserialized(geom);

	/* Write to WKT and free the geometry */
	wkt = lwgeom_to_wkt(lwgeom, WKT_ISO, DBL_DIG, &wkt_size);
	lwgeom_free(lwgeom);
	POSTGIS_DEBUGF(3, "WKT size = %d, WKT length = %d", wkt_size, strlen(wkt));

	/* Write to text and free the WKT */
	result = cstring2text(wkt);
	pfree(wkt);

	/* Return the text */
	PG_FREE_IF_COPY(geom, 0);
	PG_RETURN_TEXT_P(result);
}

Datum LWGEOM_from_text(PG_FUNCTION_ARGS)
{
	text *wkttext = PG_GETARG_TEXT_P(0);
	char *wkt = text2cstring(wkttext);
	LWGEOM_PARSER_RESULT lwg_parser_result;
	GSERIALIZED *geom_result = NULL;
	LWGEOM *lwgeom;

	POSTGIS_DEBUG(2, "LWGEOM_from_text");
	POSTGIS_DEBUGF(3, "wkt: [%s]", wkt);

	if (lwgeom_parse_wkt(&lwg_parser_result, wkt, LW_PARSER_CHECK_ALL) == LW_FAILURE)
		PG_PARSER_ERROR(lwg_parser_result);

	lwgeom = lwg_parser_result.geom;

	if ( lwgeom->srid != SRID_UNKNOWN )
	{
		elog(WARNING, "OGC WKT expected, EWKT provided - use GeomFromEWKT() for this");
	}

	/* read user-requested SRID if any */
	if ( PG_NARGS() > 1 ) 
		lwgeom_set_srid(lwgeom, PG_GETARG_INT32(1));

	geom_result = geometry_serialize(lwgeom);
	lwgeom_parser_result_free(&lwg_parser_result);

	PG_RETURN_POINTER(geom_result);
}

Datum geography_gist_union(PG_FUNCTION_ARGS)
{
	GistEntryVector	*entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
	int *sizep = (int *) PG_GETARG_POINTER(1); /* Size of the return value */
	int	numranges, i;
	GIDX *box_cur, *box_union;

	POSTGIS_DEBUG(4, "[GIST] 'union' function called");

	numranges = entryvec->n;

	box_cur = (GIDX*) DatumGetPointer(entryvec->vector[0].key);

	box_union = gidx_copy(box_cur);

	for ( i = 1; i < numranges; i++ )
	{
		box_cur = (GIDX*) DatumGetPointer(entryvec->vector[i].key);
		gidx_merge(&box_union, box_cur);
	}

	*sizep = VARSIZE(box_union);

	POSTGIS_DEBUGF(4, "[GIST] union called, numranges(%i), pageunion %s", numranges, gidx_to_string(box_union));

	PG_RETURN_POINTER(box_union);

}