Forward calculations introduced.

per-file comments:
  sql/gcalc_slicescan.cc
  sql/gcalc_slicescan.h
  sql/gcalc_tools.cc
  sql/gcalc_tools.h
  sql/item_geofunc.cc

Coordinate size limitation removed.

per-file comments:
  mysql-test/r/gis-precise.result
        test result updated.
  sql/gcalc_slicescan.cc
        Check coordinate extent to pick better precidion in the ::set_double()
  sql/gcalc_slicescan.h
        free_list() can lead to valgrind warnig. Fixed
  sql/gcalc_tools.cc
        free_list() call changed.

GCALC_xxx macros fixed for the GCALC_DBUG_OFF case.

per-file comments:
  sql/gcalc_slicescan.h
GIS code cleanup.

GCALC_DBUG_OFF and related infrastructure defined so we can enable/disable debugging conveniently.

per-file comments:
  sql/gcalc_slicescan.cc
GIS library code cleanup.
  sql/gcalc_slicescan.h
GIS library code cleanup.
  sql/gcalc_tools.cc
GIS library code cleanup.
  sql/gcalc_tools.h
GIS library code cleanup.

        Line autointersection point was treated as if it doesn't belong to the line.
        It's in some way logical, but seems to confuse people. Fixed.

per_file_comments:
  mysql-test/r/gis-precise.result
bug 857087 Wrong result with ST_INTERSECTS and LINESTRINGs
        test result updated.
  mysql-test/t/gis-precise.test
bug 857087 Wrong result with ST_INTERSECTS and LINESTRINGs
        test case added.
  sql/gcalc_tools.cc
bug 857087 Wrong result with ST_INTERSECTS and LINESTRINGs
        Point of line autointersection handled as it belongs to the line.
  sql/gcalc_tools.h
bug 857087 Wrong result with ST_INTERSECTS and LINESTRINGs
        Gcalc_function::set_i_state() added

        actually only testcase added as the bug was fixed already.

modified:
  mysql-test/r/gis-precise.result
bug #857050 ST_WITHIN returns wrong result with MULTIPOINT and POLYGON
        test result updated.
  mysql-test/t/gis-precise.test
bug #857050 ST_WITHIN returns wrong result with MULTIPOINT and POLYGON
        test case added.
  sql/gcalc_tools.cc
        superfluous variable removed.

        The 'single point' event was forgotten in the relation's calculation

per-file comments:
  mysql-test/r/gis-precise.result
fix for bug 857051 ST_EQUALS returns TRUE on two nonidentical MULTIPOINTs
        test result updated.
  mysql-test/t/gis-precise.test
fix for bug 857051 ST_EQUALS returns TRUE on two nonidentical MULTIPOINTs
        test case added.
  sql/gcalc_tools.cc
fix for bug 857051 ST_EQUALS returns TRUE on two nonidentical MULTIPOINTs
        scev_single_point is properly handled.

        return GEOMETRYCOLLECTION EMPTY, not NULL for the query

per-file comments:
  mysql-test/r/gis.result
fix for 857050 ST_WITHIN returns wrong result with MULTIPOINT and POLYGON
        test result updated.
  sql/spatial.cc
fix for 857050 ST_WITHIN returns wrong result with MULTIPOINT and POLYGON
        return of the Geometry::envelope() changed for the empty geometry.

855485  ST_CROSSES returns different result than PostGIS for overlapping polygons
855487  ST_WITHIN returns wrong result for partially overlapping polygons
855492  ST_WITHIN returns TRUE on point on the edge of a polygon
855497  ST_ENVELOPE of GEOMETRYCOLLECTION EMPTY returns NULL and not GEOMETRYCOLLECTION EMPTY
855503  ST_EQUALS reports TRUE between a POLYGON and a MULTILINESTRING
855505  ST_TOUCHES reports TRUE for intersecting polygon and linestring

        Changed the way weird functions like Crosses or Touches treated.
        Added BORDER handling to the Gcalc_function.

per-file comments:
  mysql-test/r/gis-precise.result
        GIS bugs fixed.
        test result updated.
  mysql-test/t/gis-precise.test
        GIS bugs fixed.
        test cases added.
  sql/gcalc_slicescan.h
        GIS bugs fixed.
  sql/gcalc_tools.cc
        GIS bugs fixed.
  sql/gcalc_tools.h
        GIS bugs fixed.
  sql/item_create.cc
        GIS bugs fixed.
  sql/item_geofunc.cc
        GIS bugs fixed.
  sql/item_geofunc.h
        GIS bugs fixed.
  sql/spatial.cc
        GIS bugs fixed.

per-file comments:
  mysql-test/r/gis.result
bug 855336      ST_LENGTH does not work on GEOMETRYCOLLECTIONs fixed.
        test result updated.
  mysql-test/t/gis.test
bug 855336      ST_LENGTH does not work on GEOMETRYCOLLECTIONs fixed.
        test case added.
  sql/item_geofunc.cc
bug 855336      ST_LENGTH does not work on GEOMETRYCOLLECTIONs fixed.
        geom_length() call fixed.
  sql/spatial.cc
bug 855336      ST_LENGTH does not work on GEOMETRYCOLLECTIONs fixed.
        Geometry_collection::geom_length implemented.
  sql/spatial.h
bug 855336      ST_LENGTH does not work on GEOMETRYCOLLECTIONs fixed.
        Geometry_collection::geom_length declaration added.

fix for bug 848926 GIS functions return "GEOMETRYCOLLECTION()" instead of "GEOMETRYCOLLECTION EMPTY"

per-file comments:
  mysql-test/r/gis.result
fix for bug 848926 GIS functions return "GEOMETRYCOLLECTION()" instead of "GEOMETRYCOLLECTION EMPTY"
        test result updated.
  mysql-test/t/gis.test
fix for bug 848926 GIS functions return "GEOMETRYCOLLECTION()" instead of "GEOMETRYCOLLECTION EMPTY"
        test case added.
  sql/gstream.cc
fix for bug 848926 GIS functions return "GEOMETRYCOLLECTION()" instead of "GEOMETRYCOLLECTION EMPTY"
        lookup_next_word() implemented.
  sql/gstream.h
fix for bug 848926 GIS functions return "GEOMETRYCOLLECTION()" instead of "GEOMETRYCOLLECTION EMPTY"
        lookup_next_word() added.
  sql/spatial.cc
fix for bug 848926 GIS functions return "GEOMETRYCOLLECTION()" instead of "GEOMETRYCOLLECTION EMPTY"
        name changed for the empty geometry.
  sql/spatial.h
fix for bug 848926 GIS functions return "GEOMETRYCOLLECTION()" instead of "GEOMETRYCOLLECTION EMPTY"
        declarations modified.

        855253 Compiler error: gcalc_slicescan.cc:2036: error: suggest parentheses around comparison in operand of .|. in maria-5.3-gis
        850775 ST_AREA does not work on GEOMETRYCOLLECTIONs in maria-5.3-gis

per-file comments:
  mysql-test/r/gis.result
        test result updated.
  mysql-test/t/gis.test
        test case added for 850775.
  sql/gcalc_slicescan.cc
        compiler error fixed.
  sql/spatial.cc
        ST_AREA implementation for GEOMETRY_COLLECTION, POINT and LINESTRING.
  sql/spatial.h
        area() declarations added.

        849789  Second assertion `m_poly_borders->next' failed in Gcalc_operation_reducer::count_slice in maria-5.3-gis
        849791  Fourth assertion `n > 0 && n < SINUSES_CALCULATED*2+1' in get_n_sincos
        849789  Second assertion `m_poly_borders->next' failed in Gcalc_operation_reducer::count_slice in maria-5.3-gis
        848901   Assertion `fabs(cur_isc->x-m_cur_intersection->x) + fabs(cur_isc->y-m_cur_intersection->y) < 0.000000000001' failed in Gcalc_scan_iterator::intersection_scan() in maria-5.3-gis
        
per-file comments:
  mysql-test/r/gis-precise.result
        test result updated.
  mysql-test/r/gis.result
        test result updated.
  sql/gcalc_slicescan.cc
        bugfixes.
  sql/gcalc_slicescan.h
        bugfixes.
  sql/gcalc_tools.cc
        bugfixes.
  sql/gcalc_tools.h
        bugfixes.
  sql/item_geofunc.cc
        bugfixes.
  sql/spatial.cc
        bugfixes.

        Coordinates were mistakenly reversed for MULTIPOINT.

per-file comments:
  mysql-test/r/gis-precise.result
Fix for bug 848939 Wrong result with ST_INTERSECTION between linestrings and a polygon in 5.3-gis
        test result updated.
  mysql-test/t/gis-precise.test
Fix for bug 848939 Wrong result with ST_INTERSECTION between linestrings and a polygon in 5.3-gis
        test case added.
  sql/gcalc_tools.cc
Fix for bug 848939 Wrong result with ST_INTERSECTION between linestrings and a polygon in 5.3-gis
        coordinates set in the proper order.

Fix for bug #848901 Assertion `fabs(cur_isc->x-m_cur_intersection->x) + fabs(cur_isc->y-m_cur_intersection->y) < 0.000000000001' failed in Gcalc_scan_iterator::intersection_scan() in maria-5.3-gis

        That assertion's check was too tight. Released it a bit.

per-file comments:
  mysql-test/r/gis-precise.result
        Fix for bug #848901
        test result updated.
  mysql-test/t/gis-precise.test
        Fix for bug #848901
        test case added.
  sql/gcalc_slicescan.cc
        Fix for bug #848901
        The DBUG_ASSERT check is too tight here.

  #841622 Assertion `t->rp->type == Gcalc_function::shape_line' failed in Gcalc_operation_reducer::end_line in maria-5.3-gi
  #841625 Assertion `m_poly_borders->next' failed in Gcalc_operation_reducer::count_slice in maria-5.3-gis
  #841638 Assertion `!m_prev || m_prev->x != x || m_prev->y != y' failed in Gcalc_shape_transporter::int_add_point in maria-5.3-gis
  #841662 Third assertion `n > 0 && n < SINUSES_CALCULATED*2+1' in get_n_sincos
  #841745 Assertion `!sp0->is_bottom()' failed in Gcalc_scan_iterator::find_intersections in maria-5.3-gis

  They mostly was caused by inprecision of double arithmetic.
  Fixed by changes in how to handle multiple intersections to keep their order right.

  Also ST_DISTANCE(GEOM, EMPTY_GEOM) was defined as NULL.


per-file comments:
  mysql-test/r/gis-precise.result
   GIS bugfixes.
        test result updated.
  mysql-test/t/gis-precise.test
   GIS bugfixes.
        test cases added.
  sql/gcalc_slicescan.cc
   GIS bugfixes.
        If intersections are close, add order checks to cope with the
        double calcualtions imprecision.
  sql/gcalc_slicescan.h
   GIS bugfixes.
        n_row parameter added to intersection to check their order.
  sql/item_geofunc.cc
   GIS bugfixes.
        ST_DISTANCE(GEOM, EMPTY_GEOM) returns NULL.

        When edges of a polygon coicide, it can form an pike, that is turned into a line after an operation.
        In this case a former polygon point can be an end of a single line, and that case wasn't properly handled.


per-file comments:
  mysql-test/r/gis-precise.result
bug 839327 Crash in Gcalc_operation_reducer::end_couple with ST_UNION and MULTIPOLYGONs in 5.3-gis.
        test result updated.

  mysql-test/t/gis-precise.test
bug 839327 Crash in Gcalc_operation_reducer::end_couple with ST_UNION and MULTIPOLYGONs in 5.3-gis.
        test case added.

  sql/gcalc_tools.cc
bug 839327 Crash in Gcalc_operation_reducer::end_couple with ST_UNION and MULTIPOLYGONs in 5.3-gis.
        in the scev_two_ends case check if we have single line ending on a polygon node.

bug 839318 Crash in Gcalc_scan_iterator::point::get_shape with ST_DISTANCE and MULTILINESTRING in maria-5.3-gis.
        wrong variable was used as a result of inattentive copypaste.

per-file comments:
  mysql-test/r/gis-precise.result
bug 839318 Crash in Gcalc_scan_iterator::point::get_shape with ST_DISTANCE and MULTILINESTRING in maria-5.3-gis.
     test result updated.

  mysql-test/t/gis-precise.test
bug 839318 Crash in Gcalc_scan_iterator::point::get_shape with ST_DISTANCE and MULTILINESTRING in maria-5.3-gis.
     test case added.

  sql/item_geofunc.cc
bug 839318 Crash in Gcalc_scan_iterator::point::get_shape with ST_DISTANCE and MULTILINESTRING in maria-5.3-gis.
     use 'ev' variable instead of the 'evpos'.

    Line loops weren't recognized when collect results.
    Fixed by checking if we got the same beginning point of the line.

per-file comments:
  mysql-test/r/gis-precise.result
bug 839341 100% CPU usage with ST_UNION in maria-5.3-gis.
      test result updated.
  mysql-test/t/gis-precise.test
bug 839341 100% CPU usage with ST_UNION in maria-5.3-gis.
      test case added.
  sql/gcalc_tools.cc
bug 839341 100% CPU usage with ST_UNION in maria-5.3-gis.
      check if we get the beginning node of the linestring, then cut the loop.

    We didn't implement an empty geometry. And returning NULL instead of it is not
    quite correct. So here is the implementation of the empty value as GEOMETRYCOLLECTION().

per-file comments:
  mysql-test/r/gis-precise.result
bug 801466 ST_INTERSECTION() returns invalid value on empty intersection in maria-5.3-gis.
    test result updated.

  mysql-test/r/gis.result
bug 801466 ST_INTERSECTION() returns invalid value on empty intersection in maria-5.3-gis.
    test result updated.

  mysql-test/t/gis-precise.test
bug 801466 ST_INTERSECTION() returns invalid value on empty intersection in maria-5.3-gis.
    test case added.

  mysql-test/t/gis.test
bug 801466 ST_INTERSECTION() returns invalid value on empty intersection in maria-5.3-gis.
    test case added.

  sql/field.cc
bug 801466 ST_INTERSECTION() returns invalid value on empty intersection in maria-5.3-gis.
    store GEOMETRYCOLLECTION() properly.

  sql/gcalc_tools.cc
bug 801466 ST_INTERSECTION() returns invalid value on empty intersection in maria-5.3-gis.
    create the GEOMETRYCOLLECTION() for the empty result.

  sql/gstream.h
bug 801466 ST_INTERSECTION() returns invalid value on empty intersection in maria-5.3-gis.
    next_symbol() added.

  sql/spatial.cc
bug 801466 ST_INTERSECTION() returns invalid value on empty intersection in maria-5.3-gis.
    code modified to handle 0 geometries in the GEOMETRYCOLLECTION properly.

tests added.

per-file comments:
  mysql-test/r/gis-precise.result
bugs #801560 and #802194
        test result updated.

  mysql-test/t/gis-precise.test
bugs #801560 and #802194
        test case added.

        Second smaller hole in the polygon got link to the bigger one as it's the
        outer ring. Fixed by specifying the outer ring explicitly.


per-file comments:
  mysql-test/r/gis-precise.result
Fix for bug #804266 Memory corruption/valgrind warning/crash in move_hole() with ST_UNION.
        test result updated.

  mysql-test/t/gis-precise.test
Fix for bug #804266 Memory corruption/valgrind warning/crash in move_hole() with ST_UNION.
        test case added.

  sql/gcalc_tools.cc
Fix for bug #804266 Memory corruption/valgrind warning/crash in move_hole() with ST_UNION.
        specify the outer ring explicitly in the get_polygon_result parameter.

  sql/gcalc_tools.h
Fix for bug #804266 Memory corruption/valgrind warning/crash in move_hole() with ST_UNION.
        add the outer ring as a parameter to the get_polygon_result.

        We cannot cut a line from a polygon. So if the polygon fits the condition, and
        the intersection of a line and the polygon doesn't, we just skip the line.
        That rule wasn't applied if the line start was inside the polygon, which leaded
        to the assertion.

per-file comments:
  mysql-test/r/gis-precise.result
Fix for bug #801217 Assertion `t1->result_range' in Gcalc_operation_reducer::end_couple.
        test result updated.
  mysql-test/t/gis-precise.test
Fix for bug #801217 Assertion `t1->result_range' in Gcalc_operation_reducer::end_couple.
        test case added.
  sql/gcalc_tools.cc
Fix for bug #801217 Assertion `t1->result_range' in Gcalc_operation_reducer::end_couple.
        Don't mark the line as a border if it's inside a polygon that fits the result condition.

        A polygon has no right to have holes that are actually points.
        So just skip them when we collect the result of an operation.

per-file comments:
  mysql-test/r/gis-precise.result
Fix for bug #804259 Second assertion in Gis_geometry_collection::init_from_opresult.
        test result updated.
  mysql-test/t/gis-precise.test
Fix for bug #804259 Second assertion in Gis_geometry_collection::init_from_opresult.
        test case added.
  sql/gcalc_tools.cc
Fix for bug #804259 Second assertion in Gis_geometry_collection::init_from_opresult.
        Skip the point in the result if it's the hole inside a polygon.

Fix for bug #805860 Second assertion Assertion `n > 0 && n < SINUSES_CALCULATED*2+1' in get_n_sincos.
        Just typo-style mistake. Should be '||' instead of '&&'.

per-file comments:
  mysql-test/r/gis-precise.result
Fix for bug #805860 Second assertion Assertion `n > 0 && n < SINUSES_CALCULATED*2+1' in get_n_sincos.
        test result updated.
  mysql-test/t/gis-precise.test
Fix for bug #805860 Second assertion Assertion `n > 0 && n < SINUSES_CALCULATED*2+1' in get_n_sincos.
        test case added.
  sql/item_geofunc.cc
Fix for bug #805860 Second assertion Assertion `n > 0 && n < SINUSES_CALCULATED*2+1' in get_n_sincos.
        condition fixed.

        There were actually two bugs. One was when the line that intersects itself
        the intersection point treated as it doesn't belong to the line.
        Second when edges partly coincide, wrong result produced when we try to find their
        intersection.


per-file comments:
  mysql-test/r/gis-precise.result
Fix for bug #804324 Assertion 0 in Gcalc_scan_iterator::pop_suitable_intersection
        test result updated.

  mysql-test/t/gis-precise.test
Fix for bug #804324 Assertion 0 in Gcalc_scan_iterator::pop_suitable_intersection
        test case added.

  sql/gcalc_slicescan.cc
Fix for bug #804324 Assertion 0 in Gcalc_scan_iterator::pop_suitable_intersection
        skip the intersection if it just line that intersects itself.

  sql/gcalc_tools.cc
Fix for bug #804324 Assertion 0 in Gcalc_scan_iterator::pop_suitable_intersection
        if edges coincide, just pick the first coinciding poing as an intersection.

        That crash happened with the complicated topology of the result.
        If we found a hole in a polygon whose outside border was already
        found, we need to paste the hole right after it and respectively
        shift polygons after it. Also we need to update poly_position fields
        in these polygons. That last thing wasn't properly done that led to the
        crash.
        To fix that we keep the list of the found polygons and update the
        poly_positions that are bigger or equal to where we placed the next hole.


per-file comments:
  mysql-test/r/gis-precise.result
bug #804305 Crash in wkb_get_double with ST_INTERSECTION.
        test result updated.
  mysql-test/t/gis-precise.test
bug #804305 Crash in wkb_get_double with ST_INTERSECTION.
        test result added.
  sql/gcalc_tools.cc
bug #804305 Crash in wkb_get_double with ST_INTERSECTION.
        keep the list of the found polygons and update their poly_position fields respectively.
  sql/gcalc_tools.h
bug #804305 Crash in wkb_get_double with ST_INTERSECTION.
        Gcalc_result_receiver::move_hole interface changed.

        The ::val_str() method has to return NULL if it calculated
        the null_value, not just set the related flag.

per-file comments:
  mysql-test/r/gis-precise.result
fix for bug #801212 Assertion with ST_INTERSECTION on NULL values
        test result updated.
  mysql-test/t/gis-precise.test
fix for bug #801212 Assertion with ST_INTERSECTION on NULL values
        test case added.
  sql/item_geofunc.cc
fix for bug #801212 Assertion with ST_INTERSECTION on NULL values
        return NULL from the val_str if we get the null_value.

        Collections were treated mistakenly, so the counter for the final UNION operation
        received the wrong value.
        As a fix we implement Item_func_buffer::Transporter::start_collection() method,
        where we set the proper operation and the operand counter.
        start_poly() and start_line() were also modified to function correctly for the 
        polygon as a part of a collection.

per-file comments:
  mysql-test/r/gis-precise.result
bug #801199 Infinite recursion in Gcalc_function::count_internal with ST_BUFFER over MULTIPOINT
        test result updated.

  mysql-test/t/gis-precise.test
bug #801199 Infinite recursion in Gcalc_function::count_internal with ST_BUFFER over MULTIPOINT
        test case added.

  sql/item_geofunc.cc
bug #801199 Infinite recursion in Gcalc_function::count_internal with ST_BUFFER over MULTIPOINT
        start_collection() implemented.

  sql/item_geofunc.h
bug #801199 Infinite recursion in Gcalc_function::count_internal with ST_BUFFER over MULTIPOINT
        Item_func_buffer::Transporter::start_collection() defined.

        Internal caclucations can't handle zero distance properly.
        As the ST_BUFFER(geom, 0) is in fact NOOP, we'll just return the
        'geom' as the result here.

per-file comments:
  mysql-test/r/gis-precise.result
fix for bug #201189 ST_BUFFER asserts if radius = 0.
        test result updated.

  mysql-test/t/gis-precise.test
fix for bug #201189 ST_BUFFER asserts if radius = 0.
        test case added.

  sql/item_geofunc.cc
fix for bug #201189 ST_BUFFER asserts if radius = 0.
        return the first argument as the result of the ST_BUFFER, if
        the distance is 0 there.

fix for bug #801243 Assertion `(0)' failed in Gis_geometry_collection::init_from_opresult on ST_UNION 
        If the result contains a polygon with a hole, consequitive shapes weren't calculated
        properly, as the hole appeared as shape in the result, but actually it's a single shape
        with the surrounding polygon. It's more natural to use the size of the result as
        a border instead of the number of resulting shapes.

per-file comments:
  mysql-test/r/gis-precise.result
fix for bug #801243 Assertion `(0)' failed in Gis_geometry_collection::init_from_opresult on ST_UNION 
        test result updated.
  mysql-test/t/gis-precise.test
fix for bug #801243 Assertion `(0)' failed in Gis_geometry_collection::init_from_opresult on ST_UNION 
        test case added.
  sql/spatial.cc
fix for bug #801243 Assertion `(0)' failed in Gis_geometry_collection::init_from_opresult on ST_UNION 
        check the data lenght instead of number of shapes.
  sql/spatial.h
fix for bug #801243 Assertion `(0)' failed in Gis_geometry_collection::init_from_opresult on ST_UNION 
        check the data lenght instead of number of shapes.

merging.