Fix for bug #848901 Assertion `fabs(cur_isc->x-m_cur_intersection->x) +...

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.

mysql-test/r/gis-precise.result

@@ -414,3 +414,6 @@ NULL
 SELECT   ST_DISTANCE (     ST_DIFFERENCE (                                 MULTIPOLYGONFROMTEXT( ' MULTIPOLYGON( ( (3 5, 2 5, 2 4, 3 4, 3 5) ) ) ' ) ,                                 MULTIPOLYGONFROMTEXT( ' MULTIPOLYGON( ( ( 2 2 , 2 8 , 8 8 , 8 2 , 2 2 ) , ( 4 4 , 4 6 , 6 6 , 6 4 , 4 4 ) ) , ( ( 0 0 , 3 8 , 9 4 , 0 0 ) ) ) ' )                         ),                         MULTIPOLYGONFROMTEXT( ' MULTIPOLYGON( ( (3 5, 2 4, 2 5, 3 5) ) , ( (3 5, 2 5, 2 4, 3 4, 3 5) ) , ( ( 0 0 , 8 3 , 9 5 , 0 0 ) ) ) ' ) )  ;
 ST_DISTANCE (     ST_DIFFERENCE (                                 MULTIPOLYGONFROMTEXT( ' MULTIPOLYGON( ( (3 5, 2 5, 2 4, 3 4, 3 5) ) ) ' ) ,                                 MULTIPOLYGONFROMTEXT( ' MULTIPOLYGON( ( ( 2 2 , 2 8 , 8 8 , 8 2 , 2 2 ) , ( 4 4 ,
 NULL
+SELECT ST_NUMGEOMETRIES( ST_SYMDIFFERENCE ( ST_SYMDIFFERENCE ( ST_INTERSECTION ( MULTILINESTRINGFROMTEXT( ' MULTILINESTRING( ( 6 4 , 3 7 , 9 4 , 3 8 ) , ( 2 2 , 2 9 , 1 2 , 9 8 ) ) ' ) , ST_SYMDIFFERENCE ( MULTIPOINTFROMTEXT( ' MULTIPOINT( 6 1 , 3 8 , 3 3 , 0 6 , 7 2 , 3 4 ) ' ) , ST_BUFFER ( ST_UNION ( MULTIPOLYGONFROMTEXT( ' MULTIPOLYGON( ( ( 2 2 , 6 2 , 1 3 , 2 2 , 2 2 ) ) ) ' ) , GEOMETRYFROMTEXT( ' MULTILINESTRING( ( 1 4 , 9 9 , 3 0 , 6 6 ) , ( 3 5 , 1 0 , 5 8 , 6 1 ) , ( 8 9 , 6 1 , 5 1 , 6 2 ) , ( 2 2 , 7 5 , 5 8 , 6 9 , 3 0 ) , ( 8 0 , 8 4 , 6 7 , 5 5 ) ) ' ) ) , NUMPOINTS( EXTERIORRING( POLYGONFROMTEXT( ' POLYGON( ( 0 0 , 2 1 , 8 2 , 0 0 ) ) ' ) ) ) ) ) ) , ST_INTERSECTION ( POLYGONFROMTEXT( ' POLYGON( ( 2 3, 5 7 , 3 7 , 4 1 , 0 5, 2 3 ) ) ' ) , MULTILINESTRINGFROMTEXT( ' MULTILINESTRING( ( 2 3 , 1 4 , 6 4 , 9 1 , 3 4 , 1 8 ) , ( 9 9 , 0 3 , 1 7 , 9 9 ) ) ' ) ) ) , POLYGONFROMTEXT( ' POLYGON( ( 1 3, 7 2 , 1 5 , 3 8 , 5 0, 1 3) ) ' ) ) ) ;
+ST_NUMGEOMETRIES( ST_SYMDIFFERENCE ( ST_SYMDIFFERENCE ( ST_INTERSECTION ( MULTILINESTRINGFROMTEXT( ' MULTILINESTRING( ( 6 4 , 3 7 , 9 4 , 3 8 ) , ( 2 2 , 2 9 , 1 2 , 9 8 ) ) ' ) , ST_SYMDIFFERENCE ( MULTIPOINTFROMTEXT( ' MULTIPOINT( 6 1 , 3 8 , 3 3 , 0 6 
+26

mysql-test/t/gis-precise.test

@@ -279,4 +279,7 @@ SELECT ST_BUFFER (
  ) ;
 SELECT   ST_DISTANCE (     ST_DIFFERENCE (                                 MULTIPOLYGONFROMTEXT( ' MULTIPOLYGON( ( (3 5, 2 5, 2 4, 3 4, 3 5) ) ) ' ) ,                                 MULTIPOLYGONFROMTEXT( ' MULTIPOLYGON( ( ( 2 2 , 2 8 , 8 8 , 8 2 , 2 2 ) , ( 4 4 , 4 6 , 6 6 , 6 4 , 4 4 ) ) , ( ( 0 0 , 3 8 , 9 4 , 0 0 ) ) ) ' )                         ),                         MULTIPOLYGONFROMTEXT( ' MULTIPOLYGON( ( (3 5, 2 4, 2 5, 3 5) ) , ( (3 5, 2 5, 2 4, 3 4, 3 5) ) , ( ( 0 0 , 8 3 , 9 5 , 0 0 ) ) ) ' ) )  ;
 
+#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
+
+SELECT ST_NUMGEOMETRIES( ST_SYMDIFFERENCE ( ST_SYMDIFFERENCE ( ST_INTERSECTION ( MULTILINESTRINGFROMTEXT( ' MULTILINESTRING( ( 6 4 , 3 7 , 9 4 , 3 8 ) , ( 2 2 , 2 9 , 1 2 , 9 8 ) ) ' ) , ST_SYMDIFFERENCE ( MULTIPOINTFROMTEXT( ' MULTIPOINT( 6 1 , 3 8 , 3 3 , 0 6 , 7 2 , 3 4 ) ' ) , ST_BUFFER ( ST_UNION ( MULTIPOLYGONFROMTEXT( ' MULTIPOLYGON( ( ( 2 2 , 6 2 , 1 3 , 2 2 , 2 2 ) ) ) ' ) , GEOMETRYFROMTEXT( ' MULTILINESTRING( ( 1 4 , 9 9 , 3 0 , 6 6 ) , ( 3 5 , 1 0 , 5 8 , 6 1 ) , ( 8 9 , 6 1 , 5 1 , 6 2 ) , ( 2 2 , 7 5 , 5 8 , 6 9 , 3 0 ) , ( 8 0 , 8 4 , 6 7 , 5 5 ) ) ' ) ) , NUMPOINTS( EXTERIORRING( POLYGONFROMTEXT( ' POLYGON( ( 0 0 , 2 1 , 8 2 , 0 0 ) ) ' ) ) ) ) ) ) , ST_INTERSECTION ( POLYGONFROMTEXT( ' POLYGON( ( 2 3, 5 7 , 3 7 , 4 1 , 0 5, 2 3 ) ) ' ) , MULTILINESTRINGFROMTEXT( ' MULTILINESTRING( ( 2 3 , 1 4 , 6 4 , 9 1 , 3 4 , 1 8 ) , ( 9 9 , 0 3 , 1 7 , 9 9 ) ) ' ) ) ) , POLYGONFROMTEXT( ' POLYGON( ( 1 3, 7 2 , 1 5 , 3 8 , 5 0, 1 3) ) ' ) ) ) ;
 

sql/gcalc_slicescan.cc

@@ -950,7 +950,7 @@ int Gcalc_scan_iterator::intersection_scan()
             /* The superfluous intersection should be close to the current. */
             DBUG_ASSERT(fabs(cur_isc->x-m_cur_intersection->x) +
                         fabs(cur_isc->y-m_cur_intersection->y) <
-                        INTERSECTION_ZERO);
+                         0.00000000001);
             isc->next= isc->next->next;
             free_item(cur_isc);
           }