Fix for bug #26038: X() value of empty NOT NULL POINT is neither NULL nor NOT NULL

Having maybe_null flag unset for geometry/spatial functions leads to
wrong Item_func_isnull::val_int()'s results.
Fix: set maybe_null flag and add is_null() methods.

mysql-test/r/gis.result

@@ -578,7 +578,7 @@ create table t1 select POINT(1,3);
 show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
-  `POINT(1,3)` longblob NOT NULL
+  `POINT(1,3)` longblob
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
 CREATE TABLE `t1` (`object_id` bigint(20) unsigned NOT NULL default '0', `geo`
@@ -677,3 +677,45 @@ load data infile '../../std_data/bad_gis_data.dat' into table t1;
 ERROR 01000: Data truncated; NULL supplied to NOT NULL column 'b' at row 1
 alter table t1 enable keys;
 drop table t1;
+create table t1 (a int, b blob);
+insert into t1 values (1, ''), (2, NULL), (3, '1');
+select * from t1;
+a	b
+1	
+2	NULL
+3	1
+select
+geometryfromtext(b) IS NULL, geometryfromwkb(b) IS NULL, astext(b) IS NULL, 
+aswkb(b) IS NULL, geometrytype(b) IS NULL, centroid(b) IS NULL,
+envelope(b) IS NULL, startpoint(b) IS NULL, endpoint(b) IS NULL,
+exteriorring(b) IS NULL, pointn(b, 1) IS NULL, geometryn(b, 1) IS NULL,
+interiorringn(b, 1) IS NULL, multipoint(b) IS NULL, isempty(b) IS NULL,
+issimple(b) IS NULL, isclosed(b) IS NULL, dimension(b) IS NULL,
+numgeometries(b) IS NULL, numinteriorrings(b) IS NULL, numpoints(b) IS NULL,
+area(b) IS NULL, glength(b) IS NULL, srid(b) IS NULL, x(b) IS NULL, 
+y(b) IS NULL
+from t1;
+geometryfromtext(b) IS NULL	geometryfromwkb(b) IS NULL	astext(b) IS NULL	aswkb(b) IS NULL	geometrytype(b) IS NULL	centroid(b) IS NULL	envelope(b) IS NULL	startpoint(b) IS NULL	endpoint(b) IS NULL	exteriorring(b) IS NULL	pointn(b, 1) IS NULL	geometryn(b, 1) IS NULL	interiorringn(b, 1) IS NULL	multipoint(b) IS NULL	isempty(b) IS NULL	issimple(b) IS NULL	isclosed(b) IS NULL	dimension(b) IS NULL	numgeometries(b) IS NULL	numinteriorrings(b) IS NULL	numpoints(b) IS NULL	area(b) IS NULL	glength(b) IS NULL	srid(b) IS NULL	x(b) IS NULL	y(b) IS NULL
+1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
+select 
+within(b, b) IS NULL, contains(b, b) IS NULL, overlaps(b, b) IS NULL, 
+equals(b, b) IS NULL, disjoint(b, b) IS NULL, touches(b, b) IS NULL, 
+intersects(b, b) IS NULL, crosses(b, b) IS NULL
+from t1;
+within(b, b) IS NULL	contains(b, b) IS NULL	overlaps(b, b) IS NULL	equals(b, b) IS NULL	disjoint(b, b) IS NULL	touches(b, b) IS NULL	intersects(b, b) IS NULL	crosses(b, b) IS NULL
+1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1
+select 
+point(b, b) IS NULL, linestring(b) IS NULL, polygon(b) IS NULL, multipoint(b) IS NULL, 
+multilinestring(b) IS NULL, multipolygon(b) IS NULL, 
+geometrycollection(b) IS NULL
+from t1;
+point(b, b) IS NULL	linestring(b) IS NULL	polygon(b) IS NULL	multipoint(b) IS NULL	multilinestring(b) IS NULL	multipolygon(b) IS NULL	geometrycollection(b) IS NULL
+0	1	1	1	1	1	1
+1	1	1	1	1	1	1
+0	1	1	1	1	1	1
+drop table t1;
+End of 4.1 tests

mysql-test/t/gis.test

@@ -377,4 +377,38 @@ load data infile '../../std_data/bad_gis_data.dat' into table t1;
 alter table t1 enable keys;
 drop table t1;
 
-# End of 4.1 tests
+#
+# Bug #26038: is null and bad data
+#
+
+create table t1 (a int, b blob);
+insert into t1 values (1, ''), (2, NULL), (3, '1');
+select * from t1;
+
+select
+  geometryfromtext(b) IS NULL, geometryfromwkb(b) IS NULL, astext(b) IS NULL, 
+  aswkb(b) IS NULL, geometrytype(b) IS NULL, centroid(b) IS NULL,
+  envelope(b) IS NULL, startpoint(b) IS NULL, endpoint(b) IS NULL,
+  exteriorring(b) IS NULL, pointn(b, 1) IS NULL, geometryn(b, 1) IS NULL,
+  interiorringn(b, 1) IS NULL, multipoint(b) IS NULL, isempty(b) IS NULL,
+  issimple(b) IS NULL, isclosed(b) IS NULL, dimension(b) IS NULL,
+  numgeometries(b) IS NULL, numinteriorrings(b) IS NULL, numpoints(b) IS NULL,
+  area(b) IS NULL, glength(b) IS NULL, srid(b) IS NULL, x(b) IS NULL, 
+  y(b) IS NULL
+from t1;
+
+select 
+  within(b, b) IS NULL, contains(b, b) IS NULL, overlaps(b, b) IS NULL, 
+  equals(b, b) IS NULL, disjoint(b, b) IS NULL, touches(b, b) IS NULL, 
+  intersects(b, b) IS NULL, crosses(b, b) IS NULL
+from t1;
+
+select 
+  point(b, b) IS NULL, linestring(b) IS NULL, polygon(b) IS NULL, multipoint(b) IS NULL, 
+  multilinestring(b) IS NULL, multipolygon(b) IS NULL, 
+  geometrycollection(b) IS NULL
+from t1;
+
+drop table t1;
+
+--echo End of 4.1 tests

sql/item_geofunc.cc

@@ -30,6 +30,7 @@ void Item_geometry_func::fix_length_and_dec()
   collation.set(&my_charset_bin);
   decimals=0;
   max_length=MAX_BLOB_WIDTH;
+  maybe_null= 1;
 }
 
 
@@ -109,6 +110,7 @@ String *Item_func_as_wkt::val_str(String *str)
 void Item_func_as_wkt::fix_length_and_dec()
 {
   max_length=MAX_BLOB_WIDTH;
+  maybe_null= 1;
 }
 
 
@@ -356,7 +358,8 @@ String *Item_func_spatial_collection::val_str(String *str)
   for (i= 0; i < arg_count; ++i)
   {
     String *res= args[i]->val_str(&arg_value);
-    if (args[i]->null_value)
+    uint32 len;
+    if (args[i]->null_value || ((len= res->length()) < WKB_HEADER_SIZE))
       goto err;
 
     if (coll_type == Geometry::wkb_geometrycollection)
@@ -365,13 +368,12 @@ String *Item_func_spatial_collection::val_str(String *str)
 	In the case of GeometryCollection we don't need any checkings
 	for item types, so just copy them into target collection
       */
-      if (str->append(res->ptr(), res->length(), (uint32) 512))
+      if (str->append(res->ptr(), len, (uint32) 512))
         goto err;
     }
     else
     {
       enum Geometry::wkbType wkb_type;
-      uint32 len=res->length();
       const char *data= res->ptr() + 1;
 
       /*
@@ -379,8 +381,6 @@ String *Item_func_spatial_collection::val_str(String *str)
 	are of specific type, let's do this checking now
       */
 
-      if (len < 5)
-        goto err;
       wkb_type= (Geometry::wkbType) uint4korr(data);
       data+= 4;
       len-= 5;
@@ -502,9 +502,13 @@ longlong Item_func_spatial_rel::val_int()
 longlong Item_func_isempty::val_int()
 {
   DBUG_ASSERT(fixed == 1);
-  String tmp; 
-  null_value=0;
-  return args[0]->null_value ? 1 : 0;
+  String tmp;
+  String *swkb= args[0]->val_str(&tmp);
+  Geometry_buffer buffer;
+  
+  null_value= args[0]->null_value ||
+              !(Geometry::construct(&buffer, swkb->ptr(), swkb->length()));
+  return null_value ? 1 : 0;
 }
 
 
@@ -512,10 +516,11 @@ longlong Item_func_issimple::val_int()
 {
   DBUG_ASSERT(fixed == 1);
   String tmp;
-  String *wkb=args[0]->val_str(&tmp);
-
-  if ((null_value= (!wkb || args[0]->null_value)))
-    return 0;
+  String *swkb= args[0]->val_str(&tmp);
+  Geometry_buffer buffer;
+  
+  null_value= args[0]->null_value ||
+              !(Geometry::construct(&buffer, swkb->ptr(), swkb->length()));
   /* TODO: Ramil or Holyfoot, add real IsSimple calculation */
   return 0;
 }

sql/item_geofunc.h

@@ -33,6 +33,7 @@ public:
   Item_geometry_func(List<Item> &list) :Item_str_func(list) {}
   void fix_length_and_dec();
   enum_field_types field_type() const  { return MYSQL_TYPE_GEOMETRY; }
+  bool is_null() { (void) val_int(); return null_value; }
 };
 
 class Item_func_geometry_from_text: public Item_geometry_func
@@ -80,6 +81,7 @@ public:
   void fix_length_and_dec() 
   {
      max_length=20; // "GeometryCollection" is the most long
+     maybe_null= 1;
   };
 };
 
@@ -221,6 +223,8 @@ public:
     }
     }
   void print(String *str) { Item_func::print(str); }
+  void fix_length_and_dec() { maybe_null= 1; }
+  bool is_null() { (void) val_int(); return null_value; }
 };
 
 class Item_func_isempty: public Item_bool_func
@@ -230,6 +234,7 @@ public:
   longlong val_int();
   optimize_type select_optimize() const { return OPTIMIZE_NONE; }
   const char *func_name() const { return "isempty"; }
+  void fix_length_and_dec() { maybe_null= 1; }
 };
 
 class Item_func_issimple: public Item_bool_func
@@ -239,6 +244,7 @@ public:
   longlong val_int();
   optimize_type select_optimize() const { return OPTIMIZE_NONE; }
   const char *func_name() const { return "issimple"; }
+  void fix_length_and_dec() { maybe_null= 1; }
 };
 
 class Item_func_isclosed: public Item_bool_func
@@ -248,6 +254,7 @@ public:
   longlong val_int();
   optimize_type select_optimize() const { return OPTIMIZE_NONE; }
   const char *func_name() const { return "isclosed"; }
+  void fix_length_and_dec() { maybe_null= 1; }
 };
 
 class Item_func_dimension: public Item_int_func
@@ -257,7 +264,7 @@ public:
   Item_func_dimension(Item *a): Item_int_func(a) {}
   longlong val_int();
   const char *func_name() const { return "dimension"; }
-  void fix_length_and_dec() { max_length=10; }
+  void fix_length_and_dec() { max_length= 10; maybe_null= 1; }
 };
 
 class Item_func_x: public Item_real_func
@@ -267,6 +274,11 @@ public:
   Item_func_x(Item *a): Item_real_func(a) {}
   double val();
   const char *func_name() const { return "x"; }
+  void fix_length_and_dec() 
+  { 
+    Item_real_func::fix_length_and_dec();
+    maybe_null= 1; 
+  }
 };
 
 
@@ -277,6 +289,11 @@ public:
   Item_func_y(Item *a): Item_real_func(a) {}
   double val();
   const char *func_name() const { return "y"; }
+  void fix_length_and_dec() 
+  { 
+    Item_real_func::fix_length_and_dec();
+    maybe_null= 1; 
+  }
 };
 
 
@@ -287,7 +304,7 @@ public:
   Item_func_numgeometries(Item *a): Item_int_func(a) {}
   longlong val_int();
   const char *func_name() const { return "numgeometries"; }
-  void fix_length_and_dec() { max_length=10; }
+  void fix_length_and_dec() { max_length= 10; maybe_null= 1; }
 };
 
 
@@ -298,7 +315,7 @@ public:
   Item_func_numinteriorring(Item *a): Item_int_func(a) {}
   longlong val_int();
   const char *func_name() const { return "numinteriorrings"; }
-  void fix_length_and_dec() { max_length=10; }
+  void fix_length_and_dec() { max_length= 10; maybe_null= 1; }
 };
 
 
@@ -309,7 +326,7 @@ public:
   Item_func_numpoints(Item *a): Item_int_func(a) {}
   longlong val_int();
   const char *func_name() const { return "numpoints"; }
-  void fix_length_and_dec() { max_length=10; }
+  void fix_length_and_dec() { max_length= 10; maybe_null= 1; }
 };
 
 
@@ -320,6 +337,11 @@ public:
   Item_func_area(Item *a): Item_real_func(a) {}
   double val();
   const char *func_name() const { return "area"; }
+  void fix_length_and_dec() 
+  { 
+    Item_real_func::fix_length_and_dec();
+    maybe_null= 1; 
+  }
 };
 
 
@@ -330,6 +352,11 @@ public:
   Item_func_glength(Item *a): Item_real_func(a) {}
   double val();
   const char *func_name() const { return "glength"; }
+  void fix_length_and_dec() 
+  { 
+    Item_real_func::fix_length_and_dec();
+    maybe_null= 1; 
+  }
 };
 
 
@@ -340,7 +367,7 @@ public:
   Item_func_srid(Item *a): Item_int_func(a) {}
   longlong val_int();
   const char *func_name() const { return "srid"; }
-  void fix_length_and_dec() { max_length= 10; }
+  void fix_length_and_dec() { max_length= 10; maybe_null= 1; }
 };
 
 #define GEOM_NEW(obj_constructor) new obj_constructor

sql/spatial.cc

@@ -210,23 +210,24 @@ static uint32 wkb_get_uint(const char *ptr, Geometry::wkbByteOrder bo)
 }
 
 
-int Geometry::create_from_wkb(Geometry_buffer *buffer,
-                              const char *wkb, uint32 len, String *res)
+Geometry *Geometry::create_from_wkb(Geometry_buffer *buffer,
+                                    const char *wkb, uint32 len, String *res)
 {
   uint32 geom_type;
   Geometry *geom;
 
   if (len < WKB_HEADER_SIZE)
-    return 1;
+    return NULL;
   geom_type= wkb_get_uint(wkb+1, (wkbByteOrder)wkb[0]);
   if (!(geom= create_by_typeid(buffer, (int) geom_type)) ||
       res->reserve(WKB_HEADER_SIZE, 512))
-    return 1;
+    return NULL;
 
   res->q_append((char) wkb_ndr);
   res->q_append(geom_type);
-  return geom->init_from_wkb(wkb+WKB_HEADER_SIZE, len - WKB_HEADER_SIZE,
-                             (wkbByteOrder) wkb[0], res);
+
+  return geom->init_from_wkb(wkb + WKB_HEADER_SIZE, len - WKB_HEADER_SIZE,
+                             (wkbByteOrder) wkb[0], res) ? geom : NULL;
 }
 
 

sql/spatial.h

@@ -244,8 +244,8 @@ public:
   static Geometry *create_from_wkt(Geometry_buffer *buffer,
 				   Gis_read_stream *trs, String *wkt,
 				   bool init_stream=1);
-  static int create_from_wkb(Geometry_buffer *buffer,
-                             const char *wkb, uint32 len, String *res);
+  static Geometry *create_from_wkb(Geometry_buffer *buffer, const char *wkb, 
+                                   uint32 len, String *res);
   int as_wkt(String *wkt, const char **end)
   {
     uint32 len= get_class_info()->m_name.length;