gcc 4.1 linux warning fixes backported from 5.0.

sql/item_cmpfunc.h:
  gcc 4.1 linux warning fixes backported from 5.0
sql/opt_range.cc:
  gcc 4.1 linux warning fixes.
sql/spatial.h:
  gcc 4.1 linux warning fixes backported from 5.0
sql/sql_select.h:
  gcc 4.1 linux warning fixes.
sql/sql_update.cc:
  gcc 4.1 linux warning fixes.

sql/item_cmpfunc.h

@@ -124,6 +124,8 @@ public:
 class Comp_creator
 {
 public:
+  Comp_creator() {}                             /* Remove gcc warning */
+  virtual ~Comp_creator() {}                    /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const = 0;
   virtual const char* symbol(bool invert) const = 0;
   virtual bool eqne_op() const = 0;
@@ -133,6 +135,8 @@ public:
 class Eq_creator :public Comp_creator
 {
 public:
+  Eq_creator() {}                               /* Remove gcc warning */
+  virtual ~Eq_creator() {}                      /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const;
   virtual const char* symbol(bool invert) const { return invert? "<>" : "="; }
   virtual bool eqne_op() const { return 1; }
@@ -142,6 +146,8 @@ public:
 class Ne_creator :public Comp_creator
 {
 public:
+  Ne_creator() {}                               /* Remove gcc warning */
+  virtual ~Ne_creator() {}                      /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const;
   virtual const char* symbol(bool invert) const { return invert? "=" : "<>"; }
   virtual bool eqne_op() const { return 1; }
@@ -151,6 +157,8 @@ public:
 class Gt_creator :public Comp_creator
 {
 public:
+  Gt_creator() {}                               /* Remove gcc warning */
+  virtual ~Gt_creator() {}                      /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const;
   virtual const char* symbol(bool invert) const { return invert? "<=" : ">"; }
   virtual bool eqne_op() const { return 0; }
@@ -160,6 +168,8 @@ public:
 class Lt_creator :public Comp_creator
 {
 public:
+  Lt_creator() {}                               /* Remove gcc warning */
+  virtual ~Lt_creator() {}                      /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const;
   virtual const char* symbol(bool invert) const { return invert? ">=" : "<"; }
   virtual bool eqne_op() const { return 0; }
@@ -169,6 +179,8 @@ public:
 class Ge_creator :public Comp_creator
 {
 public:
+  Ge_creator() {}                               /* Remove gcc warning */
+  virtual ~Ge_creator() {}                      /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const;
   virtual const char* symbol(bool invert) const { return invert? "<" : ">="; }
   virtual bool eqne_op() const { return 0; }
@@ -178,6 +190,8 @@ public:
 class Le_creator :public Comp_creator
 {
 public:
+  Le_creator() {}                               /* Remove gcc warning */
+  virtual ~Le_creator() {}                      /* Remove gcc warning */
   virtual Item_bool_func2* create(Item *a, Item *b) const;
   virtual const char* symbol(bool invert) const { return invert? ">" : "<="; }
   virtual bool eqne_op() const { return 0; }

sql/opt_range.cc

@@ -63,8 +63,8 @@ public:
   SEL_ARG(Field *field, uint8 part, char *min_value, char *max_value,
 	  uint8 min_flag, uint8 max_flag, uint8 maybe_flag);
   SEL_ARG(enum Type type_arg)
-    :elements(1),use_count(1),left(0),next_key_part(0),color(BLACK),
-     type(type_arg),min_flag(0)
+    :min_flag(0),elements(1),use_count(1),left(0),next_key_part(0),
+    color(BLACK), type(type_arg)
   {}
   inline bool is_same(SEL_ARG *arg)
   {

sql/spatial.h

@@ -165,6 +165,8 @@ struct Geometry_buffer;
 class Geometry
 {
 public:
+  Geometry() {}                                 /* remove gcc warning */
+  virtual ~Geometry() {}                        /* remove gcc warning */
   static void *operator new(size_t size, void *buffer)
   {
     return buffer;
@@ -173,6 +175,8 @@ public:
   static void operator delete(void *ptr, void *buffer)
   {}
 
+  static void operator delete(void *buffer) {}  /* remove gcc warning */
+
   enum wkbType
   {
     wkb_point= 1,

sql/sql_select.h

@@ -229,7 +229,7 @@ class JOIN :public Sql_alloc
   }
 
   JOIN(JOIN &join)
-    :fields_list(join.fields_list)
+    :Sql_alloc(), fields_list(join.fields_list)
   {
     init(join.thd, join.fields_list, join.select_options,
          join.result);

sql/sql_update.cc

@@ -1094,7 +1094,7 @@ bool multi_update::send_data(List<Item> &not_used_values)
       memcpy((char*) tmp_table->field[0]->ptr,
 	     (char*) table->file->ref, table->file->ref_length);
       /* Write row, ignoring duplicated updates to a row */
-      if (error= tmp_table->file->write_row(tmp_table->record[0]))
+      if ((error= tmp_table->file->write_row(tmp_table->record[0])))
       {
         if (error != HA_ERR_FOUND_DUPP_KEY &&
             error != HA_ERR_FOUND_DUPP_UNIQUE &&