after review fix (BUG#4067)

sql/field.cc:
  method getting maximum display length for fields
sql/field.h:
  method getting maximum display length for fields
sql/item.cc:
  code cleanup
  switch replaced with new method
sql/item.h:
  method getting maximum display length for fields

1 files changed, 14 insertions, 0 deletions

diff --git a/sql/field.h b/sql/field.h
index 002a7228164..2b6ef28c184 100644
--- a/sql/field.h
+++ b/sql/field.h
@@ -267,6 +267,8 @@ public:
   void set_warning(const unsigned int level, const unsigned int code);
   virtual field_cast_enum field_cast_type()= 0;
   bool field_cast_compatible(field_cast_enum type);
+  /* maximum possible display length */
+  virtual uint32 max_length()= 0;
   friend bool reopen_table(THD *,struct st_table *,bool);
   friend int cre_myisam(my_string name, register TABLE *form, uint options,
 			ulonglong auto_increment_value);
@@ -336,6 +338,7 @@ public:
   CHARSET_INFO *charset(void) const { return field_charset; }
   void set_charset(CHARSET_INFO *charset) { field_charset=charset; }
   bool binary() const { return field_charset->state & MY_CS_BINSORT ? 1 : 0; }
+  uint32 max_length() { return field_length; }
   friend class create_field;
 };
 
@@ -366,6 +369,7 @@ public:
   void overflow(bool negative);
   bool zero_pack() const { return 0; }
   void sql_type(String &str) const;
+  uint32 max_length() { return field_length; }
   field_cast_enum field_cast_type() { return FIELD_CAST_DECIMAL; }
 };
 
@@ -397,6 +401,7 @@ public:
   void sort_string(char *buff,uint length);
   uint32 pack_length() const { return 1; }
   void sql_type(String &str) const;
+  uint32 max_length() { return 4; }
   field_cast_enum field_cast_type() { return FIELD_CAST_TINY; }
 };
 
@@ -433,6 +438,7 @@ public:
   void sort_string(char *buff,uint length);
   uint32 pack_length() const { return 2; }
   void sql_type(String &str) const;
+  uint32 max_length() { return 6; }
   field_cast_enum field_cast_type() { return FIELD_CAST_SHORT; }
 };
 
@@ -464,6 +470,7 @@ public:
   void sort_string(char *buff,uint length);
   uint32 pack_length() const { return 3; }
   void sql_type(String &str) const;
+  uint32 max_length() { return 8; }
   field_cast_enum field_cast_type() { return FIELD_CAST_MEDIUM; }
 };
 
@@ -500,6 +507,7 @@ public:
   void sort_string(char *buff,uint length);
   uint32 pack_length() const { return 4; }
   void sql_type(String &str) const;
+  uint32 max_length() { return 11; }
   field_cast_enum field_cast_type() { return FIELD_CAST_LONG; }
 };
 
@@ -539,6 +547,7 @@ public:
   uint32 pack_length() const { return 8; }
   void sql_type(String &str) const;
   bool store_for_compare() { return 1; }
+  uint32 max_length() { return 20; }
   field_cast_enum field_cast_type() { return FIELD_CAST_LONGLONG; }
 };
 #endif
@@ -573,6 +582,7 @@ public:
   void sort_string(char *buff,uint length);
   uint32 pack_length() const { return sizeof(float); }
   void sql_type(String &str) const;
+  uint32 max_length() { return 24; }
   field_cast_enum field_cast_type() { return FIELD_CAST_FLOAT; }
 };
 
@@ -607,6 +617,7 @@ public:
   void sort_string(char *buff,uint length);
   uint32 pack_length() const { return sizeof(double); }
   void sql_type(String &str) const;
+  uint32 max_length() { return 53; }
   field_cast_enum field_cast_type() { return FIELD_CAST_DOUBLE; }
 };
 
@@ -637,6 +648,7 @@ public:
   uint32 pack_length() const { return 0; }
   void sql_type(String &str) const;
   uint size_of() const { return sizeof(*this); }
+  uint32 max_length() { return 4; }
   field_cast_enum field_cast_type() { return FIELD_CAST_NULL; }
 };
 
@@ -1034,6 +1046,7 @@ public:
   bool has_charset(void) const
   { return charset() == &my_charset_bin ? FALSE : TRUE; }
   field_cast_enum field_cast_type() { return FIELD_CAST_BLOB; }
+  uint32 max_length();
 };
 
 #ifdef HAVE_SPATIAL
@@ -1062,6 +1075,7 @@ public:
 
   void get_key_image(char *buff,uint length, CHARSET_INFO *cs,imagetype type);
   void set_key_image(char *buff,uint length, CHARSET_INFO *cs);
+  uint32 max_length() { return field_length; }
   field_cast_enum field_cast_type() { return FIELD_CAST_GEOM; }
 };
 #endif /*HAVE_SPATIAL*/