Fix warnings and compilation failures (Windows).

sql/field.cc:
  Fix warning.
sql/item_func.cc:
  Fix Windows compilation failure.
sql/opt_range.cc:
  Fix warnings and errors (Windows)
sql/sp_pcontext.h:
  Fix warning (Windows).
sql/table.h:
  Fix warning (Windows).

sql/field.cc

@@ -1785,7 +1785,6 @@ int Field_long::store(const char *from,uint len,CHARSET_INFO *cs)
   longlong tmp;
   long store_tmp;
   int error;
-  bool warning_given= 0;
   char *end;
   
   tmp= cs->cset->scan(cs, from, from+len, MY_SEQ_SPACES);
@@ -2075,7 +2074,6 @@ int Field_longlong::store(const char *from,uint len,CHARSET_INFO *cs)
   longlong tmp;
   int error= 0;
   char *end;
-  bool warning_given;
 
   tmp= cs->cset->scan(cs, from, from+len, MY_SEQ_SPACES);
   len-= (uint)tmp;

sql/item_func.cc

@@ -174,7 +174,7 @@ bool Item_func::agg_arg_charsets(DTCollation &coll,
   for (arg= args, last= args + nargs; arg < last; arg++)
   {
     Item* conv;
-    uint dummy_offset;
+    uint32 dummy_offset;
     if (!String::needs_conversion(0, coll.collation,
                                   (*arg)->collation.collation,
                                   &dummy_offset))

sql/opt_range.cc

@@ -5533,7 +5533,6 @@ QUICK_RANGE_SELECT *get_quick_select_for_ref(THD *thd, TABLE *table,
       goto err;
   }
 
-ok:
   thd->mem_root= old_root;
   return quick;
 
@@ -8067,7 +8066,8 @@ int QUICK_GROUP_MIN_MAX_SELECT::next_min_in_range()
       boundary of cur_range, there is no need to check this range.
     */
     if (range_idx != 0 && !(cur_range->flag & NO_MAX_RANGE) &&
-        (key_cmp(min_max_arg_part, cur_range->max_key, min_max_arg_len) == 1))
+        (key_cmp(min_max_arg_part, (byte*) cur_range->max_key,
+                 min_max_arg_len) == 1))
       continue;
 
     if (cur_range->flag & NO_MIN_RANGE)
@@ -8193,7 +8193,8 @@ int QUICK_GROUP_MIN_MAX_SELECT::next_max_in_range()
     */
     if (range_idx != min_max_ranges.elements &&
         !(cur_range->flag & NO_MIN_RANGE) &&
-        (key_cmp(min_max_arg_part, cur_range->min_key, min_max_arg_len) == -1))
+        (key_cmp(min_max_arg_part, (byte*) cur_range->min_key,
+                 min_max_arg_len) == -1))
       continue;
 
     if (cur_range->flag & NO_MAX_RANGE)

sql/sp_pcontext.h

@@ -50,7 +50,7 @@ typedef struct sp_label
   char *name;
   uint ip;			// Instruction index
   int type;			// begin/iter or ref/free 
-  struct sp_pcontext *ctx;	// The label's context
+  sp_pcontext *ctx;             // The label's context
 } sp_label_t;
 
 typedef struct sp_cond_type

sql/table.h

@@ -274,7 +274,7 @@ typedef struct st_schema_table
 #define VIEW_CHECK_SKIP       2
 
 struct st_lex;
-struct select_union;
+class select_union;
 
 typedef struct st_table_list
 {