Fix for Bug# 4200 "Parse error on LIKE ESCAPE with parameter binding"

Now ESCAPE in LIKE will accept not only string literal but constant 
delimited expression.


mysql-test/r/func_like.result:
  Added test for bug# 4200 "Parse error on LIKE ESCAPE with parameter binding"
mysql-test/t/func_like.test:
  Added test for bug# 4200 "Parse error on LIKE ESCAPE with parameter binding"
sql/item_cmpfunc.cc:
  Added support for accepting of constant delimited expression as ESCAPE argument to
  Item_func_like.
sql/item_cmpfunc.h:
  Now ESCAPE clause in LIKE will accept not only string literal but constant delimited 
  expression. Thus added member to Item_func_like for storing Item corresponding to this
  expression and changed third argument of cons to be Item* instead of char*.
sql/sql_help.cc:
  Item_func_like now accepts Item* as third argument.
sql/sql_yacc.yy:
  Now ESCAPE clause of LIKE accepts not only string literal but constant delimited expression
  (the most important case is prepared statement parameter of course).

1 files changed, 4 insertions, 2 deletions

diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index ef80c060c03..4a7e7e06f10 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -841,12 +841,14 @@ class Item_func_like :public Item_bool_func2
   bool turboBM_matches(const char* text, int text_len) const;
   enum { alphabet_size = 256 };
 
+  Item *escape_item;
+
 public:
   char escape;
 
-  Item_func_like(Item *a,Item *b, char* escape_arg)
+  Item_func_like(Item *a,Item *b, Item *escape_arg)
     :Item_bool_func2(a,b), canDoTurboBM(false), pattern(0), pattern_len(0), 
-     bmGs(0), bmBc(0), escape(*escape_arg) {}
+     bmGs(0), bmBc(0), escape_item(escape_arg) {}
   longlong val_int();
   enum Functype functype() const { return LIKE_FUNC; }
   optimize_type select_optimize() const;