Bug#14096619: UNABLE TO RESTORE DATABASE DUMP

Backport of Bug#13581962

mysql-test/r/cast.result:
  Added test result for Bug#13581962,Bug#14096619
mysql-test/t/cast.test:
  Added test case for Bug#13581962,Bug#14096619
sql/item_func.h:
  limit max length by MY_INT64_NUM_DECIMAL_DIGITS

mysql-test/r/cast.result

@@ -477,4 +477,22 @@ WHERE CAST(a as BINARY)=x'62736D697468'
 AND CAST(a AS BINARY)=x'65736D697468';
 a
 DROP TABLE t1;
+#
+# Bug#13581962 HIGH MEMORY USAGE ATTEMPT, THEN CRASH WITH 
+# LONGTEXT, UNION, USER VARIABLE
+# Bug#14096619 UNABLE TO RESTORE DATABASE DUMP
+#
+CREATE TABLE t1 AS SELECT CONCAT(CAST(REPEAT('9', 1000) AS SIGNED)),
+CONCAT(CAST(REPEAT('9', 1000) AS UNSIGNED));
+Warnings:
+Warning	1292	Truncated incorrect INTEGER value: '99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999'
+Warning	1292	Truncated incorrect INTEGER value: '99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999'
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `CONCAT(CAST(REPEAT('9', 1000) AS SIGNED))` varbinary(21) NOT NULL DEFAULT '',
+  `CONCAT(CAST(REPEAT('9', 1000) AS UNSIGNED))` varbinary(21) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+# End of test for Bug#13581962, Bug#14096619
 End of 5.1 tests

mysql-test/t/cast.test

@@ -309,4 +309,17 @@ WHERE CAST(a as BINARY)=x'62736D697468'
 
 DROP TABLE t1;
 
+--echo #
+--echo # Bug#13581962 HIGH MEMORY USAGE ATTEMPT, THEN CRASH WITH 
+--echo # LONGTEXT, UNION, USER VARIABLE
+--echo # Bug#14096619 UNABLE TO RESTORE DATABASE DUMP
+--echo #
+
+CREATE TABLE t1 AS SELECT CONCAT(CAST(REPEAT('9', 1000) AS SIGNED)),
+                          CONCAT(CAST(REPEAT('9', 1000) AS UNSIGNED));
+SHOW CREATE TABLE t1;
+DROP TABLE t1;
+
+--echo # End of test for Bug#13581962, Bug#14096619
+
 --echo End of 5.1 tests

sql/item_func.h

@@ -403,12 +403,17 @@ public:
 class Item_func_signed :public Item_int_func
 {
 public:
-  Item_func_signed(Item *a) :Item_int_func(a) {}
+  Item_func_signed(Item *a) :Item_int_func(a)
+  {
+    unsigned_flag= 0;
+  }
   const char *func_name() const { return "cast_as_signed"; }
   longlong val_int();
   longlong val_int_from_str(int *error);
   void fix_length_and_dec()
-  { max_length=args[0]->max_length; unsigned_flag=0; }
+  {
+    max_length= min(args[0]->max_length,MY_INT64_NUM_DECIMAL_DIGITS);
+  }
   virtual void print(String *str, enum_query_type query_type);
   uint decimal_precision() const { return args[0]->decimal_precision(); }
 };
@@ -417,13 +422,11 @@ public:
 class Item_func_unsigned :public Item_func_signed
 {
 public:
-  Item_func_unsigned(Item *a) :Item_func_signed(a) {}
-  const char *func_name() const { return "cast_as_unsigned"; }
-  void fix_length_and_dec()
+  Item_func_unsigned(Item *a) :Item_func_signed(a)
   {
-    max_length= min(args[0]->max_length, DECIMAL_MAX_PRECISION + 2);
-    unsigned_flag=1;
+    unsigned_flag= 1;
   }
+  const char *func_name() const { return "cast_as_unsigned"; }
   longlong val_int();
   virtual void print(String *str, enum_query_type query_type);
 };