bk commit into 5.0 tree (holyfoot:1.2474) BUG#27957

[holyfoot]

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ChangeSet@stripped, 2007-05-06 18:17:24+05:00, holyfoot@stripped +4 -0
  bug #27957 (cast as decimal does not check overflow, also inconsistent with group,
subselect)
  Item_decimal_typecast::val_decimal now checks the value if it's too
  big to fit the given precision/scale, truncates the value and issues
  a warning if the decimal gets off the range.

  mysql-test/r/cast.result@stripped, 2007-05-06 18:17:22+05:00, holyfoot@stripped +20 -3
    result added

  mysql-test/t/cast.test@stripped, 2007-05-06 18:17:22+05:00, holyfoot@stripped +11 -1
    testcase added and one old test fixed

  sql/item_func.cc@stripped, 2007-05-06 18:17:22+05:00, holyfoot@stripped +18 -0
    overflow checking added

  sql/item_func.h@stripped, 2007-05-06 18:17:22+05:00, holyfoot@stripped +3 -1
    store maximum possible value of the Item_decimal_typecast
    to check for overflow later

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	holyfoot
# Host:	hfmain.(none)
# Root:	/home/hf/work/27957/my50-27957

--- 1.335/sql/item_func.cc	2007-05-06 18:17:28 +05:00
+++ 1.336/sql/item_func.cc	2007-05-06 18:17:28 +05:00
@@ -1038,9 +1038,27 @@ longlong Item_decimal_typecast::val_int(
 
 my_decimal *Item_decimal_typecast::val_decimal(my_decimal *dec)
 {
+  bool orig_sign;
   my_decimal tmp_buf, *tmp= args[0]->val_decimal(&tmp_buf);
   if ((null_value= args[0]->null_value))
     return NULL;
+  orig_sign= tmp->sign();
+  tmp->sign(false);
+  max_value.sign(false);
+  if (my_decimal_cmp(tmp, &max_value) > 0)
+  {
+    char buf[100];
+    String err_st(buf, sizeof(buf), &my_charset_bin);
+    tmp->sign(orig_sign);
+    my_decimal2string(E_DEC_FATAL_ERROR, tmp, 0, 0, 0, &err_st);
+    push_warning_printf(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
+        ER_TRUNCATED_WRONG_VALUE,
+        ER(ER_TRUNCATED_WRONG_VALUE),
+        "DECIMAL", err_st.ptr());
+    max_value.sign(orig_sign);
+    return &max_value;
+  }
+  tmp->sign(orig_sign);
   my_decimal_round(E_DEC_FATAL_ERROR, tmp, decimals, FALSE, dec);
   return dec;
 }

--- 1.165/sql/item_func.h	2007-05-06 18:17:28 +05:00
+++ 1.166/sql/item_func.h	2007-05-06 18:17:28 +05:00
@@ -334,11 +334,13 @@ public:
 class Item_decimal_typecast :public Item_func
 {
   my_decimal decimal_value;
+  my_decimal max_value;
 public:
   Item_decimal_typecast(Item *a, int len, int dec) :Item_func(a)
   {
     max_length= len + 2;
     decimals= dec;
+    max_my_decimal(&max_value, len, dec);
   }
   String *val_str(String *str);
   double val_real();
@@ -346,7 +348,7 @@ public:
   my_decimal *val_decimal(my_decimal*);
   enum Item_result result_type () const { return DECIMAL_RESULT; }
   enum_field_types field_type() const { return MYSQL_TYPE_NEWDECIMAL; }
-  void fix_length_and_dec() {};
+  void fix_length_and_dec() {}
   const char *func_name() const { return "decimal_typecast"; }
   void print(String *);
 };

--- 1.49/mysql-test/r/cast.result	2007-05-06 18:17:28 +05:00
+++ 1.50/mysql-test/r/cast.result	2007-05-06 18:17:28 +05:00
@@ -376,9 +376,9 @@ cast(-1e18 as decimal(22,2))
 -1000000000000000000.00
 create table t1(s1 time);
 insert into t1 values ('11:11:11');
-select cast(s1 as decimal(7,2)) from t1;
-cast(s1 as decimal(7,2))
-111111.00
+select cast(s1 as decimal(7,1)) from t1;
+cast(s1 as decimal(7,1))
+111111.0
 drop table t1;
 CREATE TABLE t1 (v varchar(10), tt tinytext, t text,
 mt mediumtext, lt longtext);
@@ -401,4 +401,21 @@ hex(cast('a' as binary(2)))
 select hex(cast('a' as char(2) binary));
 hex(cast('a' as char(2) binary))
 61
+create table t1 (d DECIMAL(10, 5));
+insert into t1 values (11.1234), (-11.1234);
+select cast(d as DECIMAL(3,2)) d_c from t1;
+d_c
+9.99
+-9.99
+Warnings:
+Warning	1292	Truncated incorrect DECIMAL value: '11.12340'
+Warning	1292	Truncated incorrect DECIMAL value: '-11.12340'
+select * from (select cast(d as DECIMAL(3,2)) d_c from t1) t;
+d_c
+9.99
+-9.99
+Warnings:
+Warning	1292	Truncated incorrect DECIMAL value: '11.12340'
+Warning	1292	Truncated incorrect DECIMAL value: '-11.12340'
+drop table t1;
 End of 5.0 tests

--- 1.35/mysql-test/t/cast.test	2007-05-06 18:17:28 +05:00
+++ 1.36/mysql-test/t/cast.test	2007-05-06 18:17:28 +05:00
@@ -201,7 +201,7 @@ select cast(-1e18 as decimal(22,2));
 
 create table t1(s1 time);
 insert into t1 values ('11:11:11');
-select cast(s1 as decimal(7,2)) from t1;
+select cast(s1 as decimal(7,1)) from t1;
 drop table t1;
 
 #
@@ -230,5 +230,15 @@ set names latin1;
 select hex(cast('a' as char(2) binary));
 select hex(cast('a' as binary(2)));
 select hex(cast('a' as char(2) binary));
+
+#
+# Bug #27957 cast as decimal does not check overflow, also inconsistent with group,
subselect 
+#
+
+create table t1 (d DECIMAL(10, 5));
+insert into t1 values (11.1234), (-11.1234);
+select cast(d as DECIMAL(3,2)) d_c from t1;
+select * from (select cast(d as DECIMAL(3,2)) d_c from t1) t;
+drop table t1;
 
 --echo End of 5.0 tests