From f00e6bd75d24e311016cd72449ed678c0172f6e6 Mon Sep 17 00:00:00 2001
From: unknown <holyfoot/hf@mysql.com/deer.(none)>
Date: Mon, 30 Oct 2006 09:52:50 +0400
Subject: [PATCH] Bug #8663 (cant use bigint as input to CAST)

decimal->ulong conversion fixed to assign max possible ULONG if decimal
is bigger
Item_func_unsigned now handles DECIMAL parameter separately as we can't
rely on decimal::val_int result here.


mysql-test/r/type_newdecimal.result:
  result fixed
mysql-test/t/type_newdecimal.test:
  testcase
sql/item_func.cc:
  DECIMAL_RESULT should be handled separately here as it's
  always signed.
strings/decimal.c:
  here we assign max possible ULONG if the decimal value is bigger
---
 mysql-test/r/type_newdecimal.result | 5 +++++
 mysql-test/t/type_newdecimal.test   | 6 ++++++
 sql/item_func.cc                    | 9 ++++++++-
 strings/decimal.c                   | 2 +-
 4 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/mysql-test/r/type_newdecimal.result b/mysql-test/r/type_newdecimal.result
index 33f1ece0390..cacb945df85 100644
--- a/mysql-test/r/type_newdecimal.result
+++ b/mysql-test/r/type_newdecimal.result
@@ -1412,3 +1412,8 @@ i2	count(distinct j)
 1.0	2
 2.0	2
 drop table t1;
+select cast(19999999999999999999 as unsigned);
+cast(19999999999999999999 as unsigned)
+18446744073709551615
+Warnings:
+Error	1292	Truncated incorrect DECIMAL value: ''
diff --git a/mysql-test/t/type_newdecimal.test b/mysql-test/t/type_newdecimal.test
index de1ebd74d17..cb85f14ee47 100644
--- a/mysql-test/t/type_newdecimal.test
+++ b/mysql-test/t/type_newdecimal.test
@@ -1108,3 +1108,9 @@ insert into t1 values (1,1), (1,2), (2,3), (2,4);
 select i, count(distinct j) from t1 group by i;
 select i+0.0 as i2, count(distinct j) from t1 group by i2;
 drop table t1;
+
+#
+# Bug #8663 (cant use bigint as input to CAST)
+#
+select cast(19999999999999999999 as unsigned);
+
diff --git a/sql/item_func.cc b/sql/item_func.cc
index a294bbd7a71..38294d52a5b 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -964,7 +964,14 @@ longlong Item_func_unsigned::val_int()
   longlong value;
   int error;
 
-  if (args[0]->cast_to_int_type() != STRING_RESULT)
+  if (args[0]->cast_to_int_type() == DECIMAL_RESULT)
+  {
+    my_decimal tmp, *dec= args[0]->val_decimal(&tmp);
+    if (!(null_value= args[0]->null_value))
+      my_decimal2int(E_DEC_FATAL_ERROR, dec, 1, &value);
+    return value;
+  }
+  else if (args[0]->cast_to_int_type() != STRING_RESULT)
   {
     value= args[0]->val_int();
     null_value= args[0]->null_value; 
diff --git a/strings/decimal.c b/strings/decimal.c
index 5a0bc0968b6..e0b06685521 100644
--- a/strings/decimal.c
+++ b/strings/decimal.c
@@ -1036,7 +1036,7 @@ int decimal2ulonglong(decimal_t *from, ulonglong *to)
     x=x*DIG_BASE + *buf++;
     if (unlikely(y > ((ulonglong) ULONGLONG_MAX/DIG_BASE) || x < y))
     {
-      *to=y;
+      *to=ULONGLONG_MAX;
       return E_DEC_OVERFLOW;
     }
   }