Allow storing "+456" then decimal declared unsigned

mysql-test/r/type_decimal.result:
  Change test results according to this
sql/field.cc:
  Allow storing "+1234" in unsigned decimal as Monty asked.
  Old code is left for a while

mysql-test/r/type_decimal.result

@@ -199,15 +199,15 @@ select * from t1;
 a
 0.00
 0.00
-0.00
++0.00
-01.00
 01.00
++01.00
 0.00
 0.00
-0.10
++0.10
 0.10
 00000001.00
-00000001.00
++0000001.00
 0.00
 99999999.99
 99999999.99
@@ -316,9 +316,9 @@ select * from t1;
 a
 0
 0
-1
++1
 01
-0000000001
++000000001
 1234567890
 9999999999
 drop  table t1;

sql/field.cc

@@ -431,8 +431,9 @@ void Field_decimal::store(const char *from,uint len)
   {
     sign_char= *from++;
     /*
-      Unsigned can't have any flag. So we'll just drop "+"
+      We allow "+" for unsigned decimal unless defined different
-      and will overflow on "-"
+      Both options allowed as one may wish not to have "+" for unsigned numbers
+      because of data processing issues
     */ 
     if (unsigned_flag)  
     { 
@@ -441,8 +442,14 @@ void Field_decimal::store(const char *from,uint len)
         Field_decimal::overflow(1);
         return;
       }
+      /* 
+        Defining this will not store "+" for unsigned decimal type even if
+	it is passed in numeric string. This will make some tests to fail
+      */	 
+#ifdef DONT_ALLOW_UNSIGNED_PLUS      
       else 
         sign_char=0;
+#endif 	
     }
   }