Fix for bug #12694 (float(1,2) field error)

mysql-test/t/type_float.test

@@ -147,3 +147,12 @@ select * from t1 where reckey=1.09E2;
 drop table t1;
 
 # End of 4.1 tests
+
+#
+# bug #12694 (float(m,d) specifications)
+#
+
+--error 1427
+create table t1 (s1 float(0,2));
+--error 1427
+create table t1 (s1 float(1,2));

sql/sql_parse.cc

@@ -5752,19 +5752,31 @@ new_create_field(THD *thd, char *field_name, enum_field_types type,
       new_field->decimals= NOT_FIXED_DEC;
       break;
     }
-    if (!length)
+    if (!length && !decimals)
     {
       new_field->length =  FLT_DIG+6;
       new_field->decimals= NOT_FIXED_DEC;
     }
+    if (new_field->length < new_field->decimals &&
+        new_field->decimals != NOT_FIXED_DEC)
+    {
+      my_error(ER_SCALE_BIGGER_THAN_PRECISION, MYF(0), field_name);
+      DBUG_RETURN(NULL);
+    }
     break;
   case FIELD_TYPE_DOUBLE:
     allowed_type_modifier= AUTO_INCREMENT_FLAG;
-    if (!length)
+    if (!length && !decimals)
     {
       new_field->length = DBL_DIG+7;
       new_field->decimals=NOT_FIXED_DEC;
     }
+    if (new_field->length < new_field->decimals &&
+        new_field->decimals != NOT_FIXED_DEC)
+    {
+      my_error(ER_SCALE_BIGGER_THAN_PRECISION, MYF(0), field_name);
+      DBUG_RETURN(NULL);
+    }
     break;
   case FIELD_TYPE_TIMESTAMP:
     if (!length)