bzr push into mysql-5.0-bugteam branch (holyfoot:2716 to 2717) Bug#31616

[Alexey Botchkov]

 2717 Alexey Botchkov	2008-11-17
      Bug#31616 div_precision_increment description looks wrong
      
      Item_func_div didn't calculate the precision of the result properly.
        The result of 5/0.0001 is 5000 so we have to add decimals of the divisor
        to the planned precision.
      
      per-file comments:
        mysql-test/r/type_newdecimal.result
      Bug#31616 div_precision_increment description looks wrong
          test result fixed
      
        mysql-test/t/type_newdecimal.test
      Bug#31616 div_precision_increment description looks wrong
          test case
      
        sql/item_func.cc
      Bug#31616 div_precision_increment description looks wrong
          precision must be increased with args[1]->decimals parameter
modified:
  mysql-test/r/type_newdecimal.result
  mysql-test/t/type_newdecimal.test
  sql/item_func.cc

 2716 Gleb Shchepa	2008-11-14
      Bug #40021: Renaming view fails, archived .frm for view is
                  missing after downgrade
      
      Obsolete arc/ directory and view .frm file backup support
      has been removed by the patch for bug 17823. However, that
      bugfix caused a problem with "live downgrades" of the
      server: if we rename some view 4 times under 5.1.29/5.0.72
      and then try to rename it under 5.1.28/5.0.70 on the same
      database, the server fails with a error:
      
        query 'RENAME TABLE ... TO ...' failed: 6: Error on
        delete of '....frm-0001' (Errcode: 2)
      
      Also .frm file of that view may be lost (renamed to .frm~).
      
      The server failed because it tried to rename latest 3
      backup .frm files renaming the view: the server used an
      integer value of the "revision" field of .frm file to
      extract those file names. After the fix for bug 17823 those
      files were not created/maintained any more, however the
      "revision" field was incremented as usual. So, the server
      failed renaming non existent files.
      
      This fix solves the problem by removing the support for
      "revision" .frm file field:
      1. New server silently ignores existent "revision" fields
         in old .frm files and never write it down;
      2. Old server assumes, that missing "revision" field in new
         .frm files means default value of 0.
      3. Accordingly to the fix for bug 17823 the new server
         drops arc/ directory on alter/rename view, so after
         "live downgrade" old server begins maintenance of the
         arc/ directory from scratch without conflicts with .frm
         files.
modified:
  sql/parse_file.cc
  sql/parse_file.h
  sql/sql_db.cc
  sql/sql_trigger.cc
  sql/sql_view.cc
  sql/table.h

=== modified file 'mysql-test/r/type_newdecimal.result'
--- a/mysql-test/r/type_newdecimal.result	2008-08-15 19:46:21 +0000
+++ b/mysql-test/r/type_newdecimal.result	2008-11-17 15:41:09 +0000
@@ -1524,4 +1524,19 @@ select (1.20396873 * 0.89550000 * 0.6800
 (1.20396873 * 0.89550000 * 0.68000000 * 1.08721696 * 0.99500000 *
 1.01500000 * 1.01500000 * 0.99500000)
 0.812988073953673124592306939480
+create table t1 as select 5.05 / 0.014;
+Warnings:
+Note	1265	Data truncated for column '5.05 / 0.014' at row 1
+show warnings;
+Level	Code	Message
+Note	1265	Data truncated for column '5.05 / 0.014' at row 1
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `5.05 / 0.014` decimal(10,6) default NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+select * from t1;
+5.05 / 0.014
+360.714286
+DROP TABLE t1;
 End of 5.0 tests

=== modified file 'mysql-test/t/type_newdecimal.test'
--- a/mysql-test/t/type_newdecimal.test	2008-08-15 19:46:21 +0000
+++ b/mysql-test/t/type_newdecimal.test	2008-11-17 15:41:09 +0000
@@ -1225,4 +1225,14 @@ DROP TABLE t1;
 select (1.20396873 * 0.89550000 * 0.68000000 * 1.08721696 * 0.99500000 *
         1.01500000 * 1.01500000 * 0.99500000);
 
+#
+# Bug #31616 div_precision_increment description looks wrong 
+#
+
+create table t1 as select 5.05 / 0.014;
+show warnings;
+show create table t1;
+select * from t1;
+DROP TABLE t1;
+
 --echo End of 5.0 tests

=== modified file 'sql/item_func.cc'
--- a/sql/item_func.cc	2008-07-30 11:07:37 +0000
+++ b/sql/item_func.cc	2008-11-17 15:41:09 +0000
@@ -1316,8 +1316,10 @@ my_decimal *Item_func_div::decimal_op(my
 
 void Item_func_div::result_precision()
 {
-  uint arg_prec= args[0]->decimal_precision() + prec_increment;
-  uint precision=min(arg_prec, DECIMAL_MAX_PRECISION);
+  uint precision=min(args[0]->decimal_precision() + 
+                     args[1]->decimals + prec_increment,
+                     DECIMAL_MAX_PRECISION);
+
   /* Integer operations keep unsigned_flag if one of arguments is unsigned */
   if (result_type() == INT_RESULT)
     unsigned_flag= args[0]->unsigned_flag | args[1]->unsigned_flag;