Bug#19371 VARBINARY() have trailing zeros after upgrade from 4.1

 - Detect if a table has field of type MYSQL_TYPE_VAR_STRING while running
   "CHECK TABLE t FOR UPGRADE" and indicate it need to be fixed
   with "REPAIR TABLE t".
 - When running a "REPAIR TABLE t" or "ALTER TABLE t FORCE" on the above
   table, install a special copy function to trim off the trailing spaces
   which we safely can say that the pre 5.0 mysqld didn't put there. 


mysql-test/r/varbinary.result:
  Add test to see that a table with varbinary from 4.1 can be REPAIRED
mysql-test/t/varbinary.test:
  Add test to see that a table with varbinary from 4.1 can be REPAIRED
sql/field_conv.cc:
  Add new field copy function 'do_field_varbinary_pre50' used for copying
  between MYSQL_TYPE_VAR_STRING and MYSQL_TYPE_VARCHAR. It will remove trailing
  spaces from the field as MySQL <= 4.1 never stores the trailing spaces for
  a MYSQL_TYPE_VAR_STRING.
  Install this new copy function in ALTER TABLEs list of functions to use for
  copying data during and alter if from field is a <= 4.1 varbinary and to
  field is 5.0 varbinary.
sql/handler.cc:
  If the table has a pre 5.0 varbinary, table not to be altered so the field
  type is upgraded to 5.0 version and trailing space can be trimmed.
mysql-test/std_data/bug19371.MYD:
  New BitKeeper file ``mysql-test/std_data/bug19371.MYD''
mysql-test/std_data/bug19371.MYI:
  New BitKeeper file ``mysql-test/std_data/bug19371.MYI''
mysql-test/std_data/bug19371.frm:
  New BitKeeper file ``mysql-test/std_data/bug19371.frm''

1 files changed, 24 insertions, 0 deletions

diff --git a/sql/field_conv.cc b/sql/field_conv.cc
index 95ff985376d..3286695d733 100644
--- a/sql/field_conv.cc
+++ b/sql/field_conv.cc
@@ -309,6 +309,21 @@ static void do_field_string(Copy_field *copy)
 }
 
 
+static void do_field_varbinary_pre50(Copy_field *copy)
+{
+  char buff[MAX_FIELD_WIDTH];
+  copy->tmp.set_quick(buff,sizeof(buff),copy->tmp.charset());
+  copy->from_field->val_str(&copy->tmp);
+
+  /* Use the same function as in 4.1 to trim trailing spaces */
+  uint length= my_lengthsp_8bit(&my_charset_bin, copy->tmp.c_ptr_quick(),
+                                copy->from_field->field_length);
+
+  copy->to_field->store(copy->tmp.c_ptr_quick(), length,
+                        copy->tmp.charset());
+}
+
+
 static void do_field_int(Copy_field *copy)
 {
   longlong value= copy->from_field->val_int();
@@ -571,6 +586,15 @@ void (*Copy_field::get_copy_func(Field *to,Field *from))(Copy_field*)
     if (from->result_type() == STRING_RESULT)
     {
       /*
+        Detect copy from pre 5.0 varbinary to varbinary as of 5.0 and
+        use special copy function that removes trailing spaces and thus
+        repairs data.
+      */
+      if (from->type() == MYSQL_TYPE_VAR_STRING && !from->has_charset() &&
+          to->type() == MYSQL_TYPE_VARCHAR && !to->has_charset())
+        return do_field_varbinary_pre50;
+
+      /*
         If we are copying date or datetime's we have to check the dates
         if we don't allow 'all' dates.
       */