type_blob.result, func_system.result, func_str.result, ctype_collate.result:

  fixing test results accordingly.
func_system.test:
  New test that illegal mix of collations does not happen anymore.
item_strfunc.h:
    safe_charset_converter() was added for system constants.
item_strfunc.cc:
  safe_charset_converter() was added for system constants.
item_func.cc, item.h, item.cc:
  Bug#8291: Illegal collation mix with USER() function.
  After discussion with PeterG and Serge, a new coercibility
  level for "system constants" was introduced, between
  COERRIBLE and IMPLICIT. Thus:
  SELECT col1 = USER() FROM t1; - is done according to col1 collation.
  SELECT 'string' = USER(); - is done according to USER() collation.
  At the same time, "nagg" and "strong" members were removed as unused.
item_create.cc:
  Version is a system constant too.

1 files changed, 8 insertions, 0 deletions

diff --git a/mysql-test/r/func_system.result b/mysql-test/r/func_system.result
index d3db2cc5151..d0ac9d781a4 100644
--- a/mysql-test/r/func_system.result
+++ b/mysql-test/r/func_system.result
@@ -68,3 +68,11 @@ drop table t1;
 select TRUE,FALSE,NULL;
 TRUE	FALSE	NULL
 1	0	NULL
+create table t1 (a char(10)) character set latin1;
+select * from t1 where a=version();
+a
+select * from t1 where a=database();
+a
+select * from t1 where a=user();
+a
+drop table t1;