Bug #29804 UDF parameters don't contain correct string length

Previously, UDF *_init functions were passed constant strings with erroneous lengths.
The length came from the containing variable's size, not the length of the value itself.

Now the *_init functions get the constant as a null terminated string with the correct
length supplied.


mysql-test/r/udf.result:
  Test case to check constants passed UDFs.
mysql-test/t/udf.test:
  Test case to check constants passed UDFs.
sql/item_func.cc:
  UDF _init functions are now passed the length of the constants, rather than the max
  length of the var containing the constant.
sql/udf_example.c:
  Added check_const_len functions. The check_const_len_init functions checks that the
  lengths of constants are correctly passed.

1 files changed, 24 insertions, 0 deletions

diff --git a/mysql-test/r/udf.result b/mysql-test/r/udf.result
index bba722e523c..f1e47905f5d 100644
--- a/mysql-test/r/udf.result
+++ b/mysql-test/r/udf.result
@@ -334,4 +334,28 @@ Qcache_queries_in_cache	0
 drop table t1;
 drop function metaphon;
 set GLOBAL query_cache_size=default;
+CREATE TABLE const_len_bug (
+str_const varchar(4000),
+result1 varchar(4000),
+result2 varchar(4000)
+);
+CREATE TRIGGER check_const_len_trigger BEFORE INSERT ON const_len_bug FOR EACH ROW BEGIN
+set NEW.str_const = 'bar';
+set NEW.result2 = check_const_len(NEW.str_const);
+END |
+CREATE PROCEDURE check_const_len_sp (IN str_const VARCHAR(4000))
+BEGIN
+DECLARE result VARCHAR(4000);
+SET result = check_const_len(str_const);
+insert into const_len_bug values(str_const, result, "");
+END |
+CREATE FUNCTION check_const_len RETURNS string SONAME "UDF_EXAMPLE_LIB";
+CALL check_const_len_sp("foo");
+SELECT * from const_len_bug;
+str_const	result1	result2
+bar	Correct length	Correct length
+DROP FUNCTION check_const_len;
+DROP PROCEDURE check_const_len_sp;
+DROP TRIGGER check_const_len_trigger;
+DROP TABLE const_len_bug;
 End of 5.0 tests.