diff options
| -rw-r--r-- | mysql-test/r/func_str.result | 6 | ||||
| -rw-r--r-- | mysql-test/t/func_str.test | 8 | ||||
| -rw-r--r-- | sql/item_strfunc.cc | 11 |
3 files changed, 24 insertions, 1 deletions
diff --git a/mysql-test/r/func_str.result b/mysql-test/r/func_str.result index 1c560dfa8b4..8348ef12b0d 100644 --- a/mysql-test/r/func_str.result +++ b/mysql-test/r/func_str.result @@ -697,3 +697,9 @@ quote(ltrim(concat(' ', 'a'))) select quote(trim(concat(' ', 'a'))); quote(trim(concat(' ', 'a'))) 'a' +select trim(null from 'kate') as "must_be_null"; +must_be_null +NULL +select trim('xyz' from null) as "must_be_null"; +must_be_null +NULL diff --git a/mysql-test/t/func_str.test b/mysql-test/t/func_str.test index 5477a0ccb30..a5d95332caa 100644 --- a/mysql-test/t/func_str.test +++ b/mysql-test/t/func_str.test @@ -435,3 +435,11 @@ drop table t1; select quote(ltrim(concat(' ', 'a'))); select quote(trim(concat(' ', 'a'))); + +# +# Bug#7455 unexpected result: TRIM(<NULL> FROM <whatever>) gives NOT NULL +# According to ANSI if one of the TRIM arguments is NULL, then the result +# must be NULL too. +# +select trim(null from 'kate') as "must_be_null"; +select trim('xyz' from null) as "must_be_null"; diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc index 068878652e4..2a63c5355a4 100644 --- a/sql/item_strfunc.cc +++ b/sql/item_strfunc.cc @@ -1302,9 +1302,18 @@ String *Item_func_trim::val_str(String *str) return 0; /* purecov: inspected */ char buff[MAX_FIELD_WIDTH]; String tmp(buff,sizeof(buff),res->charset()); - String *remove_str= (arg_count==2) ? args[1]->val_str(&tmp) : &remove; uint remove_length; LINT_INIT(remove_length); + String *remove_str; /* The string to remove from res. */ + + if (arg_count == 2) + { + remove_str= args[1]->val_str(&tmp); + if ((null_value= args[1]->null_value)) + return 0; + } + else + remove_str= &remove; /* Default value. */ if (!remove_str || (remove_length=remove_str->length()) == 0 || remove_length > res->length()) |