diff options
| -rw-r--r-- | mysql-test/r/func_str.result | 3 | ||||
| -rw-r--r-- | mysql-test/t/func_str.test | 6 | ||||
| -rw-r--r-- | sql/item_strfunc.cc | 5 | ||||
| -rw-r--r-- | sql/sql_string.h | 1 |
4 files changed, 14 insertions, 1 deletions
diff --git a/mysql-test/r/func_str.result b/mysql-test/r/func_str.result index e07ee4f0add..345832387bd 100644 --- a/mysql-test/r/func_str.result +++ b/mysql-test/r/func_str.result @@ -673,3 +673,6 @@ c1 c2 2147483647 4294967295 -2147483648 0 drop table t1; +select left(1234, 3) + 0; +left(1234, 3) + 0 +123 diff --git a/mysql-test/t/func_str.test b/mysql-test/t/func_str.test index 61d0326f7dd..e7852df40b3 100644 --- a/mysql-test/t/func_str.test +++ b/mysql-test/t/func_str.test @@ -402,3 +402,9 @@ insert into t1 values ('-21474836461','-21474836461'); show warnings; select * from t1; drop table t1; + +# +# Bug #4878: LEFT() in integer/float context +# + +select left(1234, 3) + 0; diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc index d3493e1fad1..995627766c0 100644 --- a/sql/item_strfunc.cc +++ b/sql/item_strfunc.cc @@ -984,7 +984,10 @@ String *Item_func_left::val_str(String *str) return &my_empty_string; if (res->length() <= (uint) length) return res; - str_value.set(*res, 0, res->charpos(length)); + if (&str_value == res) + str_value.length(res->charpos(length)); + else + str_value.set(*res, 0, res->charpos(length)); return &str_value; } diff --git a/sql/sql_string.h b/sql/sql_string.h index 01329c45a98..0179b3ebadc 100644 --- a/sql/sql_string.h +++ b/sql/sql_string.h @@ -98,6 +98,7 @@ public: void set(String &str,uint32 offset,uint32 arg_length) { + DBUG_ASSERT(&str != this); free(); Ptr=(char*) str.ptr()+offset; str_length=arg_length; alloced=0; if (str.Alloced_length) |