diff options
Diffstat (limited to 'sql')
| -rw-r--r-- | sql/item.cc | 9 | ||||
| -rw-r--r-- | sql/item_func.h | 11 |
2 files changed, 17 insertions, 3 deletions
diff --git a/sql/item.cc b/sql/item.cc index 08599f1d486..015f5591c5d 100644 --- a/sql/item.cc +++ b/sql/item.cc @@ -533,7 +533,14 @@ uint Item::decimal_precision() const unsigned_flag); return MY_MIN(prec, DECIMAL_MAX_PRECISION); } - return MY_MIN(max_char_length(), DECIMAL_MAX_PRECISION); + uint res= max_char_length(); + /* + Return at least one decimal digit, even if Item::max_char_length() + returned 0. This is important to avoid attempts to create fields of types + INT(0) or DECIMAL(0,0) when converting NULL or empty strings to INT/DECIMAL: + CREATE TABLE t1 AS SELECT CONVERT(NULL,SIGNED) AS a; + */ + return res ? MY_MIN(res, DECIMAL_MAX_PRECISION) : 1; } diff --git a/sql/item_func.h b/sql/item_func.h index 4a55bd68453..56d7c190181 100644 --- a/sql/item_func.h +++ b/sql/item_func.h @@ -626,8 +626,15 @@ public: longlong val_int_from_str(int *error); void fix_length_and_dec() { - fix_char_length(MY_MIN(args[0]->max_char_length(), - MY_INT64_NUM_DECIMAL_DIGITS)); + uint32 char_length= MY_MIN(args[0]->max_char_length(), + MY_INT64_NUM_DECIMAL_DIGITS); + /* + args[0]->max_char_length() can return 0. + Reserve max_length to fit at least one character for one digit, + plus one character for the sign (if signed). + */ + set_if_bigger(char_length, 1 + (unsigned_flag ? 0 : 1)); + fix_char_length(char_length); } virtual void print(String *str, enum_query_type query_type); uint decimal_precision() const { return args[0]->decimal_precision(); } |