MDEV-17759 Assertion `precision > 0' failed in decimal_bin_size upon CREATE TABLE .. SELECT

mysql-test/main/func_hybrid_type.result

@@ -3753,5 +3753,23 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
 #
+# MDEV-17759 Assertion `precision > 0' failed in decimal_bin_size upon CREATE TABLE .. SELECT
+#
+SET sql_mode='';
+CREATE TABLE t1 (d DECIMAL(43,0) UNSIGNED);
+INSERT INTO t1 VALUES (1);
+CREATE TABLE t2 AS SELECT
+IFNULL(SLEEP(0.01), NULL DIV d) AS f0,
+IFNULL(SLEEP(0.01), '' DIV d) AS f1
+FROM t1;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `f0` decimal(1,0) DEFAULT NULL,
+  `f1` decimal(1,0) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1, t2;
+SET sql_mode=DEFAULT;
+#
 # End of 10.3 tests
 #

mysql-test/main/func_hybrid_type.test

@@ -611,6 +611,22 @@ CREATE TABLE t1 AS SELECT
 SHOW CREATE TABLE t1;
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-17759 Assertion `precision > 0' failed in decimal_bin_size upon CREATE TABLE .. SELECT
+--echo #
+
+SET sql_mode='';
+CREATE TABLE t1 (d DECIMAL(43,0) UNSIGNED);
+INSERT INTO t1 VALUES (1);
+CREATE TABLE t2 AS SELECT
+  IFNULL(SLEEP(0.01), NULL DIV d) AS f0,
+  IFNULL(SLEEP(0.01), '' DIV d) AS f1
+FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t1, t2;
+SET sql_mode=DEFAULT;
+
+
 --echo #
 --echo # End of 10.3 tests
 --echo #

mysql-test/main/func_math.result

@@ -1285,3 +1285,36 @@ E59B9BE4BA94E585AD	2914501801
 E4B883E585ABE4B99D	2374586519
 DROP TABLE t1;
 SET NAMES default;
+#
+# MDEV-17759 Assertion `precision > 0' failed in decimal_bin_size upon CREATE TABLE .. SELECT
+#
+SET sql_mode='';
+CREATE TABLE t1 (d DECIMAL(43,0) UNSIGNED);
+INSERT INTO t1 VALUES (1);
+CREATE TABLE t2 AS SELECT
+NULL DIV d AS d_null,
+'' DIV d AS d_empty_string,
+X'32' DIV d AS d_hex_string2,
+X'3232' DIV d AS d_hex_string4,
+TIME(0) DIV d AS d_time,
+CURRENT_DATE DIV d AS d_date,
+CURRENT_TIMESTAMP DIV d AS d_datetime
+FROM t1;
+Warnings:
+Warning	1292	Truncated incorrect DECIMAL value: ''
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `d_null` int(1) unsigned DEFAULT NULL,
+  `d_empty_string` int(1) unsigned DEFAULT NULL,
+  `d_hex_string2` int(1) unsigned DEFAULT NULL,
+  `d_hex_string4` int(2) unsigned DEFAULT NULL,
+  `d_time` int(7) unsigned DEFAULT NULL,
+  `d_date` int(8) unsigned DEFAULT NULL,
+  `d_datetime` bigint(14) unsigned DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1, t2;
+SET sql_mode=DEFAULT;
+#
+# End of 10.3 tests
+#

mysql-test/main/func_math.test

@@ -897,3 +897,28 @@ LOAD DATA INFILE '../../std_data/loaddata_utf8.dat' INTO TABLE t1 CHARACTER SET
 SELECT HEX(a), CRC32(a) from t1;
 DROP TABLE t1;
 SET NAMES default;
+
+--echo #
+--echo # MDEV-17759 Assertion `precision > 0' failed in decimal_bin_size upon CREATE TABLE .. SELECT
+--echo #
+
+SET sql_mode='';
+CREATE TABLE t1 (d DECIMAL(43,0) UNSIGNED);
+INSERT INTO t1 VALUES (1);
+CREATE TABLE t2 AS SELECT
+  NULL DIV d AS d_null,
+  '' DIV d AS d_empty_string,
+  X'32' DIV d AS d_hex_string2,
+  X'3232' DIV d AS d_hex_string4,
+  TIME(0) DIV d AS d_time,
+  CURRENT_DATE DIV d AS d_date,
+  CURRENT_TIMESTAMP DIV d AS d_datetime
+FROM t1;
+SHOW CREATE TABLE t2;
+DROP TABLE t1, t2;
+SET sql_mode=DEFAULT;
+
+
+--echo #
+--echo # End of 10.3 tests
+--echo #

sql/item_func.cc

@@ -1752,13 +1752,9 @@ longlong Item_func_int_div::val_int()
 
 bool Item_func_int_div::fix_length_and_dec()
 {
-  Item_result argtype= args[0]->result_type();
-  /* use precision ony for the data type it is applicable for and valid */
-  uint32 char_length= args[0]->max_char_length() -
-                      (argtype == DECIMAL_RESULT || argtype == INT_RESULT ?
-                       args[0]->decimals : 0);
-  fix_char_length(char_length > MY_INT64_NUM_DECIMAL_DIGITS ?
-                  MY_INT64_NUM_DECIMAL_DIGITS : char_length);
+  uint32 prec= args[0]->decimal_int_part();
+  set_if_smaller(prec, MY_INT64_NUM_DECIMAL_DIGITS);
+  fix_char_length(prec);
   maybe_null=1;
   unsigned_flag=args[0]->unsigned_flag | args[1]->unsigned_flag;
   return false;