MDEV-9653 Assertion `length || !scale' failed in uint my_decimal_length_to_precision(uint, uint, bool)

MDEV-9752 Wrong data type for COALEASCE(?,1) in prepared statements

Author: Alexander Barkov

mysql-test/r/func_hybrid_type.result

@@ -2175,10 +2175,10 @@ def					case_____a_b	12	19	19	Y	128	0	63
 def					case_____b_a	12	19	19	Y	128	0	63
 def					coalesce_a_b	12	19	19	Y	128	0	63
 def					coalesce_b_a	12	19	19	Y	128	0	63
-def					if_______a_b	12	10	19	Y	128	0	63
-def					if_______b_a	12	10	19	Y	128	0	63
-def					ifnull___a_b	12	10	19	Y	128	0	63
-def					ifnull___b_a	12	10	19	Y	128	0	63
+def					if_______a_b	12	19	19	Y	128	0	63
+def					if_______b_a	12	19	19	Y	128	0	63
+def					ifnull___a_b	12	19	19	Y	128	0	63
+def					ifnull___b_a	12	19	19	Y	128	0	63
 def					least____a_b	12	10	19	Y	128	0	63
 def					least____b_a	12	10	19	Y	128	0	63
 def					greatest_a_b	12	10	19	Y	128	0	63
@@ -3396,5 +3396,36 @@ c1
 DROP TABLE t2;
 DROP TABLE t1;
 #
+# MDEV-9653 Assertion `length || !scale' failed in uint my_decimal_length_to_precision(uint, uint, bool)
+#
+SELECT CASE 0 WHEN 1 THEN (CASE 2 WHEN 3 THEN NULL END) WHEN 4 THEN 5 END;
+CASE 0 WHEN 1 THEN (CASE 2 WHEN 3 THEN NULL END) WHEN 4 THEN 5 END
+NULL
+SELECT CASE 0 WHEN 1 THEN (COALESCE(NULL)) WHEN 4 THEN 5 END;
+CASE 0 WHEN 1 THEN (COALESCE(NULL)) WHEN 4 THEN 5 END
+NULL
+SELECT CASE WHEN TRUE THEN COALESCE(NULL) ELSE 4 END;
+CASE WHEN TRUE THEN COALESCE(NULL) ELSE 4 END
+NULL
+SELECT COALESCE(COALESCE(NULL), 1.1) AS c0, IF(0, COALESCE(NULL), 1.1) AS c1;
+Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
+def					c0	246	4	3	Y	32896	1	63
+def					c1	246	4	3	Y	32896	1	63
+c0	c1
+1.1	1.1
+#
+# MDEV-9752 Wrong data type for COALEASCE(?,1) in prepared statements
+#
+PREPARE stmt FROM "CREATE TABLE t1 AS SELECT CONCAT(COALESCE(?,1)) AS a, CONCAT(CASE WHEN TRUE THEN ? ELSE 1 END) AS b";
+SET @a=1;
+EXECUTE stmt USING @a,@a;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` varchar(21) DEFAULT NULL,
+  `b` varchar(21) DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+DROP TABLE t1;
+#
 # End of 10.1 tests
 #

mysql-test/r/type_num.result

@@ -1220,3 +1220,31 @@ Warning	1292	Truncated incorrect DOUBLE value: '1E+'
 #
 # End of 10.0 tests
 #
+#
+# Start of 10.1 tests
+#
+#
+# MDEV-9653 Assertion `length || !scale' failed in uint my_decimal_length_to_precision(uint, uint, bool)
+#
+SELECT NULL+1 AS c0,
+COALESCE(NULL)+1 AS c2,
+COALESCE(COALESCE(NULL))+1 AS c3,
+''+1 AS c4,
+COALESCE('')+1 AS c5,
+COALESCE(COALESCE(''))+1 AS c6;
+Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
+def					c0	5	17	0	Y	32896	0	63
+def					c2	5	17	0	Y	32896	0	63
+def					c3	5	17	0	Y	32896	0	63
+def					c4	5	23	1	N	32897	31	63
+def					c5	5	17	1	N	32897	0	63
+def					c6	5	17	1	N	32897	0	63
+c0	c2	c3	c4	c5	c6
+NULL	NULL	NULL	1	1	1
+Warnings:
+Warning	1292	Truncated incorrect DOUBLE value: ''
+Warning	1292	Truncated incorrect DOUBLE value: ''
+Warning	1292	Truncated incorrect DOUBLE value: ''
+#
+# Start of 10.1 tests
+#

mysql-test/t/func_hybrid_type.test

@@ -433,6 +433,29 @@ DROP TABLE t2;
 DROP TABLE t1;
 
 
+--echo #
+--echo # MDEV-9653 Assertion `length || !scale' failed in uint my_decimal_length_to_precision(uint, uint, bool)
+--echo #
+SELECT CASE 0 WHEN 1 THEN (CASE 2 WHEN 3 THEN NULL END) WHEN 4 THEN 5 END;
+SELECT CASE 0 WHEN 1 THEN (COALESCE(NULL)) WHEN 4 THEN 5 END;
+SELECT CASE WHEN TRUE THEN COALESCE(NULL) ELSE 4 END;
+
+--disable_ps_protocol
+--enable_metadata
+SELECT COALESCE(COALESCE(NULL), 1.1) AS c0, IF(0, COALESCE(NULL), 1.1) AS c1;
+--disable_metadata
+--enable_ps_protocol
+
+
+--echo #
+--echo # MDEV-9752 Wrong data type for COALEASCE(?,1) in prepared statements
+--echo #
+PREPARE stmt FROM "CREATE TABLE t1 AS SELECT CONCAT(COALESCE(?,1)) AS a, CONCAT(CASE WHEN TRUE THEN ? ELSE 1 END) AS b";
+SET @a=1;
+EXECUTE stmt USING @a,@a;
+SHOW CREATE TABLE t1;
+DROP TABLE t1;
+
 --echo #
 --echo # End of 10.1 tests
 --echo #

mysql-test/t/type_num.test

@@ -681,3 +681,27 @@ SELECT
 --echo #
 --echo # End of 10.0 tests
 --echo #
+
+--echo #
+--echo # Start of 10.1 tests
+--echo #
+
+--echo #
+--echo # MDEV-9653 Assertion `length || !scale' failed in uint my_decimal_length_to_precision(uint, uint, bool)
+--echo #
+
+--disable_ps_protocol
+--enable_metadata
+SELECT NULL+1 AS c0,
+       COALESCE(NULL)+1 AS c2,
+       COALESCE(COALESCE(NULL))+1 AS c3,
+       ''+1 AS c4,
+       COALESCE('')+1 AS c5,
+       COALESCE(COALESCE(''))+1 AS c6;
+--disable_metadata
+--enable_ps_protocol
+
+
+--echo #
+--echo # Start of 10.1 tests
+--echo #

sql/item_cmpfunc.cc

@@ -2246,50 +2246,6 @@ void Item_func_between::print(String *str, enum_query_type query_type)
 }
 
 
-void
-Item_func_case_abbreviation2::fix_length_and_dec2(Item **args)
-{
-  uint32 char_length;
-  set_handler_by_field_type(agg_field_type(args, 2, true));
-  maybe_null=args[0]->maybe_null || args[1]->maybe_null;
-  decimals= MY_MAX(args[0]->decimals, args[1]->decimals);
-  unsigned_flag= args[0]->unsigned_flag && args[1]->unsigned_flag;
-
-  if (Item_func_case_abbreviation2::result_type() == DECIMAL_RESULT ||
-      Item_func_case_abbreviation2::result_type() == INT_RESULT)
-  {
-    int len0= args[0]->max_char_length() - args[0]->decimals
-      - (args[0]->unsigned_flag ? 0 : 1);
-
-    int len1= args[1]->max_char_length() - args[1]->decimals
-      - (args[1]->unsigned_flag ? 0 : 1);
-
-    char_length= MY_MAX(len0, len1) + decimals + (unsigned_flag ? 0 : 1);
-  }
-  else
-    char_length= MY_MAX(args[0]->max_char_length(), args[1]->max_char_length());
-
-  switch (Item_func_case_abbreviation2::result_type()) {
-  case STRING_RESULT:
-    if (count_string_result_length(Item_func_case_abbreviation2::field_type(),
-                                   args, 2))
-      return;
-    break;
-  case DECIMAL_RESULT:
-  case REAL_RESULT:
-    break;
-  case INT_RESULT:
-    decimals= 0;
-    break;
-  case ROW_RESULT:
-  case TIME_RESULT:
-    DBUG_ASSERT(0);
-  }
-  fix_char_length(char_length);
-}
-
-
-
 uint Item_func_case_abbreviation2::decimal_precision2(Item **args) const
 {
   int arg0_int_part= args[0]->decimal_int_part();
@@ -3076,24 +3032,6 @@ bool Item_func_case::fix_fields(THD *thd, Item **ref)
 }
 
 
-void Item_func_case::agg_str_lengths(Item* arg)
-{
-  fix_char_length(MY_MAX(max_char_length(), arg->max_char_length()));
-  set_if_bigger(decimals, arg->decimals);
-  unsigned_flag= unsigned_flag && arg->unsigned_flag;
-}
-
-
-void Item_func_case::agg_num_lengths(Item *arg)
-{
-  uint len= my_decimal_length_to_precision(arg->max_length, arg->decimals,
-                                           arg->unsigned_flag) - arg->decimals;
-  set_if_bigger(max_length, len); 
-  set_if_bigger(decimals, arg->decimals);
-  unsigned_flag= unsigned_flag && arg->unsigned_flag; 
-}
-
-
 /**
   Check if (*place) and new_value points to different Items and call
   THD::change_item_tree() if needed.
@@ -3155,18 +3093,7 @@ void Item_func_case::fix_length_and_dec()
   }
   else
   {
-    collation.set_numeric();
-    max_length=0;
-    decimals=0;
-    unsigned_flag= TRUE;
-    for (uint i= 0; i < ncases; i+= 2)
-      agg_num_lengths(args[i + 1]);
-    if (else_expr_num != -1) 
-      agg_num_lengths(args[else_expr_num]);
-    max_length= my_decimal_precision_to_length_no_truncation(max_length +
-                                                             decimals,
-                                                             decimals,
-                                                             unsigned_flag);
+    fix_attributes(agg, nagg);
   }
 
   /*
@@ -3468,23 +3395,25 @@ my_decimal *Item_func_coalesce::decimal_op(my_decimal *decimal_value)
 }
 
 
-void Item_func_coalesce::fix_length_and_dec()
+void Item_hybrid_func::fix_attributes(Item **items, uint nitems)
 {
-  set_handler_by_field_type(agg_field_type(args, arg_count, true));
-  switch (Item_func_coalesce::result_type()) {
+  switch (Item_hybrid_func::result_type()) {
   case STRING_RESULT:
-    if (count_string_result_length(Item_func_coalesce::field_type(),
-                                   args, arg_count))
+    if (count_string_result_length(Item_hybrid_func::field_type(),
+                                   items, nitems))
       return;          
     break;
   case DECIMAL_RESULT:
-    count_decimal_length();
+    collation.set_numeric();
+    count_decimal_length(items, nitems);
     break;
   case REAL_RESULT:
-    count_real_length();
+    collation.set_numeric();
+    count_real_length(items, nitems);
     break;
   case INT_RESULT:
-    count_only_length(args, arg_count);
+    collation.set_numeric();
+    count_only_length(items, nitems);
     decimals= 0;
     break;
   case ROW_RESULT:

sql/item_cmpfunc.h

@@ -902,7 +902,11 @@ class Item_func_coalesce :public Item_func_hybrid_field_type
   String *str_op(String *);
   my_decimal *decimal_op(my_decimal *);
   bool date_op(MYSQL_TIME *ltime,uint fuzzydate);
-  void fix_length_and_dec();
+  void fix_length_and_dec()
+  {
+    set_handler_by_field_type(agg_field_type(args, arg_count, true));
+    fix_attributes(args, arg_count);
+  }
   const char *func_name() const { return "coalesce"; }
   table_map not_null_tables() const { return 0; }
 };
@@ -915,13 +919,18 @@ class Item_func_coalesce :public Item_func_hybrid_field_type
 */
 class Item_func_case_abbreviation2 :public Item_func_hybrid_field_type
 {
+protected:
+  void fix_length_and_dec2(Item **items)
+  {
+    set_handler_by_field_type(agg_field_type(items, 2, true));
+    fix_attributes(items, 2);
+  }
+  uint decimal_precision2(Item **args) const;
 public:
   Item_func_case_abbreviation2(THD *thd, Item *a, Item *b):
     Item_func_hybrid_field_type(thd, a, b) { }
   Item_func_case_abbreviation2(THD *thd, Item *a, Item *b, Item *c):
     Item_func_hybrid_field_type(thd, a, b, c) { }
-  void fix_length_and_dec2(Item **args);
-  uint decimal_precision2(Item **args) const;
 };
 
 
@@ -1454,8 +1463,6 @@ class Item_func_case :public Item_func_hybrid_field_type
   Item *find_item(String *str);
   CHARSET_INFO *compare_collation() const { return cmp_collation.collation; }
   void cleanup();
-  void agg_str_lengths(Item *arg);
-  void agg_num_lengths(Item *arg);
   Item* propagate_equal_fields(THD *thd, const Context &ctx, COND_EQUAL *cond);
 };