MDEV-15739 sql_mode=ORACLE: Make LPAD and RPAD return NULL instead of empty string

4 files changed, 246 insertions, 8 deletions

diff --git a/mysql-test/suite/compat/oracle/r/func_pad.result b/mysql-test/suite/compat/oracle/r/func_pad.result
new file mode 100644
index 00000000000..ca7d52cd542
--- /dev/null
+++ b/mysql-test/suite/compat/oracle/r/func_pad.result
@@ -0,0 +1,71 @@
+SET sql_mode=ORACLE;
+#
+# MDEV-15739 -  sql_mode=ORACLE: Make LPAD and RPAD return NULL instead of empty string
+#
+SELECT RPAD('a',0), RPAD('abc',1), RPAD('abc',2) ;
+RPAD('a',0)	RPAD('abc',1)	RPAD('abc',2)
+NULL	a	ab
+SELECT RPAD('a',0,'.'), RPAD('abc',1,'.'), RPAD('abc',2,'.') ;
+RPAD('a',0,'.')	RPAD('abc',1,'.')	RPAD('abc',2,'.')
+NULL	a	ab
+SELECT LPAD('a',0), LPAD('abc',1), LPAD('abc',2) ;
+LPAD('a',0)	LPAD('abc',1)	LPAD('abc',2)
+NULL	a	ab
+SELECT LPAD('a',0,'.'), LPAD('abc',1,'.'), LPAD('abc',2,'.') ;
+LPAD('a',0,'.')	LPAD('abc',1,'.')	LPAD('abc',2,'.')
+NULL	a	ab
+CREATE TABLE t1 (c1 VARCHAR(10),c2 INTEGER, c3 VARCHAR(10), ord INTEGER);
+INSERT INTO t1 VALUES ('a',1,null,1);
+INSERT INTO t1 VALUES ('a',null,'.',2);
+INSERT INTO t1 VALUES (null,1,'.',3);
+INSERT INTO t1 VALUES ('a',-1,'.',4);
+INSERT INTO t1 VALUES ('a',0,'.',5);
+INSERT INTO t1 VALUES ('a',1,'.',6);
+INSERT INTO t1 VALUES ('a',2,'.',7);
+SELECT LPAD(c1,c2,c3), LPAD(c1,c2) FROM t1 ORDER BY ord;
+LPAD(c1,c2,c3)	LPAD(c1,c2)
+NULL	a
+NULL	NULL
+NULL	NULL
+NULL	NULL
+NULL	NULL
+a	a
+.a	 a
+SELECT RPAD(c1,c2,c3), RPAD(c1,c2) FROM t1 ORDER BY ord;
+RPAD(c1,c2,c3)	RPAD(c1,c2)
+NULL	a
+NULL	NULL
+NULL	NULL
+NULL	NULL
+NULL	NULL
+a	a
+a.	a 
+EXPLAIN EXTENDED SELECT RPAD('a',0,'.'), LPAD('a',0,'.'), LPAD(c1,c2,c3), LPAD(c1,c2), RPAD(c1,c2,c3), RPAD(c1,c2) FROM t1 ORDER BY ord;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	7	100.00	Using filesort
+Warnings:
+Note	1003	select rpad_oracle('a',0,'.') AS "RPAD('a',0,'.')",lpad_oracle('a',0,'.') AS "LPAD('a',0,'.')",lpad_oracle("test"."t1"."c1","test"."t1"."c2","test"."t1"."c3") AS "LPAD(c1,c2,c3)",lpad_oracle("test"."t1"."c1","test"."t1"."c2") AS "LPAD(c1,c2)",rpad_oracle("test"."t1"."c1","test"."t1"."c2","test"."t1"."c3") AS "RPAD(c1,c2,c3)",rpad_oracle("test"."t1"."c1","test"."t1"."c2") AS "RPAD(c1,c2)" from "test"."t1" order by "test"."t1"."ord"
+CREATE VIEW v1 AS SELECT RPAD('a',0,'.') AS "C1", LPAD('a',0,'.') AS "C2", LPAD(c1,c2,c3) AS "C3", LPAD(c1,c2) AS "C4", RPAD(c1,c2,c3) AS "C5", RPAD(c1,c2) AS "C6" FROM t1 ORDER BY ord;
+SHOW CREATE VIEW v1;
+View	Create View	character_set_client	collation_connection
+v1	CREATE VIEW "v1" AS select rpad_oracle('a',0,'.') AS "C1",lpad_oracle('a',0,'.') AS "C2",lpad_oracle("t1"."c1","t1"."c2","t1"."c3") AS "C3",lpad_oracle("t1"."c1","t1"."c2") AS "C4",rpad_oracle("t1"."c1","t1"."c2","t1"."c3") AS "C5",rpad_oracle("t1"."c1","t1"."c2") AS "C6" from "t1" order by "t1"."ord"	latin1	latin1_swedish_ci
+SELECT * FROM v1;
+C1	C2	C3	C4	C5	C6
+NULL	NULL	NULL	a	NULL	a
+NULL	NULL	NULL	NULL	NULL	NULL
+NULL	NULL	NULL	NULL	NULL	NULL
+NULL	NULL	NULL	NULL	NULL	NULL
+NULL	NULL	NULL	NULL	NULL	NULL
+NULL	NULL	a	a	a	a
+NULL	NULL	.a	 a	a.	a 
+SELECT c1||'-'||c2||'-'||c3||'-'||c4||'-'||c5||'-'||c6 FROM v1;
+c1||'-'||c2||'-'||c3||'-'||c4||'-'||c5||'-'||c6
+---a--a
+-----
+-----
+-----
+-----
+--a-a-a-a
+--.a- a-a.-a 
+DROP VIEW v1;
+DROP TABLE t1;
diff --git a/mysql-test/suite/compat/oracle/t/func_pad.test b/mysql-test/suite/compat/oracle/t/func_pad.test
new file mode 100644
index 00000000000..bc33a9fa4f8
--- /dev/null
+++ b/mysql-test/suite/compat/oracle/t/func_pad.test
@@ -0,0 +1,31 @@
+SET sql_mode=ORACLE;
+
+--echo #
+--echo # MDEV-15739 -  sql_mode=ORACLE: Make LPAD and RPAD return NULL instead of empty string
+--echo #
+
+SELECT RPAD('a',0), RPAD('abc',1), RPAD('abc',2) ;
+SELECT RPAD('a',0,'.'), RPAD('abc',1,'.'), RPAD('abc',2,'.') ;
+SELECT LPAD('a',0), LPAD('abc',1), LPAD('abc',2) ;
+SELECT LPAD('a',0,'.'), LPAD('abc',1,'.'), LPAD('abc',2,'.') ;
+
+CREATE TABLE t1 (c1 VARCHAR(10),c2 INTEGER, c3 VARCHAR(10), ord INTEGER);
+INSERT INTO t1 VALUES ('a',1,null,1);
+INSERT INTO t1 VALUES ('a',null,'.',2);
+INSERT INTO t1 VALUES (null,1,'.',3);
+INSERT INTO t1 VALUES ('a',-1,'.',4);
+INSERT INTO t1 VALUES ('a',0,'.',5);
+INSERT INTO t1 VALUES ('a',1,'.',6);
+INSERT INTO t1 VALUES ('a',2,'.',7);
+
+SELECT LPAD(c1,c2,c3), LPAD(c1,c2) FROM t1 ORDER BY ord;
+SELECT RPAD(c1,c2,c3), RPAD(c1,c2) FROM t1 ORDER BY ord;
+
+EXPLAIN EXTENDED SELECT RPAD('a',0,'.'), LPAD('a',0,'.'), LPAD(c1,c2,c3), LPAD(c1,c2), RPAD(c1,c2,c3), RPAD(c1,c2) FROM t1 ORDER BY ord;
+
+CREATE VIEW v1 AS SELECT RPAD('a',0,'.') AS "C1", LPAD('a',0,'.') AS "C2", LPAD(c1,c2,c3) AS "C3", LPAD(c1,c2) AS "C4", RPAD(c1,c2,c3) AS "C5", RPAD(c1,c2) AS "C6" FROM t1 ORDER BY ord;
+SHOW CREATE VIEW v1;
+SELECT * FROM v1;
+SELECT c1||'-'||c2||'-'||c3||'-'||c4||'-'||c5||'-'||c6 FROM v1;
+DROP VIEW v1;
+DROP TABLE t1;
diff --git a/sql/item_create.cc b/sql/item_create.cc
index a07e4c9c16b..901dfa06f40 100644
--- a/sql/item_create.cc
+++ b/sql/item_create.cc
@@ -2195,13 +2195,30 @@ class Create_func_lpad : public Create_native_func
 {
 public:
   virtual Item *create_native(THD *thd, LEX_CSTRING *name,
-                              List<Item> *item_list);
-
+                              List<Item> *item_list)
+  {
+    return thd->variables.sql_mode & MODE_ORACLE ?
+           create_native_oracle(thd, name, item_list) :
+           create_native_std(thd, name, item_list);
+  }
   static Create_func_lpad s_singleton;
 
 protected:
   Create_func_lpad() {}
   virtual ~Create_func_lpad() {}
+  Item *create_native_std(THD *thd, LEX_CSTRING *name, List<Item> *items);
+  Item *create_native_oracle(THD *thd, LEX_CSTRING *name, List<Item> *items);
+};
+
+
+class Create_func_lpad_oracle : public Create_func_lpad
+{
+public:
+  Item *create_native(THD *thd, LEX_CSTRING *name, List<Item> *item_list)
+  {
+    return create_native_oracle(thd, name, item_list);
+  }
+  static Create_func_lpad_oracle s_singleton;
 };
 
 
@@ -2648,13 +2665,30 @@ class Create_func_rpad : public Create_native_func
 {
 public:
   virtual Item *create_native(THD *thd, LEX_CSTRING *name,
-                              List<Item> *item_list);
-
+                              List<Item> *item_list)
+  {
+    return thd->variables.sql_mode & MODE_ORACLE ?
+           create_native_oracle(thd, name, item_list) :
+           create_native_std(thd, name, item_list);
+  }
   static Create_func_rpad s_singleton;
 
 protected:
   Create_func_rpad() {}
   virtual ~Create_func_rpad() {}
+  Item *create_native_std(THD *thd, LEX_CSTRING *name, List<Item> *items);
+  Item *create_native_oracle(THD *thd, LEX_CSTRING *name, List<Item> *items);
+};
+
+
+class Create_func_rpad_oracle : public Create_func_rpad
+{
+public:
+  Item *create_native(THD *thd, LEX_CSTRING *name, List<Item> *item_list)
+  {
+    return create_native_oracle(thd, name, item_list);
+  }
+  static Create_func_rpad_oracle s_singleton;
 };
 
 
@@ -5810,9 +5844,11 @@ Create_func_log2::create_1_arg(THD *thd, Item *arg1)
 
 Create_func_lpad Create_func_lpad::s_singleton;
 
+Create_func_lpad_oracle Create_func_lpad_oracle::s_singleton;
+
 Item*
-Create_func_lpad::create_native(THD *thd, LEX_CSTRING *name,
-                                List<Item> *item_list)
+Create_func_lpad::create_native_std(THD *thd, LEX_CSTRING *name,
+                                    List<Item> *item_list)
 {
   Item *func= NULL;
   int arg_count= item_list ? item_list->elements : 0;
@@ -5842,6 +5878,34 @@ Create_func_lpad::create_native(THD *thd, LEX_CSTRING *name,
 }
 
 
+Item*
+Create_func_lpad::create_native_oracle(THD *thd, LEX_CSTRING *name,
+                                       List<Item> *item_list)
+{
+  int arg_count= item_list ? item_list->elements : 0;
+  switch (arg_count) {
+  case 2:
+  {
+    Item *param_1= item_list->pop();
+    Item *param_2= item_list->pop();
+    return new (thd->mem_root) Item_func_lpad_oracle(thd, param_1, param_2);
+  }
+  case 3:
+  {
+    Item *param_1= item_list->pop();
+    Item *param_2= item_list->pop();
+    Item *param_3= item_list->pop();
+    return new (thd->mem_root) Item_func_lpad_oracle(thd, param_1,
+                                                     param_2, param_3);
+  }
+  default:
+    my_error(ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT, MYF(0), name->str);
+    break;
+  }
+  return NULL;
+}
+
+
 Create_func_ltrim Create_func_ltrim::s_singleton;
 
 Item*
@@ -6316,9 +6380,11 @@ Create_func_round::create_native(THD *thd, LEX_CSTRING *name,
 
 Create_func_rpad Create_func_rpad::s_singleton;
 
+Create_func_rpad_oracle Create_func_rpad_oracle::s_singleton;
+
 Item*
-Create_func_rpad::create_native(THD *thd, LEX_CSTRING *name,
-                                List<Item> *item_list)
+Create_func_rpad::create_native_std(THD *thd, LEX_CSTRING *name,
+                                    List<Item> *item_list)
 {
   Item *func= NULL;
   int arg_count= item_list ? item_list->elements : 0;
@@ -6348,6 +6414,34 @@ Create_func_rpad::create_native(THD *thd, LEX_CSTRING *name,
 }
 
 
+Item*
+Create_func_rpad::create_native_oracle(THD *thd, LEX_CSTRING *name,
+                                       List<Item> *item_list)
+{
+  int arg_count= item_list ? item_list->elements : 0;
+  switch (arg_count) {
+  case 2:
+  {
+    Item *param_1= item_list->pop();
+    Item *param_2= item_list->pop();
+    return new (thd->mem_root) Item_func_rpad_oracle(thd, param_1, param_2);
+  }
+  case 3:
+  {
+    Item *param_1= item_list->pop();
+    Item *param_2= item_list->pop();
+    Item *param_3= item_list->pop();
+    return new (thd->mem_root) Item_func_rpad_oracle(thd, param_1,
+                                                     param_2, param_3);
+  }
+  default:
+    my_error(ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT, MYF(0), name->str);
+    break;
+  }
+  return NULL;
+}
+
+
 Create_func_rtrim Create_func_rtrim::s_singleton;
 
 Item*
@@ -7021,6 +7115,7 @@ static Native_func_registry func_array[] =
   { { STRING_WITH_LEN("LOG2") }, BUILDER(Create_func_log2)},
   { { STRING_WITH_LEN("LOWER") }, BUILDER(Create_func_lcase)},
   { { STRING_WITH_LEN("LPAD") }, BUILDER(Create_func_lpad)},
+  { { STRING_WITH_LEN("LPAD_ORACLE") }, BUILDER(Create_func_lpad_oracle)},
   { { STRING_WITH_LEN("LTRIM") }, BUILDER(Create_func_ltrim)},
   { { STRING_WITH_LEN("LTRIM_ORACLE") }, BUILDER(Create_func_ltrim_oracle)},
   { { STRING_WITH_LEN("MAKEDATE") }, BUILDER(Create_func_makedate)},
@@ -7086,6 +7181,7 @@ static Native_func_registry func_array[] =
   { { STRING_WITH_LEN("REVERSE") }, BUILDER(Create_func_reverse)},
   { { STRING_WITH_LEN("ROUND") }, BUILDER(Create_func_round)},
   { { STRING_WITH_LEN("RPAD") }, BUILDER(Create_func_rpad)},
+  { { STRING_WITH_LEN("RPAD_ORACLE") }, BUILDER(Create_func_rpad_oracle)},
   { { STRING_WITH_LEN("RTRIM") }, BUILDER(Create_func_rtrim)},
   { { STRING_WITH_LEN("RTRIM_ORACLE") }, BUILDER(Create_func_rtrim_oracle)},
   { { STRING_WITH_LEN("SEC_TO_TIME") }, BUILDER(Create_func_sec_to_time)},
diff --git a/sql/item_strfunc.h b/sql/item_strfunc.h
index 4e1514c5476..18cda491efd 100644
--- a/sql/item_strfunc.h
+++ b/sql/item_strfunc.h
@@ -1120,6 +1120,26 @@ public:
 };
 
 
+class Item_func_rpad_oracle :public Item_func_rpad
+{
+  String *make_empty_result()
+  { null_value= 1; return NULL; }
+public:
+  Item_func_rpad_oracle(THD *thd, Item *arg1, Item *arg2, Item *arg3):
+    Item_func_rpad(thd, arg1, arg2, arg3) {}
+  Item_func_rpad_oracle(THD *thd, Item *arg1, Item *arg2):
+    Item_func_rpad(thd, arg1, arg2) {}
+  void fix_length_and_dec()
+  {
+    Item_func_rpad::fix_length_and_dec();
+    maybe_null= true;
+  }
+  const char *func_name() const { return "rpad_oracle"; }
+  Item *get_copy(THD *thd)
+  { return get_item_copy<Item_func_rpad_oracle>(thd, this); }
+};
+
+
 class Item_func_lpad :public Item_func_pad
 {
 public:
@@ -1134,6 +1154,26 @@ public:
 };
 
 
+class Item_func_lpad_oracle :public Item_func_lpad
+{
+  String *make_empty_result()
+  { null_value= 1; return NULL; }
+public:
+  Item_func_lpad_oracle(THD *thd, Item *arg1, Item *arg2, Item *arg3):
+    Item_func_lpad(thd, arg1, arg2, arg3) {}
+  Item_func_lpad_oracle(THD *thd, Item *arg1, Item *arg2):
+    Item_func_lpad(thd, arg1, arg2) {}
+  void fix_length_and_dec()
+  {
+    Item_func_lpad::fix_length_and_dec();
+    maybe_null= true;
+  }
+  const char *func_name() const { return "lpad_oracle"; }
+  Item *get_copy(THD *thd)
+  { return get_item_copy<Item_func_lpad_oracle>(thd, this); }
+};
+
+
 class Item_func_conv :public Item_str_func
 {
 public: