MDEV-12658 Make the third parameter to LPAD and RPAD optional

mysql-test/t/func_str.test

@@ -119,6 +119,7 @@ select rpad('abcd',7,'ab'),lpad('abcd',7,'ab');
 select rpad('abcd',1,'ab'),lpad('abcd',1,'ab');
 select rpad('STRING', 20, CONCAT('p','a','d') );
 select lpad('STRING', 20, CONCAT('p','a','d') );
+select rpad('abcd',7),lpad('abcd',7);
 
 select LEAST(NULL,'HARRY','HARRIOT',NULL,'HAROLD'),GREATEST(NULL,'HARRY','HARRIOT',NULL,'HAROLD');
 select least(1,2,3) | greatest(16,32,8), least(5,4)*1,greatest(-1.0,1.0)*1,least(3,2,1)*1.0,greatest(1,1.1,1.0),least("10",9),greatest("A","B","0");
@@ -373,7 +374,9 @@ select collation(right(_latin2'a',1)), coercibility(right(_latin2'a',1));
 select collation(substring(_latin2'a',1,1)), coercibility(substring(_latin2'a',1,1));
 select collation(concat(_latin2'a',_latin2'b')), coercibility(concat(_latin2'a',_latin2'b'));
 select collation(lpad(_latin2'a',4,_latin2'b')), coercibility(lpad(_latin2'a',4,_latin2'b'));
+select collation(lpad(_latin2'a',4)), coercibility(lpad(_latin2'a',4));
 select collation(rpad(_latin2'a',4,_latin2'b')), coercibility(rpad(_latin2'a',4,_latin2'b'));
+select collation(rpad(_latin2'a',4)), coercibility(rpad(_latin2'a',4));
 select collation(concat_ws(_latin2'a',_latin2'b')), coercibility(concat_ws(_latin2'a',_latin2'b'));
 select collation(make_set(255,_latin2'a',_latin2'b',_latin2'c')), coercibility(make_set(255,_latin2'a',_latin2'b',_latin2'c'));
 select collation(export_set(255,_latin2'y',_latin2'n',_latin2' ')), coercibility(export_set(255,_latin2'y',_latin2'n',_latin2' '));
@@ -408,6 +411,8 @@ select
   concat(_latin2'a',_latin2'b'),
   lpad(_latin2'a',4,_latin2'b'),
   rpad(_latin2'a',4,_latin2'b'),
+  lpad(_latin2'a',4),
+  rpad(_latin2'a',4),
   concat_ws(_latin2'a',_latin2'b'),
   make_set(255,_latin2'a',_latin2'b',_latin2'c'),
   export_set(255,_latin2'y',_latin2'n',_latin2' '),
@@ -485,6 +490,8 @@ explain extended select concat('*',space(5),'*');
 explain extended select reverse('abc');
 explain extended select rpad('a',4,'1');
 explain extended select lpad('a',4,'1');
+explain extended select rpad('a',4);
+explain extended select lpad('a',4);
 explain extended select concat_ws(',','',NULL,'a');
 explain extended select make_set(255,_latin2'a', _latin2'b', _latin2'c');
 explain extended select elt(2,1);
@@ -1105,6 +1112,21 @@ select rpad('hello', -18446744073709551616, '1');
 select rpad('hello', 18446744073709551616, '1');
 select rpad('hello', -18446744073709551617, '1');
 select rpad('hello', 18446744073709551617, '1');
+select rpad('hello', -1);
+select rpad('hello', -4294967295);
+select rpad('hello', 4294967295);
+select rpad('hello', -4294967296);
+select rpad('hello', 4294967296);
+select rpad('hello', -4294967297);
+select rpad('hello', 4294967297);
+select rpad('hello', -18446744073709551615);
+select rpad('hello', 18446744073709551615);
+select rpad('hello', -18446744073709551616);
+select rpad('hello', 18446744073709551616);
+select rpad('hello', -18446744073709551617);
+select rpad('hello', 18446744073709551617);
+select rpad('hello', 0, 'x');
+select rpad('hello', 0);
 
 select lpad('hello', -1, '1');
 select lpad('hello', -4294967295, '1');
@@ -1119,7 +1141,32 @@ select lpad('hello', -18446744073709551616, '1');
 select lpad('hello', 18446744073709551616, '1');
 select lpad('hello', -18446744073709551617, '1');
 select lpad('hello', 18446744073709551617, '1');
-
+select lpad('hello', -1);
+select lpad('hello', -4294967295);
+select lpad('hello', 4294967295);
+select lpad('hello', -4294967296);
+select lpad('hello', 4294967296);
+select lpad('hello', -4294967297);
+select lpad('hello', 4294967297);
+select lpad('hello', -18446744073709551615);
+select lpad('hello', 18446744073709551615);
+select lpad('hello', -18446744073709551616);
+select lpad('hello', 18446744073709551616);
+select lpad('hello', -18446744073709551617);
+select lpad('hello', 18446744073709551617);
+select lpad('hello', 0, 'x');
+select lpad('hello', 0);
+
+--echo Check parameters count rpad / lpad
+--error ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT
+select rpad('x');
+--error ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT
+select rpad('x',2,'.','z');
+
+--error ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT
+select lpad('x');
+--error ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT
+select lpad('x',2,'.','z');
 
 #
 # BUG#17047: CHAR() and IN() can return NULL without signaling NULL
@@ -1141,6 +1188,8 @@ select substring('abc', cast(2 as unsigned int));
 select repeat('a', cast(2 as unsigned int));
 select rpad('abc', cast(5 as unsigned integer), 'x');
 select lpad('abc', cast(5 as unsigned integer), 'x');
+select rpad('abc', cast(5 as unsigned integer));
+select lpad('abc', cast(5 as unsigned integer));
 
 #
 # Bug#15757: Wrong SUBSTRING() result when a tmp table was employed.
@@ -1403,6 +1452,8 @@ SELECT RIGHT('1', DAY(FROM_UNIXTIME(-1)));
 SELECT REPEAT('1', DAY(FROM_UNIXTIME(-1)));
 SELECT RPAD('hi', DAY(FROM_UNIXTIME(-1)),'?');
 SELECT LPAD('hi', DAY(FROM_UNIXTIME(-1)),'?');
+SELECT RPAD('hi', DAY(FROM_UNIXTIME(-1)));
+SELECT LPAD('hi', DAY(FROM_UNIXTIME(-1)));
 
 #
 # MDEV-4289 Assertion `0' fails in make_sortkey with GROUP_CONCAT, MAKE_SET, GROUP BY

sql/item_create.cc

@@ -2260,10 +2260,11 @@ class Create_func_log2 : public Create_func_arg1
 };
 
 
-class Create_func_lpad : public Create_func_arg3
+class Create_func_lpad : public Create_native_func
 {
 public:
-  virtual Item *create_3_arg(THD *thd, Item *arg1, Item *arg2, Item *arg3);
+  virtual Item *create_native(THD *thd, LEX_CSTRING *name,
+                              List<Item> *item_list);
 
   static Create_func_lpad s_singleton;
 
@@ -2686,10 +2687,11 @@ class Create_func_round : public Create_native_func
 };
 
 
-class Create_func_rpad : public Create_func_arg3
+class Create_func_rpad : public Create_native_func
 {
 public:
-  virtual Item *create_3_arg(THD *thd, Item *arg1, Item *arg2, Item *arg3);
+  virtual Item *create_native(THD *thd, LEX_CSTRING *name,
+                              List<Item> *item_list);
 
   static Create_func_rpad s_singleton;
 
@@ -5791,9 +5793,34 @@ Create_func_log2::create_1_arg(THD *thd, Item *arg1)
 Create_func_lpad Create_func_lpad::s_singleton;
 
 Item*
-Create_func_lpad::create_3_arg(THD *thd, Item *arg1, Item *arg2, Item *arg3)
+Create_func_lpad::create_native(THD *thd, LEX_CSTRING *name,
+                                List<Item> *item_list)
 {
-  return new (thd->mem_root) Item_func_lpad(thd, arg1, arg2, arg3);
+  Item *func= NULL;
+  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();
+    func= new (thd->mem_root) Item_func_lpad(thd, param_1, param_2);
+    break;
+  }
+  case 3:
+  {
+    Item *param_1= item_list->pop();
+    Item *param_2= item_list->pop();
+    Item *param_3= item_list->pop();
+    func= new (thd->mem_root) Item_func_lpad(thd, param_1, param_2, param_3);
+    break;
+  }
+  default:
+    my_error(ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT, MYF(0), name->str);
+    break;
+  }
+
+  return func;
 }
 
 
@@ -6253,9 +6280,34 @@ Create_func_round::create_native(THD *thd, LEX_CSTRING *name,
 Create_func_rpad Create_func_rpad::s_singleton;
 
 Item*
-Create_func_rpad::create_3_arg(THD *thd, Item *arg1, Item *arg2, Item *arg3)
+Create_func_rpad::create_native(THD *thd, LEX_CSTRING *name,
+                                List<Item> *item_list)
 {
-  return new (thd->mem_root) Item_func_rpad(thd, arg1, arg2, arg3);
+  Item *func= NULL;
+  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();
+    func= new (thd->mem_root) Item_func_rpad(thd, param_1, param_2);
+    break;
+  }
+  case 3:
+  {
+    Item *param_1= item_list->pop();
+    Item *param_2= item_list->pop();
+    Item *param_3= item_list->pop();
+    func= new (thd->mem_root) Item_func_rpad(thd, param_1, param_2, param_3);
+    break;
+  }
+  default:
+    my_error(ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT, MYF(0), name->str);
+    break;
+  }
+
+  return func;
 }
 
 

sql/item_strfunc.cc

@@ -3154,9 +3154,20 @@ String *Item_func_binlog_gtid_pos::val_str(String *str)
 
 void Item_func_pad::fix_length_and_dec()
 {
-  // Handle character set for args[0] and args[2].
-  if (agg_arg_charsets_for_string_result(collation, &args[0], 2, 2))
-    return;
+  if (arg_count == 3)
+  {
+    // Handle character set for args[0] and args[2].
+    if (agg_arg_charsets_for_string_result(collation, &args[0], 2, 2))
+      return;
+  }
+  else
+  {
+    if (agg_arg_charsets_for_string_result(collation, &args[0], 1, 1))
+      return;
+    pad_str.set_charset(collation.collation);
+    pad_str.append(" ", 1);
+  }
+
   if (args[1]->const_item())
   {
     ulonglong char_length= (ulonglong) args[1]->val_int();
@@ -3187,11 +3198,15 @@ String *Item_func_rpad::val_str(String *str)
   longlong count= args[1]->val_int();
   longlong byte_count;
   String *res= args[0]->val_str(str);
-  String *rpad= args[2]->val_str(&pad_str);
+  String *rpad= arg_count == 2 ? &pad_str : args[2]->val_str(&pad_str);
 
   if (!res || args[1]->null_value || !rpad || 
       ((count < 0) && !args[1]->unsigned_flag))
     goto err;
+
+  if (count == 0)
+    return make_empty_result();
+
   null_value=0;
   /* Assumes that the maximum length of a String is < INT_MAX32. */
   /* Set here so that rest of code sees out-of-bound value as such. */
@@ -3216,7 +3231,6 @@ String *Item_func_rpad::val_str(String *str)
     res->length(res->charpos((int) count));	// Shorten result if longer
     return (res);
   }
-  pad_char_length= rpad->numchars();
 
   byte_count= count * collation.collation->mbmaxlen;
   {
@@ -3230,8 +3244,15 @@ String *Item_func_rpad::val_str(String *str)
       goto err;
     }
   }
-  if (args[2]->null_value || !pad_char_length)
-    goto err;
+
+  if (arg_count == 3)
+  {
+    if (args[2]->null_value || !(pad_char_length= rpad->numchars()))
+      goto err;
+  }
+  else
+    pad_char_length= 1; // Implicit space
+
   res_byte_length= res->length();	/* Must be done before alloc_buffer */
   if (!(res= alloc_buffer(res,str,&tmp_value, (ulong) byte_count)))
     goto err;
@@ -3268,11 +3289,15 @@ String *Item_func_lpad::val_str(String *str)
   longlong count= args[1]->val_int();
   longlong byte_count;
   String *res= args[0]->val_str(&tmp_value);
-  String *pad= args[2]->val_str(&pad_str);
+  String *pad= arg_count == 2 ? &pad_str : args[2]->val_str(&pad_str);
 
   if (!res || args[1]->null_value || !pad ||  
       ((count < 0) && !args[1]->unsigned_flag))
     goto err;  
+
+  if (count == 0)
+    return make_empty_result();
+
   null_value=0;
   /* Assumes that the maximum length of a String is < INT_MAX32. */
   /* Set here so that rest of code sees out-of-bound value as such. */
@@ -3301,7 +3326,6 @@ String *Item_func_lpad::val_str(String *str)
     return res;
   }
   
-  pad_char_length= pad->numchars();
   byte_count= count * collation.collation->mbmaxlen;
   
   {
@@ -3316,9 +3340,16 @@ String *Item_func_lpad::val_str(String *str)
     }
   }
 
-  if (args[2]->null_value || !pad_char_length ||
-      str->alloc((uint32) byte_count))
+  if (str->alloc((uint32) byte_count))
     goto err;
+
+  if (arg_count == 3)
+  {
+    if (args[2]->null_value || !(pad_char_length= pad->numchars()))
+      goto err;
+  }
+  else
+    pad_char_length= 1; // Implicit space
   
   str->length(0);
   str->set_charset(collation.collation);

sql/item_strfunc.h

@@ -1010,6 +1010,8 @@ class Item_func_pad: public Item_str_func
 public:
   Item_func_pad(THD *thd, Item *arg1, Item *arg2, Item *arg3):
     Item_str_func(thd, arg1, arg2, arg3) {}
+  Item_func_pad(THD *thd, Item *arg1, Item *arg2):
+    Item_str_func(thd, arg1, arg2) {}
   void fix_length_and_dec();
 };
 
@@ -1019,6 +1021,8 @@ class Item_func_rpad :public Item_func_pad
 public:
   Item_func_rpad(THD *thd, Item *arg1, Item *arg2, Item *arg3):
     Item_func_pad(thd, arg1, arg2, arg3) {}
+  Item_func_rpad(THD *thd, Item *arg1, Item *arg2):
+    Item_func_pad(thd, arg1, arg2) {}
   String *val_str(String *);
   const char *func_name() const { return "rpad"; }
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
@@ -1031,6 +1035,8 @@ class Item_func_lpad :public Item_func_pad
 public:
   Item_func_lpad(THD *thd, Item *arg1, Item *arg2, Item *arg3):
     Item_func_pad(thd, arg1, arg2, arg3) {}
+  Item_func_lpad(THD *thd, Item *arg1, Item *arg2):
+    Item_func_pad(thd, arg1, arg2) {}
   String *val_str(String *);
   const char *func_name() const { return "lpad"; }
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)