Bug#55912 FORMAT with locale set fails for numbers < 1000

Problems:
- dot character was always printed as decimal point
  instead of localized decimal point for short
  numbers without thousands
- Item_func_format::val_str always returned values in ASCII
format,
  regargless of @@character_set_connection, which in case of utf32
  led to crash in debug build, or to incorrect values in release build.

Fix:
- Adding a piece of code to replace dot character to
  localized decimal point in short numbers.
- Changing parent class for Item_func_format to
  Item_str_ascii_func, because its val_str() implementation is heavily ASCII oriented.

mysql-test/r/ctype_utf32.result

@@ -1100,5 +1100,19 @@ my_col
 00
 DROP TABLE t1;
 #
+# Bug#55912 FORMAT with locale set fails for numbers < 1000
+#
+SET collation_connection=utf32_general_ci;
+CREATE TABLE t1 AS SELECT format(123,2,'no_NO');
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `format(123,2,'no_NO')` varchar(37) CHARACTER SET utf32 NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT * FROM t1;
+format(123,2,'no_NO')
+123,00
+DROP TABLE t1;
+#
 # End of 5.5 tests
 #

mysql-test/r/func_str.result

@@ -2734,3 +2734,28 @@ format(123, 1, 'Non-existent-locale')
 Warnings:
 Warning	1649	Unknown locale: 'Non-existent-locale'
 End of 5.4 tests
+#
+# Start of 5.5 tests
+#
+#
+# Bug#55912 FORMAT with locale set fails for numbers < 1000
+#
+SELECT FORMAT(123.33, 2, 'no_NO'), FORMAT(1123.33, 2, 'no_NO');
+FORMAT(123.33, 2, 'no_NO')	FORMAT(1123.33, 2, 'no_NO')
+123,33	1.123,33
+SELECT FORMAT(12333e-2, 2, 'no_NO'), FORMAT(112333e-2, 2, 'no_NO');
+FORMAT(12333e-2, 2, 'no_NO')	FORMAT(112333e-2, 2, 'no_NO')
+123,33	1.123,33
+CREATE TABLE t1 AS SELECT format(123,2,'no_NO');
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `format(123,2,'no_NO')` varchar(37) NOT NULL DEFAULT ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+SELECT * FROM t1;
+format(123,2,'no_NO')
+123,00
+DROP TABLE t1;
+#
+# End of 5.5 tests
+#

mysql-test/t/ctype_utf32.test

@@ -809,6 +809,15 @@ CREATE TABLE t1 AS SELECT HEX(0x00) AS my_col;
 SELECT * FROM t1;
 DROP TABLE t1;
 
+--echo #
+--echo # Bug#55912 FORMAT with locale set fails for numbers < 1000
+--echo #
+SET collation_connection=utf32_general_ci;
+CREATE TABLE t1 AS SELECT format(123,2,'no_NO');
+SHOW CREATE TABLE t1;
+SELECT * FROM t1;
+DROP TABLE t1;
+
 --echo #
 --echo # End of 5.5 tests
 --echo #

mysql-test/t/func_str.test

@@ -1404,3 +1404,20 @@ SELECT format(123, 1, 'Non-existent-locale');
 
 --echo End of 5.4 tests
 
+--echo #
+--echo # Start of 5.5 tests
+--echo #
+
+--echo #
+--echo # Bug#55912 FORMAT with locale set fails for numbers < 1000
+--echo #
+SELECT FORMAT(123.33, 2, 'no_NO'), FORMAT(1123.33, 2, 'no_NO');
+SELECT FORMAT(12333e-2, 2, 'no_NO'), FORMAT(112333e-2, 2, 'no_NO');
+CREATE TABLE t1 AS SELECT format(123,2,'no_NO');
+SHOW CREATE TABLE t1;
+SELECT * FROM t1;
+DROP TABLE t1;
+
+--echo #
+--echo # End of 5.5 tests
+--echo #

sql/item_strfunc.cc

@@ -2217,7 +2217,7 @@ const int FORMAT_MAX_DECIMALS= 30;
 MY_LOCALE *Item_func_format::get_locale(Item *item)
 {
   DBUG_ASSERT(arg_count == 3);
-  String tmp, *locale_name= args[2]->val_str(&tmp);
+  String tmp, *locale_name= args[2]->val_str_ascii(&tmp);
   MY_LOCALE *lc;
   if (!locale_name ||
       !(lc= my_locale_by_name(locale_name->c_ptr_safe())))
@@ -2250,7 +2250,7 @@ void Item_func_format::fix_length_and_dec()
   are stored in more than one byte
 */
 
-String *Item_func_format::val_str(String *str)
+String *Item_func_format::val_str_ascii(String *str)
 {
   uint32 str_length;
   /* Number of decimal digits */
@@ -2290,8 +2290,7 @@ String *Item_func_format::val_str(String *str)
     if ((null_value=args[0]->null_value))
       return 0; /* purecov: inspected */
     nr= my_double_round(nr, (longlong) dec, FALSE, FALSE);
-    /* Here default_charset() is right as this is not an automatic conversion */
+    str->set_real(nr, dec, &my_charset_numeric);
-    str->set_real(nr, dec, default_charset());
     if (isnan(nr))
       return str;
     str_length=str->length();
@@ -2341,6 +2340,14 @@ String *Item_func_format::val_str(String *str)
     /* Put the rest of the integer part without grouping */
     str->copy(dst, buf + sizeof(buf) - dst, &my_charset_latin1);
   }
+  else if (dec_length && lc->decimal_point != '.')
+  {
+    /*
+      For short values without thousands (<1000)
+      replace decimal point to localized value.
+    */
+    ((char*) str->ptr())[str_length - dec_length]= lc->decimal_point;
+  }
   return str;
 }
 

sql/item_strfunc.h

@@ -539,17 +539,17 @@ public:
 };
 
 
-class Item_func_format :public Item_str_func
+class Item_func_format :public Item_str_ascii_func
 {
   String tmp_str;
   MY_LOCALE *locale;
 public:
-  Item_func_format(Item *org, Item *dec): Item_str_func(org, dec) {}
+  Item_func_format(Item *org, Item *dec): Item_str_ascii_func(org, dec) {}
   Item_func_format(Item *org, Item *dec, Item *lang):
-  Item_str_func(org, dec, lang) {}
+  Item_str_ascii_func(org, dec, lang) {}
   
   MY_LOCALE *get_locale(Item *item);
-  String *val_str(String *);
+  String *val_str_ascii(String *);
   void fix_length_and_dec();
   const char *func_name() const { return "format"; }
   virtual void print(String *str, enum_query_type query_type);