MDEV-4842 STR_TO_DATE does not work with UCS2/UTF16/UTF32

4 files changed, 42 insertions, 4 deletions

diff --git a/sql/item.cc b/sql/item.cc
index 803c9fee576..a415464a2f9 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -218,6 +218,24 @@ bool Item::val_bool()
 }
 
 
+String *Item::val_str(String *str, String *converter, CHARSET_INFO *cs)
+{
+  String *res= val_str(str);
+  if (null_value)
+    return (String *) 0;
+
+  if (!cs)
+    return res;
+
+  uint errors;
+  if ((null_value= converter->copy(res->ptr(), res->length(),
+                                   collation.collation, cs,  &errors)))
+    return (String *) 0;
+
+  return converter;
+}
+
+
 String *Item::val_string_from_real(String *str)
 {
   double nr= val_real();
diff --git a/sql/item.h b/sql/item.h
index 4f03d588bbc..084e77e4d23 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -794,6 +794,10 @@ public:
   */
   virtual String *val_str(String *str)=0;
   /*
+    Returns the val_str() value converted to the given character set.
+  */
+  String *val_str(String *str, String *converter, CHARSET_INFO *to);
+  /*
     Return decimal representation of item with fixed point.
 
     SYNOPSIS
diff --git a/sql/item_timefunc.cc b/sql/item_timefunc.cc
index 6c304946abc..cb60368aafd 100644
--- a/sql/item_timefunc.cc
+++ b/sql/item_timefunc.cc
@@ -2980,13 +2980,25 @@ get_date_time_result_type(const char *format, uint length)
 
 void Item_func_str_to_date::fix_length_and_dec()
 {
+  if (agg_arg_charsets(collation, args, 2, MY_COLL_ALLOW_CONV, 1))
+    return;
+  if (collation.collation->mbminlen > 1)
+  {
+#if MYSQL_VERSION_ID > 50500
+    internal_charset= &my_charset_utf8mb4_general_ci;
+#else
+    internal_charset= &my_charset_utf8_general_ci;
+#endif
+  }
+
   cached_field_type= MYSQL_TYPE_DATETIME;
   decimals= NOT_FIXED_DEC;
   if ((const_item= args[1]->const_item()))
   {
     char format_buff[64];
     String format_str(format_buff, sizeof(format_buff), &my_charset_bin);
-    String *format= args[1]->val_str(&format_str);
+    String *format= args[1]->val_str(&format_str, &format_converter,
+                                     internal_charset);
     decimals= 0;
     if (!args[1]->null_value)
     {
@@ -3024,8 +3036,8 @@ bool Item_func_str_to_date::get_date(MYSQL_TIME *ltime, uint fuzzy_date)
   String format_str(format_buff, sizeof(format_buff), &my_charset_bin),
     *format;
 
-  val=    args[0]->val_str(&val_string);
-  format= args[1]->val_str(&format_str);
+  val=    args[0]->val_str(&val_string, &subject_converter, internal_charset);
+  format= args[1]->val_str(&format_str, &format_converter, internal_charset);
   if (args[0]->null_value || args[1]->null_value)
     goto null_date;
 
diff --git a/sql/item_timefunc.h b/sql/item_timefunc.h
index 20365d4f25d..bc048e1ff64 100644
--- a/sql/item_timefunc.h
+++ b/sql/item_timefunc.h
@@ -998,9 +998,13 @@ class Item_func_str_to_date :public Item_temporal_func
   enum_field_types cached_field_type;
   timestamp_type cached_timestamp_type;
   bool const_item;
+  String subject_converter;
+  String format_converter;
+  CHARSET_INFO *internal_charset;
 public:
   Item_func_str_to_date(Item *a, Item *b)
-    :Item_temporal_func(a, b), const_item(false)
+    :Item_temporal_func(a, b), const_item(false),
+    internal_charset(NULL)
   {}
   bool get_date(MYSQL_TIME *ltime, uint fuzzy_date);
   const char *func_name() const { return "str_to_date"; }