Adding MY_CHARSET_HANDLER::native_to_mb().

This is a pre-requisite patch for:
- MDEV-8433 Make field<'broken-string' use indexes
- MDEV-8625 Bad result set with ignorable characters when using a prefix key
- MDEV-8626 Bad result set with contractions when using a prefix key

1 files changed, 15 insertions, 0 deletions

diff --git a/include/m_ctype.h b/include/m_ctype.h
index 9db8fca12b3..c5be24bb063 100644
--- a/include/m_ctype.h
+++ b/include/m_ctype.h
@@ -511,6 +511,20 @@ struct my_charset_handler_st
                       char *dst, size_t dst_length,
                       const char *src, size_t src_length,
                       size_t nchars, MY_STRCOPY_STATUS *status);
+  /**
+    Write a character to the target string, using its native code.
+    For Unicode character sets (utf8, ucs2, utf16, utf16le, utf32, filename)
+    native codes are equvalent to Unicode code points.
+    For 8bit character sets the native code is just the byte value.
+    For Asian characters sets:
+    - MB1 native code is just the byte value (e.g. on the ASCII range)
+    - MB2 native code is ((b0 << 8) + b1).
+    - MB3 native code is ((b0 <<16) + (b1 << 8) + b2)
+    Note, CHARSET_INFO::min_sort_char and CHARSET_INFO::max_sort_char
+    are defined in native notation and should be written using
+    cs->cset->native_to_mb() rather than cs->cset->wc_mb().
+  */
+  my_charset_conv_wc_mb native_to_mb;
 };
 
 extern MY_CHARSET_HANDLER my_charset_8bit_handler;
@@ -664,6 +678,7 @@ extern int my_strcasecmp_8bit(CHARSET_INFO * cs, const char *, const char *);
 
 int my_mb_wc_8bit(CHARSET_INFO *cs,my_wc_t *wc, const uchar *s,const uchar *e);
 int my_wc_mb_8bit(CHARSET_INFO *cs,my_wc_t wc, uchar *s, uchar *e);
+int my_wc_mb_bin(CHARSET_INFO *cs,my_wc_t wc, uchar *s, uchar *e);
 
 int my_mb_ctype_8bit(CHARSET_INFO *,int *, const uchar *,const uchar *);
 int my_mb_ctype_mb(CHARSET_INFO *,int *, const uchar *,const uchar *);