Bug#12611: ESCAPE + LIKE do not work when the escape char is a multibyte one

item_cmpfunc.cc:
  Pass unicode value as "escape" argument to my_wildcmp
  if a multibyte character set is used.
  For single byte character set nothing has changed:
  native (non-unicode) character code is still passed.

ctype_utf8.result, ctype_utf8.test:
  adding test case

1 files changed, 19 insertions, 1 deletions

diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 9146b3c3b9e..c869e7f5c65 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -2293,7 +2293,25 @@ bool Item_func_like::fix_fields(THD *thd, TABLE_LIST *tlist, Item ** ref)
   {
     /* If we are on execution stage */
     String *escape_str= escape_item->val_str(&tmp_value1);
-    escape= escape_str ? *(escape_str->ptr()) : '\\';
+    if (escape_str)
+    {
+      CHARSET_INFO *cs= cmp.cmp_collation.collation;
+      if (use_mb(cs))
+      {
+        my_wc_t wc;
+        int rc= cs->cset->mb_wc(cs, &wc,
+                                (const uchar*) escape_str->ptr(),
+                                (const uchar*) escape_str->ptr() +
+                                               escape_str->length());
+        escape= (int) (rc > 0 ? wc : '\\');
+      }
+      else
+      {
+        escape= *(escape_str->ptr());
+      }
+    }
+    else
+      escape= '\\';
  
     /*
       We could also do boyer-more for non-const items, but as we would have to