Bug#35924 DEFINER should be stored 'quoted' in I_S

The '@' symbol can not be used in the host name according to rfc952.
The fix:
added function check_host_name(LEX_STRING *str)
which checks that all symbols in host name string are valid and
host name length is not more than max host name length
(just moved check_string_length() function from the parser into check_host_name()).


mysql-test/r/create.result:
  test result
mysql-test/t/create.test:
  test case
sql/mysql_priv.h:
  added function check_host_name(LEX_STRING *str)
sql/sql_parse.cc:
  added function check_host_name(LEX_STRING *str)
  which checks that all symbols in host name string are valid and
  host name length is not more than max host name length(HOSTNAME_LENGTH).
sql/sql_yacc.yy:
  using newly added function check_host_name()

1 files changed, 32 insertions, 0 deletions

diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 83b111b7c4c..713aca9de47 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -7982,3 +7982,35 @@ int test_if_data_home_dir(const char *dir)
 
 C_MODE_END
 
+
+/**
+  Check that host name string is valid.
+
+  @param[in] str string to be checked
+
+  @return             Operation status
+    @retval  FALSE    host name is ok
+    @retval  TRUE     host name string is longer than max_length or
+                      has invalid symbols
+*/
+
+bool check_host_name(LEX_STRING *str)
+{
+  const char *name= str->str;
+  const char *end= str->str + str->length;
+  if (check_string_length(str, ER(ER_HOSTNAME), HOSTNAME_LENGTH))
+    return TRUE;
+
+  while (name != end)
+  {
+    if (*name == '@')
+    {
+      my_printf_error(ER_UNKNOWN_ERROR, 
+                      "Malformed hostname (illegal symbol: '%c')", MYF(0),
+                      *name);
+      return TRUE;
+    }
+    name++;
+  }
+  return FALSE;
+}