Bug#21269 (DEFINER-clause is allowed for UDF-functions)

The problem was that the grammar allows to create a function with an optional
definer clause, and define it as a UDF with the SONAME keyword.
Such combination should be reported as an error.

The solution is to not change the grammar itself, and to introduce a
specific check in the yacc actions in 'create_function_tail' for UDF,
that now reports ER_WRONG_USAGE when using both DEFINER and SONAME.

mysql-test/r/udf.result

@@ -93,6 +93,12 @@ NULL
 0R
 FR
 DROP TABLE bug19904;
+CREATE DEFINER=CURRENT_USER() FUNCTION should_not_parse
+RETURNS STRING SONAME "should_not_parse.so";
+ERROR HY000: Incorrect usage of SONAME and DEFINER
+CREATE DEFINER=someone@somewhere FUNCTION should_not_parse
+RETURNS STRING SONAME "should_not_parse.so";
+ERROR HY000: Incorrect usage of SONAME and DEFINER
 End of 5.0 tests.
 DROP FUNCTION metaphon;
 DROP FUNCTION myfunc_double;

mysql-test/t/udf.test

@@ -109,6 +109,18 @@ SELECT myfunc_double(n) AS f FROM bug19904;
 SELECT metaphon(v) AS f FROM bug19904;
 DROP TABLE bug19904;
 
+#
+# Bug#21269: DEFINER-clause is allowed for UDF-functions
+#
+
+--error ER_WRONG_USAGE
+CREATE DEFINER=CURRENT_USER() FUNCTION should_not_parse
+RETURNS STRING SONAME "should_not_parse.so";
+
+--error ER_WRONG_USAGE
+CREATE DEFINER=someone@somewhere FUNCTION should_not_parse
+RETURNS STRING SONAME "should_not_parse.so";
+
 --echo End of 5.0 tests.
 
 #

sql/sql_yacc.yy

@@ -1256,6 +1256,17 @@ create_function_tail:
 	  RETURNS_SYM udf_type UDF_SONAME_SYM TEXT_STRING_sys
 	  {
 	    LEX *lex=Lex;
+            if (lex->definer != NULL)
+            {
+              /*
+                 DEFINER is a concept meaningful when interpreting SQL code.
+                 UDF functions are compiled.
+                 Using DEFINER with UDF has therefore no semantic,
+                 and is considered a parsing error.
+              */
+	      my_error(ER_WRONG_USAGE, MYF(0), "SONAME", "DEFINER");
+              YYABORT;
+            }
 	    lex->sql_command = SQLCOM_CREATE_FUNCTION;
 	    lex->udf.name = lex->spname->m_name;
 	    lex->udf.returns=(Item_result) $2;