Bug #38159: Function parsing problem generates misleading error message

      
Added a more detailed error message on calling an ambiguous missing function.

mysql-test/r/ps.result

@@ -502,7 +502,7 @@ deallocate prepare stmt;
 create table t1 (a varchar(20));
 insert into t1 values ('foo');
 prepare stmt FROM 'SELECT char_length (a) FROM t1';
-ERROR 42000: FUNCTION test.char_length does not exist
+ERROR 42000: FUNCTION test.char_length does not exist. Check the 'Function Name Parsing and Resolution' section in the Reference Manual
 drop table t1;
 prepare stmt from "SELECT SQL_CALC_FOUND_ROWS 'foo' UNION SELECT 'bar' LIMIT 0";
 execute stmt;
@@ -1147,7 +1147,7 @@ End of 4.1 tests.
 create table t1 (a varchar(20));
 insert into t1 values ('foo');
 prepare stmt FROM 'SELECT char_length (a) FROM t1';
-ERROR 42000: FUNCTION test.char_length does not exist
+ERROR 42000: FUNCTION test.char_length does not exist. Check the 'Function Name Parsing and Resolution' section in the Reference Manual
 drop table t1;
 create table t1 (a char(3) not null, b char(3) not null,
 c char(3) not null, primary key  (a, b, c));

mysql-test/r/sp-error.result

@@ -1520,3 +1520,13 @@ CALL p1((SELECT * FROM t1))|
 ERROR 21000: Subquery returns more than 1 row
 DROP PROCEDURE IF EXISTS p1|
 DROP TABLE t1|
+CREATE TABLE t1 (a INT, b INT);
+INSERT INTO t1 VALUES (1,1), (2,2);
+SELECT MAX (a) FROM t1 WHERE b = 999999;
+ERROR 42000: FUNCTION test.MAX does not exist. Check the 'Function Name Parsing and Resolution' section in the Reference Manual
+SELECT AVG (a) FROM t1 WHERE b = 999999;
+AVG (a)
+NULL
+SELECT non_existent (a) FROM t1 WHERE b = 999999;
+ERROR 42000: FUNCTION test.non_existent does not exist
+DROP TABLE t1;

mysql-test/t/ps.test

@@ -530,7 +530,7 @@ deallocate prepare stmt;
 #
 create table t1 (a varchar(20)); 
 insert into t1 values ('foo'); 
---error 1305
+--error ER_FUNC_INEXISTENT_NAME_COLLISION
 prepare stmt FROM 'SELECT char_length (a) FROM t1'; 
 drop table t1;
 
@@ -1239,7 +1239,7 @@ drop table t1;
 #
 create table t1 (a varchar(20)); 
 insert into t1 values ('foo'); 
---error 1305
+--error ER_FUNC_INEXISTENT_NAME_COLLISION
 prepare stmt FROM 'SELECT char_length (a) FROM t1'; 
 drop table t1;
 

mysql-test/t/sp-error.test

@@ -2190,3 +2190,16 @@ delimiter ;|
 #drop procedure if exists bugNNNN|
 #--enable_warnings
 #create procedure bugNNNN...
+
+#
+# Bug #38159: Function parsing problem generates misleading error message
+#
+
+CREATE TABLE t1 (a INT, b INT);
+INSERT INTO t1 VALUES (1,1), (2,2);
+--error ER_FUNC_INEXISTENT_NAME_COLLISION
+SELECT MAX (a) FROM t1 WHERE b = 999999;
+SELECT AVG (a) FROM t1 WHERE b = 999999;
+--error ER_SP_DOES_NOT_EXIST
+SELECT non_existent (a) FROM t1 WHERE b = 999999;
+DROP TABLE t1;

sql/item_func.cc

@@ -5401,6 +5401,14 @@ Item_func_sp::func_name() const
 }
 
 
+int my_missing_function_error(const LEX_STRING &token, const char *func_name)
+{
+  if (token.length && is_lex_native_function (&token))
+    return my_error(ER_FUNC_INEXISTENT_NAME_COLLISION, MYF(0), func_name);
+  else
+    return my_error(ER_SP_DOES_NOT_EXIST, MYF(0), "FUNCTION", func_name);
+}
+
 
 /**
   @brief Initialize the result field by creating a temporary dummy table
@@ -5434,7 +5442,7 @@ Item_func_sp::init_result_field(THD *thd)
   if (!(m_sp= sp_find_routine(thd, TYPE_ENUM_FUNCTION, m_name,
                                &thd->sp_func_cache, TRUE)))
   {
-    my_error(ER_SP_DOES_NOT_EXIST, MYF(0), "FUNCTION", m_name->m_qname.str);
+    my_missing_function_error (m_name->m_name, m_name->m_qname.str);
     context->process_error(thd);
     DBUG_RETURN(TRUE);
   }

sql/share/errmsg.txt

@@ -5649,3 +5649,6 @@ ER_XA_RBTIMEOUT XA106
 	eng "XA_RBTIMEOUT: Transaction branch was rolled back: took too long"
 ER_XA_RBDEADLOCK XA102
 	eng "XA_RBDEADLOCK: Transaction branch was rolled back: deadlock was detected"
+
+ER_FUNC_INEXISTENT_NAME_COLLISION 42000 
+	eng "FUNCTION %s does not exist. Check the 'Function Name Parsing and Resolution' section in the Reference Manual"

sql/sql_derived.cc

@@ -148,6 +148,7 @@ exit:
     if (orig_table_list->view)
     {
       if (thd->net.last_errno == ER_BAD_FIELD_ERROR ||
+          thd->net.last_errno == ER_FUNC_INEXISTENT_NAME_COLLISION ||
           thd->net.last_errno == ER_SP_DOES_NOT_EXIST)
       {
         thd->clear_error();

sql/sql_lex.cc

@@ -265,6 +265,22 @@ bool is_keyword(const char *name, uint len)
   return get_hash_symbol(name,len,0)!=0;
 }
 
+/**
+  Check if name is a sql function
+
+    @param name      checked name
+
+    @return is this a lex native function or not
+    @retval 0         name is a function
+    @retval 1         name isn't a function
+*/
+
+bool is_lex_native_function(const LEX_STRING *name)
+{
+  DBUG_ASSERT(name != NULL);
+  return (get_hash_symbol(name->str, (uint) name->length, 1) != 0);
+}
+
 /* make a copy of token before ptr and set yytoklen */
 
 static LEX_STRING get_token(Lex_input_stream *lip, uint skip, uint length)

sql/sql_lex.h

@@ -1390,3 +1390,5 @@ extern void lex_end(LEX *lex);
 extern int MYSQLlex(void *arg, void *yythd);
 extern char *skip_rear_comments(CHARSET_INFO *cs, char *begin, char *end);
 
+extern bool is_lex_native_function(const LEX_STRING *name);
+int my_missing_function_error(const LEX_STRING &token, const char *name);

sql/sql_yacc.yy

@@ -5968,8 +5968,7 @@ simple_expr:
                   Reusing ER_SP_DOES_NOT_EXIST have a message consistent with
                   the case when a default database exist, see below.
                 */
-                my_error(ER_SP_DOES_NOT_EXIST, MYF(0),
-                         "FUNCTION", $1.str);
+                my_missing_function_error ($1, $1.str);
                 MYSQL_YYABORT;
               }
               

sql/table.cc

@@ -2138,6 +2138,7 @@ void TABLE_LIST::hide_view_error(THD *thd)
   /* Hide "Unknown column" or "Unknown function" error */
   if (thd->net.last_errno == ER_BAD_FIELD_ERROR ||
       thd->net.last_errno == ER_SP_DOES_NOT_EXIST ||
+      thd->net.last_errno == ER_FUNC_INEXISTENT_NAME_COLLISION ||
       thd->net.last_errno == ER_PROCACCESS_DENIED_ERROR ||
       thd->net.last_errno == ER_COLUMNACCESS_DENIED_ERROR ||
       thd->net.last_errno == ER_TABLEACCESS_DENIED_ERROR ||