Bug#19671 mysql_list_fields returns incorrect table name for VIEWs

After view onening real view db name and table name are placed
into table_list->view_db & table_list->view_name.
Item_field class does not handle these names properly during 
intialization of Send_field.
The fix is to use new class 'Item_ident_for_show' 
which sets correct view db name and table name for Send_field.

sql/item.cc

@@ -1457,7 +1457,18 @@ bool agg_item_charsets(DTCollation &coll, const char *fname,
 }
 
 
-
+void Item_ident_for_show::make_field(Send_field *tmp_field)
+{
+  tmp_field->table_name= tmp_field->org_table_name= table_name;
+  tmp_field->db_name= db_name;
+  tmp_field->col_name= tmp_field->org_col_name= field->field_name;
+  tmp_field->charsetnr= field->charset()->number;
+  tmp_field->length=field->field_length;
+  tmp_field->type=field->type();
+  tmp_field->flags= field->table->maybe_null ? 
+    (field->flags & ~NOT_NULL_FLAG) : field->flags;
+  tmp_field->decimals= 0;
+}
 
 /**********************************************/
 

sql/item.h

@@ -1142,6 +1142,28 @@ public:
                             bool any_privileges);
 };
 
+
+class Item_ident_for_show :public Item
+{
+public:
+  Field *field;
+  const char *db_name;
+  const char *table_name;
+
+  Item_ident_for_show(Field *par_field, const char *db_arg,
+                      const char *table_name_arg)
+    :field(par_field), db_name(db_arg), table_name(table_name_arg)
+  {}
+
+  enum Type type() const { return FIELD_ITEM; }
+  double val_real() { return field->val_real(); }
+  longlong val_int() { return field->val_int(); }
+  String *val_str(String *str) { return field->val_str(str); }
+  my_decimal *val_decimal(my_decimal *dec) { return field->val_decimal(dec); }
+  void make_field(Send_field *tmp_field);
+};
+
+
 class Item_equal;
 class COND_EQUAL;
 

sql/sql_show.cc

@@ -582,8 +582,15 @@ mysqld_list_fields(THD *thd, TABLE_LIST *table_list, const char *wild)
   {
     if (!wild || !wild[0] || 
         !wild_case_compare(system_charset_info, field->field_name,wild))
+    {
+      if (table_list->view)
+        field_list.push_back(new Item_ident_for_show(field,
+                                                     table_list->view_db.str,
+                                                     table_list->view_name.str));
+      else
         field_list.push_back(new Item_field(field));
     }
+  }
   restore_record(table, s->default_values);              // Get empty record
   if (thd->protocol->send_fields(&field_list, Protocol::SEND_DEFAULTS |
                                               Protocol::SEND_EOF))

tests/mysql_client_test.c

@@ -8311,6 +8311,39 @@ static void test_list_fields()
 }
 
 
+static void test_bug19671()
+{
+  MYSQL_RES *result;
+  int rc;
+  myheader("test_bug19671");
+
+  rc= mysql_query(mysql, "drop table if exists t1");
+  myquery(rc);
+
+  rc= mysql_query(mysql, "drop view if exists v1");
+  myquery(rc);
+
+  rc= mysql_query(mysql, "create table t1(f1 int)");
+  myquery(rc);
+
+  rc= mysql_query(mysql, "create view v1 as select va.* from t1 va");
+  myquery(rc);
+
+  result= mysql_list_fields(mysql, "v1", NULL);
+  mytest(result);
+
+  rc= my_process_result_set(result);
+  DIE_UNLESS(rc == 0);
+
+  verify_prepare_field(result, 0, "f1", "f1", MYSQL_TYPE_LONG,
+                       "v1", "v1", current_db, 11, "0");
+
+  mysql_free_result(result);
+  myquery(mysql_query(mysql, "drop view v1"));
+  myquery(mysql_query(mysql, "drop table t1"));
+}
+
+
 /* Test a memory ovverun bug */
 
 static void test_mem_overun()
@@ -15195,6 +15228,7 @@ static struct my_tests_st my_tests[]= {
   { "test_bug15613", test_bug15613 },
   { "test_bug14169", test_bug14169 },
   { "test_bug17667", test_bug17667 },
+  { "test_bug19671", test_bug19671},
   { 0, 0 }
 };