Bug#28779 (mysql_query() allows execution of statements with unbalanced

comments)

This change set is for 5.1 (manually merged)

Before this fix, the server would accept queries that contained comments,
even when the comments were not properly closed with a '*' '/' marker.

For example,
  select 1 /* + 2 <EOF>
would be accepted as
  select 1 /* + 2 */ <EOF>
and executed as
  select 1

With this fix, the server now rejects queries with unclosed comments
as syntax errors.
Both regular comments ('/' '*') and special comments ('/' '*' '!') must be
closed with '*' '/' to be parsed correctly.


mysql-test/r/comments.result:
  Unbalanced comments are a syntax error.
mysql-test/t/comments.test:
  Unbalanced comments are a syntax error.
sql/sql_lex.cc:
  Unbalanced comments are a syntax error.

1 files changed, 31 insertions, 0 deletions

diff --git a/mysql-test/t/comments.test b/mysql-test/t/comments.test
index 8ae6ba5779e..3a18a8bd483 100644
--- a/mysql-test/t/comments.test
+++ b/mysql-test/t/comments.test
@@ -34,3 +34,34 @@ select 1/*!999992*/;
 
 select 1 + /*!00000 2 */ + 3 /*!99999 noise*/ + 4;
 
+#
+# Bug#28779 (mysql_query() allows execution of statements with unbalanced
+# comments)
+#
+
+--disable_warnings
+drop table if exists table_28779;
+--enable_warnings
+
+create table table_28779 (a int);
+
+--error 1064
+prepare bar from "DELETE FROM table_28779 WHERE a = 7 OR 1=1/*' AND b = 'bar';";
+
+--error 1064
+prepare bar from "DELETE FROM table_28779 WHERE a = 7 OR 1=1/*' AND b = 'bar';*";
+
+--error 1064
+prepare bar from "DELETE FROM table_28779 WHERE a = 7 OR 1=1/*! AND 2=2;";
+
+--error 1064
+prepare bar from "DELETE FROM table_28779 WHERE a = 7 OR 1=1/*! AND 2=2;*";
+
+--error 1064
+prepare bar from "DELETE FROM table_28779 WHERE a = 7 OR 1=1/*!98765' AND b = 'bar';";
+
+--error 1064
+prepare bar from "DELETE FROM table_28779 WHERE a = 7 OR 1=1/*!98765' AND b = 'bar';*";
+
+drop table table_28779;
+