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

comments)

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, 15 insertions, 0 deletions

diff --git a/mysql-test/r/comments.result b/mysql-test/r/comments.result
index a9106ce0538..1040c3fc8e9 100644
--- a/mysql-test/r/comments.result
+++ b/mysql-test/r/comments.result
@@ -26,3 +26,18 @@ select 1 # The rest of the row will be ignored
 1
 1
 /* line with only comment */;
+drop table if exists table_28779;
+create table table_28779 (a int);
+prepare bar from "DELETE FROM table_28779 WHERE a = 7 OR 1=1/*' AND b = 'bar';";
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '/*' AND b = 'bar'' at line 1
+prepare bar from "DELETE FROM table_28779 WHERE a = 7 OR 1=1/*' AND b = 'bar';*";
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '/*' AND b = 'bar';*' at line 1
+prepare bar from "DELETE FROM table_28779 WHERE a = 7 OR 1=1/*! AND 2=2;";
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
+prepare bar from "DELETE FROM table_28779 WHERE a = 7 OR 1=1/*! AND 2=2;*";
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ';*' at line 1
+prepare bar from "DELETE FROM table_28779 WHERE a = 7 OR 1=1/*!98765' AND b = 'bar';";
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '/*!98765' AND b = 'bar'' at line 1
+prepare bar from "DELETE FROM table_28779 WHERE a = 7 OR 1=1/*!98765' AND b = 'bar';*";
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '/*!98765' AND b = 'bar';*' at line 1
+drop table table_28779;