Fix for:

bug #26215: mysql command line client should not strip comments
              from SQL statements
and
  bug #11230: Keeping comments when storing stored procedures

With the introduction of multiline comments support in the command line
client (mysql) in MySQL 4.1, it became impossible to preserve
client-side comments within single SQL statements or stored routines.
This feature was useful for monitoring tools and maintenance.

The patch adds a new option to the command line client
('--enable-comments', '-c') which allows to preserve SQL comments and
send them to the server for single SQL statements, and to keep comments
in the code for stored procedures / functions / triggers.

The patch is a modification of the contributed patch from bug #11230
with the following changes:
- code style changes to conform to the coding guidelines
- changed is_prefix() to my_strnncoll() to detect the DELIMITER
command, since the first one is case-sensitive and not charset-aware
- renamed t/comments-51.* to t/mysql_comments.*
- removed tests for comments in triggers since 5.0 does not have SHOW
CREATE TRIGGER (those tests will be added back in 5.1).

The test cases are only for bug #11230. No automated test case for bug
#26215 is possible due to the test suite deficiencies (though the cases
from the bug report were tested manually).

mysql-test/t/mysql_comments.test

@@ -0,0 +1,37 @@
+# This test should work in embedded server after we fix mysqltest
+-- source include/not_embedded.inc
+###################### mysql_comments.test #############################
+#                                                                      #
+# Testing of comments handling by the command line client (mysql)      #
+#                                                                      #
+# Creation:                                                            #
+# 2007-10-29 akopytov Implemented this test as a part of fixes for     #
+#                     bug #26215 and bug #11230                        #
+#                                                                      #
+########################################################################
+
+#
+# Bug #11230: Keeping comments when storing stored procedures
+#
+
+# See the content of mysql_comments.sql
+# Set the test database to a known state before running the tests.
+--disable_warnings
+drop table if exists t1;
+drop function if exists foofct;
+drop procedure if exists empty;
+drop procedure if exists foosp;
+drop procedure if exists nicesp;
+drop trigger if exists t1_empty;
+drop trigger if exists t1_bi;
+--enable_warnings
+
+# Test without comments
+--echo "Pass 1 : --disable-comments"
+--exec $MYSQL --disable-comments test 2>&1 < "./t/mysql_comments.sql"
+
+# Test with comments
+--echo "Pass 2 : --enable-comments"
+--exec $MYSQL --enable-comments test 2>&1 < "./t/mysql_comments.sql"
+
+--echo End of 5.0 tests