Bug#20198490 : LOWER_CASE_TABLE_NAMES=0 ON WINDOWS LEADS TO

               PROBLEMS

Description:- Server variable "--lower_case_tables_names"
when set to "0" on windows platform which does not support
case sensitive file operations leads to problems. A warning
message is printed in the error log while starting the
server with "--lower_case_tables_names=0". Also according to
the documentation, seting "lower_case_tables_names" to "0"
on a case-insensitive filesystem might lead to index
corruption.

Analysis:- The problem reported in the bug is:-
Creating an INNODB table 'a' and executing a query, "INSERT
INTO a SELECT a FROM A;" on a server started with
"--lower_case_tables_names=0" and running on a
case-insensitive filesystem leads innodb to flat spin.
Optimizer thinks that "a" and "A" are two different tables
as the variable "lower_case_table_names" is set to "0". As a
result, optimizer comes up with a plan which does not need a
temporary table. If the same table is used in select and
insert, a temporary table is needed. This incorrect
optimizer plan leads to infinite insertions.

Fix:- If the server is started with
"--lower_case_tables_names" set to 0 on a case-insensitive
filesystem, an error, "The server option
'lower_case_table_names'is configured to use case sensitive
table names but the data directory is on a case-insensitive
file system which is an unsupported combination. Please
consider either using a case sensitive file system for your
data directory or switching to a case-insensitive table name
mode.", is printed in the server error log and the server
exits.

mysql-test/r/lowercase_fs_on.result

+#
+# Bug#20198490 : LOWER_CASE_TABLE_NAMES=0 ON WINDOWS LEADS TO PROBLEMS
+#

mysql-test/r/lowercase_table3.result

-call mtr.add_suppression("Cannot find or open table test/BUG29839 from");
-DROP TABLE IF EXISTS t1,T1;
-CREATE TABLE t1 (a INT);
-SELECT * FROM T1;
-a
-FLUSH TABLES;
-DROP TABLE t1;
-CREATE TABLE bug29839 (a INT) ENGINE=INNODB;
-SELECT * FROM BUG29839;
-ERROR 42S02: Table 'test.BUG29839' doesn't exist
-DROP TABLE bug29839;

mysql-test/suite/innodb/t/innodb_bug60229-master.opt

---lower_case_table_names=0

mysql-test/suite/innodb/t/innodb_bug60229.test

@@ -2,6 +2,10 @@
 # Bug #13083023 - 60229: BROKEN COMPATIBILITY: ERROR WHILE CREATE TABLE
 # WITH FOREIGN KEY CONSTRAINT.
 
+#Server variable option 'lower_case_table_names' sets '0' as default value
+#in case sensitive filesystem. Using 'lower_case_table_names=0' in case of
+#insensitive filsystem is not allowed.
+-- source include/have_case_sensitive_file_system.inc
 -- source include/have_innodb.inc
 
 CREATE TABLE PERSON (

mysql-test/suite/jp/t/jp_enum_sjis-master.opt

---lower_case_table_names=0

mysql-test/suite/jp/t/jp_enum_sjis.test

+#Server variable option 'lower_case_table_names' sets '0' as default value
+#in case sensitive filesystem. Using 'lower_case_table_names=0' in case of
+#insensitive filsystem is not allowed.
+-- source include/have_case_sensitive_file_system.inc
 --source include/have_sjis.inc
 --source include/have_innodb.inc
 --character_set sjis

mysql-test/suite/jp/t/jp_enum_ucs2-master.opt

---lower_case_table_names=0

mysql-test/suite/jp/t/jp_enum_ucs2.test

+#Server variable option 'lower_case_table_names' sets '0' as default value
+#in case sensitive filesystem. Using 'lower_case_table_names=0' in case of
+#insensitive filsystem is not allowed.
+-- source include/have_case_sensitive_file_system.inc
 --source include/have_ucs2.inc
 --source include/have_innodb.inc
 

mysql-test/suite/jp/t/jp_enum_ujis-master.opt

---lower_case_table_names=0

mysql-test/suite/jp/t/jp_enum_ujis.test

+#Server variable option 'lower_case_table_names' sets '0' as default value
+#in case sensitive filesystem. Using 'lower_case_table_names=0' in case of
+#insensitive filsystem is not allowed.
+-- source include/have_case_sensitive_file_system.inc
 --source include/have_ujis.inc
 --source include/have_innodb.inc
 

mysql-test/suite/jp/t/jp_enum_utf8-master.opt

---lower_case_table_names=0

mysql-test/suite/jp/t/jp_enum_utf8.test

+#Server variable option 'lower_case_table_names' sets '0' as default value
+#in case sensitive filesystem. Using 'lower_case_table_names=0' in case of
+#insensitive filsystem is not allowed.
+-- source include/have_case_sensitive_file_system.inc
 --source include/have_utf8.inc
 --source include/have_innodb.inc
 --disable_warnings

mysql-test/t/lowercase_fs_on.test

+#
+# Specific tests for case-insensitive file systems
+# i.e. lower_case_filesystem=ON
+#
+-- source include/have_case_insensitive_file_system.inc
+# Embedded server does not support restarting.
+--source include/not_embedded.inc
+
+--echo #
+--echo # Bug#20198490 : LOWER_CASE_TABLE_NAMES=0 ON WINDOWS LEADS TO PROBLEMS
+--echo #
+
+let SEARCH_FILE= $MYSQLTEST_VARDIR/log/my_restart.err;
+
+--error 0,1
+--remove_file $SEARCH_FILE
+
+#Shutdown the server
+--exec echo "wait" > $MYSQLTEST_VARDIR/tmp/mysqld.1.expect
+--shutdown_server
+--source include/wait_until_disconnected.inc
+
+#Start the server with --lower_case_table_names=0 in Windows.
+--enable_reconnect
+--error 1
+--exec $MYSQLD_CMD --lower_case_table_names=0 > $SEARCH_FILE  2>&1
+
+#Search for the error messege in the server error log.
+let SEARCH_PATTERN= \[ERROR\] The server option \'lower_case_table_names\' is configured to use case sensitive table names but the data directory is on a case-insensitive file system which is an unsupported combination\. Please consider either using a case sensitive file system for your data directory or switching to a case-insensitive table name mode\.;
+--source include/search_pattern_in_file.inc
+
+#Restart the server
+--exec echo "restart" > $MYSQLTEST_VARDIR/tmp/mysqld.1.expect
+--source include/wait_until_connected_again.inc
+
+#Cleanup
+--error 0,1
+--remove_file $SEARCH_FILE

mysql-test/t/lowercase_table3-master.opt

---lower_case_table_names=0

mysql-test/t/lowercase_table3.test

-#
-# Test of force of lower-case-table-names=0
-# (User has case insensitive file system and wants to preserve case of
-# table names)
-#
-
---source include/have_innodb.inc
---source include/have_lowercase0.inc
---source include/have_case_insensitive_file_system.inc
---source include/not_windows.inc
-
-call mtr.add_suppression("Cannot find or open table test/BUG29839 from");
-
---disable_warnings
-DROP TABLE IF EXISTS t1,T1;
---enable_warnings
-
-#
-# This is actually an error, but ok as the user has forced this
-# by using --lower-case-table-names=0
-CREATE TABLE t1 (a INT);
-SELECT * FROM T1;
-FLUSH TABLES;
-DROP TABLE t1;
-
-#
-# InnoDB should in this case be case sensitive
-# Note that this is not true on windows as no this OS, InnoDB is always
-# storing things in lower case.
-#
-
-CREATE TABLE bug29839 (a INT) ENGINE=INNODB;
---error ER_NO_SUCH_TABLE
-SELECT * FROM BUG29839;
-DROP TABLE bug29839;
-
-# End of 4.1 tests

sql/mysqld.cc

@@ -3551,13 +3551,14 @@ static int init_common_variables()
   {
     if (lower_case_table_names_used)
     {
-      if (global_system_variables.log_warnings)
-	sql_print_warning("\
-You have forced lower_case_table_names to 0 through a command-line \
-option, even though your file system '%s' is case insensitive.  This means \
-that you can corrupt a MyISAM table by accessing it with different cases. \
-You should consider changing lower_case_table_names to 1 or 2",
-			mysql_real_data_home);
+      sql_print_error("The server option 'lower_case_table_names' is "
+                      "configured to use case sensitive table names but the "
+                      "data directory is on a case-insensitive file system "
+                      "which is an unsupported combination. Please consider "
+                      "either using a case sensitive file system for your data "
+                      "directory or switching to a case-insensitive table name "
+                      "mode.");
+      return 1;
     }
     else
     {