Bugs#17647: Trouble with "create database"

Problem:
if a user was granted privileges on database "d1",
it also was able to act on "D1" (i.e. in upper case),
even on Unix with case sensitive file system.

Fix:
Initialize grant hash to use binary comparison
if lower_case_file_system is not set (on most unixes),
and case insensitive comparison otherwise (Windows, MacOSX).

mysql-test/include/have_case_sensitive_file_system.inc

+--require r/case_sensitive_file_system.require
+--disable_query_log
+show variables like "lower_case_file_system";
+--enable_query_log

mysql-test/r/case_sensitive_file_system.require

+Variable_name	Value
+lower_case_file_system	OFF

mysql-test/r/lowercase_fs_off.result

+create database d1;
+grant all on d1.* to 'sample'@'localhost' identified by 'password';
+flush privileges;
+select database();
+database()
+d1
+create database d2;
+ERROR 42000: Access denied for user 'sample'@'localhost' to database 'd2'
+create database D1;
+ERROR 42000: Access denied for user 'sample'@'localhost' to database 'D1'
+drop database if exists d1;

mysql-test/t/lowercase_fs_off.test

+#
+# Specific tests for case sensitive file systems
+# i.e. lower_case_filesystem=OFF
+#
+-- source include/have_case_sensitive_file_system.inc
+
+connect (master,localhost,root,,);
+connection master;
+create database d1;
+grant all on d1.* to 'sample'@'localhost' identified by 'password';
+flush privileges;
+
+connect (sample,localhost,sample,password,d1);
+connection sample;
+select database();
+--error 1044
+create database d2;
+--error 1044
+create database D1;
+disconnect sample;
+
+connection master;
+drop database if exists d1;
+disconnect master;
+connection default;
+
+# End of 4.1 tests

sql/sql_acl.cc

@@ -146,7 +146,9 @@ my_bool acl_init(bool dont_read_acl_tables)
 
   acl_cache= new hash_filo(ACL_CACHE_SIZE, 0, 0,
                            (hash_get_key) acl_entry_get_key,
-                           (hash_free_key) free, system_charset_info);
+                           (hash_free_key) free,
+                           lower_case_file_system ?
+                           system_charset_info : &my_charset_bin);
   if (dont_read_acl_tables)
   {
     DBUG_RETURN(0); /* purecov: tested */