small cleanup

* my_aes.h doesn't compile without my_global.h
* typo in a comment
* redundant condition
* if encryption plugin fails, there's no encryption_key_manager
  at plugin deinit time
* encryption plugin tests must run when plugin.so is present,
  not when a plugin is active (otherwise the test will be skipped
  when plugin fails to initialize).

include/my_aes.h

@@ -22,6 +22,8 @@
 #ifndef MY_AES_INCLUDED
 #define MY_AES_INCLUDED
 
+#include <my_global.h>
+
 typedef int Crypt_result;
 
 #define AES_OK 0

include/mysql/service_thd_alloc.h

@@ -16,7 +16,7 @@
 
 /**
   @file
-  This service provdes functions to allocate memory in a connection local
+  This service provides functions to allocate memory in a connection local
   memory pool. The memory allocated there will be automatically freed at the
   end of the statement, don't use it for allocations that should live longer
   than that. For short living allocations this is more efficient than

mysql-test/include/have_example_key_management_plugin.inc

 -- source encryption_algorithms.inc
 
-if (`select count(*) = 0 from information_schema.plugins
-     where plugin_name = 'example_key_management' and plugin_status='active'`)
+if (!$EXAMPLE_KEY_MANAGEMENT_SO)
 {
   --skip Needs example_key_management
 }

mysql-test/include/have_file_key_management_plugin.inc

 -- source encryption_algorithms.inc
 
-if (`select count(*) = 0 from information_schema.plugins
-     where plugin_name = 'file_key_management' and plugin_status='active'`)
+if (!$FILE_KEY_MANAGEMENT_SO)
 {
   --skip Needs file_key_management
 }

mysys/my_fopen.c

@@ -87,8 +87,7 @@ FILE *my_fopen(const char *filename, int flags, myf MyFlags)
     my_errno=errno;
   DBUG_PRINT("error",("Got error %d on open",my_errno));
   if (MyFlags & (MY_FFNF | MY_FAE | MY_WME))
-    my_error((flags & O_RDONLY) || (flags == O_RDONLY ) ? EE_FILENOTFOUND :
-	     EE_CANTCREATEFILE,
+    my_error((flags & O_RDONLY) ? EE_FILENOTFOUND : EE_CANTCREATEFILE,
 	     MYF(ME_BELL+ME_WAITTANG), filename, my_errno);
   DBUG_RETURN((FILE*) 0);
 } /* my_fopen */

sql/encryption_keys.cc

@@ -59,14 +59,13 @@ int initialize_encryption_key_management_plugin(st_plugin_int *plugin)
 
 int finalize_encryption_key_management_plugin(st_plugin_int *plugin)
 {
-  DBUG_ASSERT(encryption_key_manager);
-
   if (plugin->plugin->deinit && plugin->plugin->deinit(NULL))
   {
     DBUG_PRINT("warning", ("Plugin '%s' deinit function returned error.",
                            plugin->name.str));
   }
-  plugin_unlock(NULL, encryption_key_manager);
+  if (encryption_key_manager)
+    plugin_unlock(NULL, encryption_key_manager);
   encryption_key_manager= 0;
   return 0;
 }