From 5c32f2221c6b6d0e1e358aca113e4a2f40b50829 Mon Sep 17 00:00:00 2001
From: Hans Bolinder <hasse@erlang.org>
Date: Mon, 2 Jul 2012 13:03:47 +0200
Subject: [PATCH] Correct the type of the disk log header

Thanks to Niclas Eklund.
---
 lib/kernel/src/disk_log.erl        |  7 +++++--
 lib/kernel/src/disk_log.hrl        |  4 ++--
 lib/kernel/test/disk_log_SUITE.erl | 24 ++++++++++++++++++++----
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/lib/kernel/src/disk_log.erl b/lib/kernel/src/disk_log.erl
index f5f972c11213..5b1efcd395e7 100644
--- a/lib/kernel/src/disk_log.erl
+++ b/lib/kernel/src/disk_log.erl
@@ -282,7 +282,8 @@ change_notify(Log, Pid, NewNotify) ->
 
 -spec change_header(Log, Header) -> 'ok' | {'error', Reason} when
       Log :: log(),
-      Header :: {head, dlog_head_opt()} | {head_func, mfa()},
+      Header :: {head, dlog_head_opt()}
+              | {head_func, MFA :: {atom(), atom(), list()}},
       Reason :: no_such_log | nonode | {read_only_mode, Log}
               | {blocked_log, Log} | {badarg, head}.
 change_header(Log, NewHead) ->
@@ -336,7 +337,9 @@ format_error(Error) ->
                         ok | {blocked, QueueLogRecords :: boolean()}}
                    | {node, Node :: node()}
                    | {distributed, Dist :: local | [node()]}
-                   | {head, Head :: none | {head, term()} | mfa()}
+                   | {head, Head :: none
+                                  | {head, term()}
+                                  | (MFA :: {atom(), atom(), list()})}
                    | {no_written_items, NoWrittenItems ::non_neg_integer()}
                    | {full, Full :: boolean}
                    | {no_current_bytes, non_neg_integer()}
diff --git a/lib/kernel/src/disk_log.hrl b/lib/kernel/src/disk_log.hrl
index 259967650fd2..242a25a7a65f 100644
--- a/lib/kernel/src/disk_log.hrl
+++ b/lib/kernel/src/disk_log.hrl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1997-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2012. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -74,7 +74,7 @@
                           | {distributed, Nodes :: [node()]}
                           | {notify, boolean()}
                           | {head, Head :: dlog_head_opt()}
-                          | {head_func, mfa()}
+                          | {head_func, MFA :: {atom(), atom(), list()}}
                           | {mode, Mode :: dlog_mode()}.
 -type dlog_options()     :: [dlog_option()].
 -type dlog_repair()      :: 'truncate' | boolean().
diff --git a/lib/kernel/test/disk_log_SUITE.erl b/lib/kernel/test/disk_log_SUITE.erl
index ad987fe7a710..0c3f5c3514bb 100644
--- a/lib/kernel/test/disk_log_SUITE.erl
+++ b/lib/kernel/test/disk_log_SUITE.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1997-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2012. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -90,7 +90,7 @@
 
          evil/1,
 
-         otp_6278/1]).
+         otp_6278/1, otp_10131/1]).
 
 -export([head_fun/1, hf/0, lserv/1, 
 	 measure/0, init_m/1, xx/0, head_exit/0, slow_header/1]).
@@ -124,7 +124,7 @@
 	[halt_int, wrap_int, halt_ext, wrap_ext, read_mode, head,
 	 notif, new_idx_vsn, reopen, block, unblock, open, close,
 	 error, chunk, truncate, many_users, info, change_size,
-	 change_attribute, distribution, evil, otp_6278]).
+	 change_attribute, distribution, evil, otp_6278, otp_10131]).
 
 %% The following two lists should be mutually exclusive. To skip a case
 %% on VxWorks altogether, use the kernel.spec.vxworks file instead.
@@ -153,7 +153,7 @@ all() ->
      {group, open}, {group, close}, {group, error}, chunk,
      truncate, many_users, {group, info},
      {group, change_size}, change_attribute,
-     {group, distribution}, evil, otp_6278].
+     {group, distribution}, evil, otp_6278, otp_10131].
 
 groups() -> 
     [{halt_int, [], [halt_int_inf, {group, halt_int_sz}]},
@@ -4915,6 +4915,22 @@ otp_6278(Conf) when is_list(Conf) ->
     end,
     ?line error_logger:delete_report_handler(?MODULE).
 
+otp_10131(suite) -> [];
+otp_10131(doc) -> ["OTP-10131. head_func type."];
+otp_10131(Conf) when is_list(Conf) ->
+    Dir = ?privdir(Conf),
+    Log = otp_10131,
+    File = filename:join(Dir, lists:concat([Log, ".LOG"])),
+    HeadFunc = {?MODULE, head_fun, [{ok,"head"}]},
+    {ok, Log} = disk_log:open([{name,Log},{file,File},
+                               {head_func, HeadFunc}]),
+    HeadFunc = info(Log, head, undef),
+    HeadFunc2 = {?MODULE, head_fun, [{ok,"head2"}]},
+    ok = disk_log:change_header(Log, {head_func, HeadFunc2}),
+    HeadFunc2 = info(Log, head, undef),
+    ok = disk_log:close(Log),
+    ok.
+
 mark(FileName, What) ->
     {ok,Fd} = file:open(FileName, [raw, binary, read, write]),
     {ok,_} = file:position(Fd, 4),