File 5413-init-Avoid-outputting-non-ASCII-characters... of Package erlang

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File 5413-init-Avoid-outputting-non-ASCII-characters-from-init.patch of Package erlang

From c2d5b70a37ce3596a86acc8c20cbbb813e33742c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Wed, 22 Feb 2023 06:36:30 +0100
Subject: [PATCH] init: Avoid outputting non-ASCII characters from -init_debug
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ba18068dc28693 (#6685) added printing of timing for the `-init_debug`
option:

{start,heart}
    {'done_in_µs',10}

With that change, the test case `peer_SUITE:init_debug/1` started to
fail sporadically. That test case tries to start a peer node with
option `-init_debug` using the connection type `standard_io`:

{ok, Peer, _Node} = peer:start_link(#{name => peer:random_name(?FUNCTION_NAME),
        shutdown => 1000,
        connection => standard_io, args => ["-init_debug"]}),

The test case would fail when the two bytes that comprise the `µ`
character were split up into two separate IO requests.

We could update the `peer` module so that it would do buffering and
re-combine split UTF-8 sequences. That would fix the failing test
case. However, introducing re-combining is not sufficient to make it
safe to print arbitrary non-ASCII characters, because of an
undocumented restriction mentioned in a comment for the `standard_io`
connection type:

%% Characters in range of 192-255 are reserved for control sequences,
    %%  see encode_port_data for details. If peer node attempts to print
    %%  characters in this range, an controlling process on the origin
    %%  node may terminate with an error (because CRC check will fail).

(The actual restriction is actually slightly less severe than the
comment implies, which is why `µ` would work after re-combining but
others characters such as `ö` would not. Note that the other connection
modes don't have this restriction, but they are not able to catch the
output from `-init_debug`.)

Since printing of arbitrary non-ASCII characters cannot be made safe
for the `standard_io` connection mode, change the printout of timing
information to only use ASCII characters:

{start,heart}
    {done_in_microseconds,10}
---
 erts/preloaded/ebin/init.beam | Bin 64272 -> 64256 bytes
 erts/preloaded/src/init.erl   |   2 +-
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/erts/preloaded/src/init.erl b/erts/preloaded/src/init.erl
index 45ca42778d..7933cfaa34 100644
--- a/erts/preloaded/src/init.erl
+++ b/erts/preloaded/src/init.erl
@@ -103,7 +103,7 @@ debug(_, T, Fun) ->
     Val = Fun(),
     T2 = erlang:monotonic_time(),
     Time = erlang:convert_time_unit(T2 - T1, native, microsecond),
-    erlang:display({'done_in_μs', Time}),
+    erlang:display({done_in_microseconds, Time}),
     Val.
 
 -spec get_arguments() -> Flags when
-- 
2.35.3

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File 5413-init-Avoid-outputting-non-ASCII-characters-from-init.patch of Package erlang

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