From 4d84803ac2cc300242d8846f2f1e93acaf4ab43d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?John=20H=C3=B6gberg?= <john@erlang.org>
Date: Wed, 19 Feb 2025 09:21:16 +0100
Subject: [PATCH] erts: Restore an optimization in
 unicode:characters_to_binary/1,3

---
 erts/emulator/beam/erl_unicode.c  |  2 +-
 lib/stdlib/test/unicode_SUITE.erl | 11 +++++++++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/erts/emulator/beam/erl_unicode.c b/erts/emulator/beam/erl_unicode.c
index 970ca89bd9c0..55ecca303c90 100644
--- a/erts/emulator/beam/erl_unicode.c
+++ b/erts/emulator/beam/erl_unicode.c
@@ -188,7 +188,7 @@ static Sint aligned_binary_size(Eterm binary)
     Uint size = bitstring_size(binary);
 
     if (TAIL_BITS(size) == 0 && size <= ERTS_SINT_MAX) {
-        return (Sint)size;
+        return (Sint)BYTE_SIZE(size);
     }
 
     return -1;
diff --git a/lib/stdlib/test/unicode_SUITE.erl b/lib/stdlib/test/unicode_SUITE.erl
index 1edc8a7d8d2a..ca5b33c5e72d 100644
--- a/lib/stdlib/test/unicode_SUITE.erl
+++ b/lib/stdlib/test/unicode_SUITE.erl
@@ -36,7 +36,8 @@
 	 ex_binaries_errors_utf32_big/1,
          normalize/1,
          huge_illegal_code_points/1,
-         error_info/1
+         error_info/1,
+         bin_is_7bit/1
         ]).
 
 suite() ->
@@ -51,7 +52,8 @@ all() ->
      normalize,
      {group,binaries_errors},
      huge_illegal_code_points,
-     error_info].
+     error_info,
+     bin_is_7bit].
 
 groups() -> 
     [{binaries_errors,[parallel],
@@ -1454,6 +1456,11 @@ error_info(_Config) ->
         ],
     error_info_lib:test_error_info(unicode, L).
 
+bin_is_7bit(_Config) ->
+    true = unicode:bin_is_7bit(<<"d"/utf8>>),
+    false = unicode:bin_is_7bit(<<"ö"/utf8>>),
+    ok.
+
 %%%
 %%% Utilities.
 %%%