Re: [PATCH v0 1/3] utf8.c: Prepare workaround for iconv under macOS 14/15

From: Torsten Bögershausen <redacted>

MacOS14 (Sonoma) has started to ship an iconv library with bugs.
The same bugs exists even in MacOS 15 (Sequoia)

A bug report running the Git test suite says:

three tests of t3900 fail on macOS 26.1 for me:

  not ok 17 - ISO-2022-JP should be shown in UTF-8 now
  not ok 25 - ISO-2022-JP should be shown in UTF-8 now
  not ok 38 - commit --fixup into ISO-2022-JP from UTF-8

Here's the verbose output of the first one:

----- snip! -----
expecting success of 3900.17 'ISO-2022-JP should be shown in UTF-8 now':
                compare_with ISO-2022-JP "$TEST_DIRECTORY"/t3900/2-UTF-8.txt

--- /Users/x/src/git/t/t3900/2-UTF-8.txt 2024-10-01 19:43:24.605230684 +0000
+++ current     2025-12-08 21:52:45.786161909 +0000

@@ -1,4 +1,4 @@
 はれひほふ

 しているのが、いるので。
-濱浜ほれぷりぽれまびぐりろへ。
+濱浜ほれぷりぽれまび$0$j$m$X!#

not ok 17 - ISO-2022-JP should be shown in UTF-8 now
1..17
----- snap! -----

compare_with runs git show to display a commit message, which in this
case here was encoded using ISO-2022-JP and is supposed to be reencoded
to UTF-8, but git show only does that half-way -- the "$0$j$m$X!#" part
is from the original ISO-2022-JP representation.