Commit edcd94d5816 for php.net

commit edcd94d5816ac072f34cd3a93f59905575bbfe39
Author: Ondřej Surý <ondrej@sury.org>
Date:   Wed Jul 8 11:27:30 2026 +0200

    ext/intl: don't include C++ ICU headers from C translation units (#22636)

    php_intl.c is compiled as C but transitively includes formatter_data.h and
    listformatter_class.h, which (since 8.6) include <unicode/numfmt.h> and
    <unicode/listformatter.h> unconditionally. On ICU >= 64 those C++ headers are
    a no-op in a C compile, but ICU 63 (Debian Buster) has an unguarded
    "#include <cstddef>" at the top of unistr.h, so the C compile fails with
    "fatal error: cstddef: No such file or directory".

    The C path only uses the "typedef void" shim (NumberFormat*/ListFormatter*
    are just void*), so it needs no ICU header at all. Move the C++ include inside
    the existing #ifdef __cplusplus guard. No-op on newer ICU.

diff --git a/ext/intl/formatter/formatter_data.h b/ext/intl/formatter/formatter_data.h
index 1208970471b..46a82cb9bd0 100644
--- a/ext/intl/formatter/formatter_data.h
+++ b/ext/intl/formatter/formatter_data.h
@@ -23,9 +23,8 @@ extern "C" {
 }
 #endif

-#include <unicode/numfmt.h>
-
 #ifdef __cplusplus
+#include <unicode/numfmt.h>
 using icu::NumberFormat;
 #else
 typedef void NumberFormat;
diff --git a/ext/intl/listformatter/listformatter_class.h b/ext/intl/listformatter/listformatter_class.h
index 7e7fd29207f..bdf21b6886e 100644
--- a/ext/intl/listformatter/listformatter_class.h
+++ b/ext/intl/listformatter/listformatter_class.h
@@ -21,9 +21,8 @@
 #include "intl_error.h"
 #include "intl_data.h"

-#include <unicode/listformatter.h>
-
 #ifdef __cplusplus
+#include <unicode/listformatter.h>
 using icu::ListFormatter;
 #else
 typedef void ListFormatter;