From 46ea7c3e3289fd6704f5fb4cfbb1421523ca1c7a Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 9 Sep 2025 09:10:44 +0900
Subject: [PATCH] musl: make strtoll() accept strings start with dot

glibc accepts strings start with '.' and returns 0, but musl refuses
them. Let's accept them, as our code assumes the function accept such
strings.
---
 src/include/musl/stdlib.h |  7 +++++++
 src/libc/musl/meson.build |  1 +
 src/libc/musl/stdlib.c    | 19 +++++++++++++++++++
 3 files changed, 27 insertions(+)
 create mode 100644 src/include/musl/stdlib.h
 create mode 100644 src/libc/musl/stdlib.c

diff --git a/src/include/musl/stdlib.h b/src/include/musl/stdlib.h
new file mode 100644
index 00000000000..ecfd6ccb430
--- /dev/null
+++ b/src/include/musl/stdlib.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include_next <stdlib.h>
+
+long long strtoll_fallback(const char *nptr, char **endptr, int base);
+#define strtoll strtoll_fallback
diff --git a/src/libc/musl/meson.build b/src/libc/musl/meson.build
index 78f93c35421..54866a8b612 100644
--- a/src/libc/musl/meson.build
+++ b/src/libc/musl/meson.build
@@ -6,5 +6,6 @@ endif
 
 libc_wrapper_sources += files(
         'stdio.c',
+        'stdlib.c',
         'string.c',
 )
diff --git a/src/libc/musl/stdlib.c b/src/libc/musl/stdlib.c
new file mode 100644
index 00000000000..1106fec9d0b
--- /dev/null
+++ b/src/libc/musl/stdlib.c
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <stdlib.h>
+
+/* The header stdlib.h overrides strtoll with strtoll_fallback, hence we need to undef it here. */
+#undef strtoll
+
+long long strtoll_fallback(const char *nptr, char **endptr, int base) {
+        /* glibc returns 0 if the first character is '.' without error, but musl returns as an error.
+         * As our code assumes the glibc behavior, let's accept strings start with '.'. */
+        if (nptr && *nptr == '.') {
+                if (endptr)
+                        *endptr = (char*) nptr;
+                return 0;
+        }
+
+        /* Otherwise, use the native strtoll(). */
+        return strtoll(nptr, endptr, base);
+}
-- 
2.47.3