Add a "fork" of musl as //fusl.

fusl/src/passwd/getpw_r.c

Index: fusl/src/passwd/getpw_r.c
diff --git a/fusl/src/passwd/getpw_r.c b/fusl/src/passwd/getpw_r.c
new file mode 100644
index 0000000000000000000000000000000000000000..e8cc811e4d898f91c26d05b16b4456fda9d6601b
--- /dev/null
+++ b/fusl/src/passwd/getpw_r.c
@@ -0,0 +1,41 @@
+#include "pwf.h"
+#include <pthread.h>
+
+#define FIX(x) (pw->pw_##x = pw->pw_##x-line+buf)
+
+static int getpw_r(const char *name, uid_t uid, struct passwd *pw, char *buf, size_t size, struct passwd **res)
+{
+	char *line = 0;
+	size_t len = 0;
+	int rv = 0;
+	int cs;
+
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+
+	rv = __getpw_a(name, uid, pw, &line, &len, res);
+	if (*res && size < len) {
+		*res = 0;
+		rv = ERANGE;
+	}
+	if (*res) {
+		memcpy(buf, line, len);
+		FIX(name);
+		FIX(passwd);
+		FIX(gecos);
+		FIX(dir);
+		FIX(shell);
+	}
+ 	free(line);
+	pthread_setcancelstate(cs, 0);
+	return rv;
+}
+
+int getpwnam_r(const char *name, struct passwd *pw, char *buf, size_t size, struct passwd **res)
+{
+	return getpw_r(name, 0, pw, buf, size, res);
+}
+
+int getpwuid_r(uid_t uid, struct passwd *pw, char *buf, size_t size, struct passwd **res)
+{
+	return getpw_r(0, uid, pw, buf, size, res);
+}