diff --git a/README.md b/README.md
index 113ffd7..aafbcff 100644
--- a/README.md
+++ b/README.md
@@ -374,6 +374,19 @@
 
     $ ./tests/run-on-host.sh glibc
 
+### Against musl
+
+Another way to verify test behavior is to run against musl on the host. glibc
+musl don't always match, so this can be a good way to find the more complicated
+corners of the spec. If they *do* match, bionic probably should too!
+
+    $ OUT_DIR=$(ANDROID_BUILD_TOP)/musl-out ./tests/run-on-host.sh musl
+
+Note: the alternate OUT_DIR is used to avoid causing excessive rebuilding when
+switching between glibc and musl. The first musl test run will be expensive
+because it will not reuse any already built artifacts, but subsequent runs will
+be cheaper than if you hadn't used it.
+
 ## Gathering test coverage
 
 To get test coverage for bionic, use `//bionic/build/coverage.sh`. Before
diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index 5f49c8c..e8dde7c 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -161,7 +161,7 @@
 int linkat(int, const char*, int, const char*, int)  all
 int mkdirat(int, const char*, mode_t)  all
 int mknodat(int, const char*, mode_t, dev_t)  all
-int readlinkat(int, const char*, char*, size_t)  all
+ssize_t readlinkat(int, const char*, char*, size_t)  all
 int renameat2(int, const char*, int, const char*, unsigned)  all
 int symlinkat(const char*, int, const char*)  all
 int unlinkat(int, const char*, int)   all
diff --git a/libc/include/bits/getentropy.h b/libc/include/bits/getentropy.h
new file mode 100644
index 0000000..a5a14f7
--- /dev/null
+++ b/libc/include/bits/getentropy.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#pragma once
+
+/**
+ * @file bits/getentropy.h
+ * @brief The getentropy() function.
+ */
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+__BEGIN_DECLS
+
+/**
+ * [getentropy(3)](http://man7.org/linux/man-pages/man3/getentropy.3.html) fills the given buffer
+ * with random bytes.
+ *
+ * Returns 0 on success, and returns -1 and sets `errno` on failure.
+ *
+ * Available since API level 28.
+ *
+ * See also arc4random_buf() which is available in all API levels.
+ */
+int getentropy(void* _Nonnull __buffer, size_t __buffer_size) __wur __INTRODUCED_IN(28);
+
+__END_DECLS
diff --git a/libc/include/sys/cachectl.h b/libc/include/sys/cachectl.h
index fd775ee..b5fabe3 100644
--- a/libc/include/sys/cachectl.h
+++ b/libc/include/sys/cachectl.h
@@ -37,6 +37,8 @@
 
 __BEGIN_DECLS
 
+#if defined(__riscv)
+
 /**
  * Flag for __riscv_flush_icache() to indicate that only the current
  * thread's instruction cache needs to be flushed (rather than the
@@ -46,9 +48,12 @@
 
 /**
  * __riscv_flush_icache(2) flushes the instruction cache for the given range of addresses.
+ * The address range is currently (Linux 6.4) ignored, so both pointers may be null.
  *
  * Returns 0 on success, and returns -1 and sets `errno` on failure.
  */
-int __riscv_flush_icache(void* __start, void* __end, unsigned long __flags);
+int __riscv_flush_icache(void* _Nullable __start, void* _Nullable __end, unsigned long __flags);
+
+#endif
 
 __END_DECLS
diff --git a/libc/include/sys/random.h b/libc/include/sys/random.h
index 0251176..2ff5349 100644
--- a/libc/include/sys/random.h
+++ b/libc/include/sys/random.h
@@ -38,19 +38,9 @@
 
 #include <linux/random.h>
 
-__BEGIN_DECLS
+#include <bits/getentropy.h>
 
-/**
- * [getentropy(3)](http://man7.org/linux/man-pages/man3/getentropy.3.html) fills the given buffer
- * with random bytes.
- *
- * Returns 0 on success, and returns -1 and sets `errno` on failure.
- *
- * Available since API level 28.
- *
- * See also arc4random_buf() which is available in all API levels.
- */
-int getentropy(void* _Nonnull __buffer, size_t __buffer_size) __wur __INTRODUCED_IN(28);
+__BEGIN_DECLS
 
 /**
  * [getrandom(2)](http://man7.org/linux/man-pages/man2/getrandom.2.html) fills the given buffer
diff --git a/libc/include/unistd.h b/libc/include/unistd.h
index 9385264..dcad630 100644
--- a/libc/include/unistd.h
+++ b/libc/include/unistd.h
@@ -34,6 +34,7 @@
 #include <sys/select.h>
 
 #include <bits/fcntl.h>
+#include <bits/getentropy.h>
 #include <bits/getopt.h>
 #include <bits/ioctl.h>
 #include <bits/lockf.h>
diff --git a/libc/private/thread_private.h b/libc/private/thread_private.h
index 1f9eeb6..1a13690 100644
--- a/libc/private/thread_private.h
+++ b/libc/private/thread_private.h
@@ -29,7 +29,6 @@
 
 #define _ARC4_LOCK() _thread_arc4_lock()
 #define _ARC4_UNLOCK() _thread_arc4_unlock()
-#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
 
 extern volatile sig_atomic_t _rs_forked;
 
diff --git a/libc/upstream-freebsd/lib/libc/locale/wcsftime.c b/libc/upstream-freebsd/lib/libc/locale/wcsftime.c
index aabb632..4fe6ad5 100644
--- a/libc/upstream-freebsd/lib/libc/locale/wcsftime.c
+++ b/libc/upstream-freebsd/lib/libc/locale/wcsftime.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2002 Tim J. Robbins
  * All rights reserved.
diff --git a/libc/upstream-freebsd/lib/libc/stdlib/getopt_long.c b/libc/upstream-freebsd/lib/libc/stdlib/getopt_long.c
index 6a3067c..1f3548b 100644
--- a/libc/upstream-freebsd/lib/libc/stdlib/getopt_long.c
+++ b/libc/upstream-freebsd/lib/libc/stdlib/getopt_long.c
@@ -55,7 +55,7 @@
 #endif /* LIBC_SCCS and not lint */
 #endif
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/stdlib/getopt_long.c 342757 2019-01-04 03:13:24Z kevans $");
+__FBSDID("$FreeBSD$");
 
 #include <err.h>
 #include <errno.h>
@@ -88,7 +88,7 @@
 #define	BADARG		((*options == ':') ? (int)':' : (int)'?')
 #define	INORDER 	(int)1
 
-#define	EMSG		""
+static char EMSG[] = "";
 
 #ifdef GNU_COMPATIBLE
 #define NO_PREFIX	(-1)
@@ -194,7 +194,7 @@
 {
 	char *current_argv, *has_equal;
 #ifdef GNU_COMPATIBLE
-	char *current_dash;
+	const char *current_dash;
 #endif
 	size_t current_argv_len;
 	int i, match, exact_match, second_partial_match;
diff --git a/libc/upstream-freebsd/lib/libc/stdlib/hcreate.c b/libc/upstream-freebsd/lib/libc/stdlib/hcreate.c
index b175d34..c9a0847 100644
--- a/libc/upstream-freebsd/lib/libc/stdlib/hcreate.c
+++ b/libc/upstream-freebsd/lib/libc/stdlib/hcreate.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2015 Nuxi, https://nuxi.nl/
  *
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/stdlib/hcreate.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <search.h>
 #include <stdbool.h>
diff --git a/libc/upstream-freebsd/lib/libc/stdlib/hcreate_r.c b/libc/upstream-freebsd/lib/libc/stdlib/hcreate_r.c
index 34db88e..83e322a 100644
--- a/libc/upstream-freebsd/lib/libc/stdlib/hcreate_r.c
+++ b/libc/upstream-freebsd/lib/libc/stdlib/hcreate_r.c
@@ -24,7 +24,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/stdlib/hcreate_r.c 292767 2015-12-27 07:50:11Z ed $");
+__FBSDID("$FreeBSD$");
 
 #include <search.h>
 #include <stdlib.h>
diff --git a/libc/upstream-freebsd/lib/libc/stdlib/hdestroy_r.c b/libc/upstream-freebsd/lib/libc/stdlib/hdestroy_r.c
index 76d8a42..890bd08 100644
--- a/libc/upstream-freebsd/lib/libc/stdlib/hdestroy_r.c
+++ b/libc/upstream-freebsd/lib/libc/stdlib/hdestroy_r.c
@@ -24,7 +24,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/stdlib/hdestroy_r.c 292767 2015-12-27 07:50:11Z ed $");
+__FBSDID("$FreeBSD$");
 
 #include <search.h>
 #include <stdlib.h>
diff --git a/libc/upstream-freebsd/lib/libc/stdlib/hsearch.h b/libc/upstream-freebsd/lib/libc/stdlib/hsearch.h
index a0542b5..649933d 100644
--- a/libc/upstream-freebsd/lib/libc/stdlib/hsearch.h
+++ b/libc/upstream-freebsd/lib/libc/stdlib/hsearch.h
@@ -22,7 +22,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $FreeBSD: head/lib/libc/stdlib/hsearch.h 292767 2015-12-27 07:50:11Z ed $
+ * $FreeBSD$
  */
 
 #ifndef HSEARCH_H
diff --git a/libc/upstream-freebsd/lib/libc/stdlib/hsearch_r.c b/libc/upstream-freebsd/lib/libc/stdlib/hsearch_r.c
index 9a859d3..2fb5991 100644
--- a/libc/upstream-freebsd/lib/libc/stdlib/hsearch_r.c
+++ b/libc/upstream-freebsd/lib/libc/stdlib/hsearch_r.c
@@ -24,7 +24,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/stdlib/hsearch_r.c 292767 2015-12-27 07:50:11Z ed $");
+__FBSDID("$FreeBSD$");
 
 #include <errno.h>
 #include <limits.h>
diff --git a/libc/upstream-freebsd/lib/libc/stdlib/quick_exit.c b/libc/upstream-freebsd/lib/libc/stdlib/quick_exit.c
index 9e4e79d..d486b1a 100644
--- a/libc/upstream-freebsd/lib/libc/stdlib/quick_exit.c
+++ b/libc/upstream-freebsd/lib/libc/stdlib/quick_exit.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2011 David Chisnall
  * All rights reserved.
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $FreeBSD: head/lib/libc/stdlib/quick_exit.c 326193 2017-11-25 17:12:48Z pfg $
+ * $FreeBSD$
  */
 
 #include <sys/types.h>
diff --git a/libc/upstream-freebsd/lib/libc/string/wcpcpy.c b/libc/upstream-freebsd/lib/libc/string/wcpcpy.c
index e040dba..41b7c51 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcpcpy.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcpcpy.c
@@ -35,7 +35,7 @@
 static char sccsid[] = "@(#)strcpy.c	8.1 (Berkeley) 6/4/93";
 #endif /* LIBC_SCCS and not lint */
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/string/wcpcpy.c 326025 2017-11-20 19:49:47Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcpncpy.c b/libc/upstream-freebsd/lib/libc/string/wcpncpy.c
index 8bf6e87..ccc64cd 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcpncpy.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcpncpy.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2009 David Schultz <das@FreeBSD.org>
  * All rights reserved.
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/string/wcpncpy.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcscasecmp.c b/libc/upstream-freebsd/lib/libc/string/wcscasecmp.c
index 5bd468d..03a61f8 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcscasecmp.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcscasecmp.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2009 David Schultz <das@FreeBSD.org>
  * All rights reserved.
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/string/wcscasecmp.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 #include <wctype.h>
diff --git a/libc/upstream-freebsd/lib/libc/string/wcscat.c b/libc/upstream-freebsd/lib/libc/string/wcscat.c
index 792f61e..777a576 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcscat.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcscat.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c)1999 Citrus Project,
  * All rights reserved.
@@ -34,7 +34,7 @@
 __RCSID("$NetBSD: wcscat.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wcscat.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcschr.c b/libc/upstream-freebsd/lib/libc/string/wcschr.c
index ca740c0..a7f1de0 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcschr.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcschr.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2002 Tim J. Robbins
  * All rights reserved.
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/string/wcschr.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcscmp.c b/libc/upstream-freebsd/lib/libc/string/wcscmp.c
index db01892..7205238 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcscmp.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcscmp.c
@@ -39,7 +39,7 @@
 __RCSID("$NetBSD: wcscmp.c,v 1.3 2001/01/05 12:13:12 itojun Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
-__FBSDID("$FreeBSD: head/lib/libc/string/wcscmp.c 326025 2017-11-20 19:49:47Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcscpy.c b/libc/upstream-freebsd/lib/libc/string/wcscpy.c
index a639e74..b400fae 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcscpy.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcscpy.c
@@ -34,7 +34,7 @@
 __RCSID("$NetBSD: wcscpy.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wcscpy.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcscspn.c b/libc/upstream-freebsd/lib/libc/string/wcscspn.c
index 8a7682f..a0db715 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcscspn.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcscspn.c
@@ -34,7 +34,7 @@
 __RCSID("$NetBSD: wcscspn.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wcscspn.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcsdup.c b/libc/upstream-freebsd/lib/libc/string/wcsdup.c
index b97f766..327574b 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcsdup.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcsdup.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2005 Tim J. Robbins.
  * All rights reserved.
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/string/wcsdup.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <stdlib.h>
 #include <wchar.h>
diff --git a/libc/upstream-freebsd/lib/libc/string/wcslcat.c b/libc/upstream-freebsd/lib/libc/string/wcslcat.c
index 9706fa6..f954b73 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcslcat.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcslcat.c
@@ -35,7 +35,7 @@
 __RCSID("$NetBSD: wcslcat.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wcslcat.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <sys/types.h>
 #include <wchar.h>
diff --git a/libc/upstream-freebsd/lib/libc/string/wcslen.c b/libc/upstream-freebsd/lib/libc/string/wcslen.c
index c596825..cfd3aa2 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcslen.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcslen.c
@@ -34,7 +34,7 @@
 __RCSID("$NetBSD: wcslen.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wcslen.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcsncasecmp.c b/libc/upstream-freebsd/lib/libc/string/wcsncasecmp.c
index a963444..39f58be 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcsncasecmp.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcsncasecmp.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2009 David Schultz <das@FreeBSD.org>
  * All rights reserved.
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/string/wcsncasecmp.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 #include <wctype.h>
diff --git a/libc/upstream-freebsd/lib/libc/string/wcsncat.c b/libc/upstream-freebsd/lib/libc/string/wcsncat.c
index 0214af4..eb13fab 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcsncat.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcsncat.c
@@ -34,7 +34,7 @@
 __RCSID("$NetBSD: wcsncat.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wcsncat.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcsncmp.c b/libc/upstream-freebsd/lib/libc/string/wcsncmp.c
index 77b709c..55c88f6 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcsncmp.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcsncmp.c
@@ -36,7 +36,7 @@
 __RCSID("$NetBSD: wcsncmp.c,v 1.3 2001/01/05 12:13:13 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wcsncmp.c 326025 2017-11-20 19:49:47Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcsncpy.c b/libc/upstream-freebsd/lib/libc/string/wcsncpy.c
index 4075ecc..f86e40f 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcsncpy.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcsncpy.c
@@ -38,7 +38,7 @@
 #endif /* LIBC_SCCS and not lint */
 #endif
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/string/wcsncpy.c 326025 2017-11-20 19:49:47Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcsnlen.c b/libc/upstream-freebsd/lib/libc/string/wcsnlen.c
index 271d341..15fd520 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcsnlen.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcsnlen.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2009 David Schultz <das@FreeBSD.org>
  * All rights reserved.
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/string/wcsnlen.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcspbrk.c b/libc/upstream-freebsd/lib/libc/string/wcspbrk.c
index 63efb01..0e9ccf6 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcspbrk.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcspbrk.c
@@ -34,7 +34,7 @@
 __RCSID("$NetBSD: wcspbrk.c,v 1.1 2000/12/23 23:14:37 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wcspbrk.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcsrchr.c b/libc/upstream-freebsd/lib/libc/string/wcsrchr.c
index 97665ca..cc5e7f2 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcsrchr.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcsrchr.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2002 Tim J. Robbins
  * All rights reserved.
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/string/wcsrchr.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcsspn.c b/libc/upstream-freebsd/lib/libc/string/wcsspn.c
index b08a39e..2b08acb 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcsspn.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcsspn.c
@@ -34,7 +34,7 @@
 __RCSID("$NetBSD: wcsspn.c,v 1.1 2000/12/23 23:14:37 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wcsspn.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcsstr.c b/libc/upstream-freebsd/lib/libc/string/wcsstr.c
index 4309025..74921fe 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcsstr.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcsstr.c
@@ -38,7 +38,7 @@
 #endif /* LIBC_SCCS and not lint */
 #endif
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/string/wcsstr.c 326025 2017-11-20 19:49:47Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wcstok.c b/libc/upstream-freebsd/lib/libc/string/wcstok.c
index 8d62bf7..b4bdc86 100644
--- a/libc/upstream-freebsd/lib/libc/string/wcstok.c
+++ b/libc/upstream-freebsd/lib/libc/string/wcstok.c
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libc/string/wcstok.c 326025 2017-11-20 19:49:47Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wmemchr.c b/libc/upstream-freebsd/lib/libc/string/wmemchr.c
index 412a276..42ae286 100644
--- a/libc/upstream-freebsd/lib/libc/string/wmemchr.c
+++ b/libc/upstream-freebsd/lib/libc/string/wmemchr.c
@@ -34,7 +34,7 @@
 __RCSID("$NetBSD: wmemchr.c,v 1.1 2000/12/23 23:14:37 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wmemchr.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wmemcmp.c b/libc/upstream-freebsd/lib/libc/string/wmemcmp.c
index c1e9f3c..f1b1b00 100644
--- a/libc/upstream-freebsd/lib/libc/string/wmemcmp.c
+++ b/libc/upstream-freebsd/lib/libc/string/wmemcmp.c
@@ -34,7 +34,7 @@
 __RCSID("$NetBSD: wmemcmp.c,v 1.1 2000/12/23 23:14:37 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wmemcmp.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-freebsd/lib/libc/string/wmemcpy.c b/libc/upstream-freebsd/lib/libc/string/wmemcpy.c
index e0d6c04..30956eb 100644
--- a/libc/upstream-freebsd/lib/libc/string/wmemcpy.c
+++ b/libc/upstream-freebsd/lib/libc/string/wmemcpy.c
@@ -34,7 +34,7 @@
 __RCSID("$NetBSD: wmemcpy.c,v 1.1 2000/12/23 23:14:37 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wmemcpy.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <string.h>
 #include <wchar.h>
diff --git a/libc/upstream-freebsd/lib/libc/string/wmemmove.c b/libc/upstream-freebsd/lib/libc/string/wmemmove.c
index b84c2c0..5e8da9f 100644
--- a/libc/upstream-freebsd/lib/libc/string/wmemmove.c
+++ b/libc/upstream-freebsd/lib/libc/string/wmemmove.c
@@ -34,7 +34,7 @@
 __RCSID("$NetBSD: wmemmove.c,v 1.1 2000/12/23 23:14:37 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wmemmove.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <string.h>
 #include <wchar.h>
diff --git a/libc/upstream-freebsd/lib/libc/string/wmemset.c b/libc/upstream-freebsd/lib/libc/string/wmemset.c
index d4d6308..fcf40ef 100644
--- a/libc/upstream-freebsd/lib/libc/string/wmemset.c
+++ b/libc/upstream-freebsd/lib/libc/string/wmemset.c
@@ -34,7 +34,7 @@
 __RCSID("$NetBSD: wmemset.c,v 1.1 2000/12/23 23:14:37 itojun Exp $");
 #endif /* LIBC_SCCS and not lint */
 #endif
-__FBSDID("$FreeBSD: head/lib/libc/string/wmemset.c 326193 2017-11-25 17:12:48Z pfg $");
+__FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
diff --git a/libc/upstream-netbsd/android/include/rand48.h b/libc/upstream-netbsd/lib/libc/stdlib/rand48.h
similarity index 80%
rename from libc/upstream-netbsd/android/include/rand48.h
rename to libc/upstream-netbsd/lib/libc/stdlib/rand48.h
index 1279906..1ad8b0d 100644
--- a/libc/upstream-netbsd/android/include/rand48.h
+++ b/libc/upstream-netbsd/lib/libc/stdlib/rand48.h
@@ -18,10 +18,10 @@
 
 #include <stdlib.h>
 
-__LIBC_HIDDEN__ void		__dorand48(unsigned short[3]);
-__LIBC_HIDDEN__ unsigned short	__rand48_seed[3];
-__LIBC_HIDDEN__ unsigned short	__rand48_mult[3];
-__LIBC_HIDDEN__ unsigned short	__rand48_add;
+extern void		__dorand48(unsigned short[3]);
+extern unsigned short	__rand48_seed[3];
+extern unsigned short	__rand48_mult[3];
+extern unsigned short	__rand48_add;
 
 #define	RAND48_SEED_0	(0x330e)
 #define	RAND48_SEED_1	(0xabcd)
diff --git a/tests/run-on-host.sh b/tests/run-on-host.sh
index fe2c25a..19bbacf 100755
--- a/tests/run-on-host.sh
+++ b/tests/run-on-host.sh
@@ -2,9 +2,14 @@
 
 . $(dirname $0)/../build/run-on-host.sh
 
-if [ "$1" = glibc ]; then
+if [ "$1" = glibc -o "$1" = musl ]; then
+  if [ "$1" = musl ]; then
+    BUILD_ARGS=USE_HOST_MUSL=true
+  else
+    BUILD_ARGS=
+  fi
   shift
-  m -j bionic-unit-tests-glibc
+  m -j $BUILD_ARGS bionic-unit-tests-glibc
   (
     cd ${ANDROID_BUILD_TOP}
     export ANDROID_DATA=${TARGET_OUT_DATA}
@@ -13,7 +18,7 @@
   )
   exit 0
 elif [ "$1" != 32 -a "$1" != 64 ]; then
-  echo "Usage: $0 [ 32 | 64 | glibc ] [gtest flags]"
+  echo "Usage: $0 [ 32 | 64 | glibc | musl ] [gtest flags]"
   exit 1
 fi
 
diff --git a/tests/uchar_test.cpp b/tests/uchar_test.cpp
index 4dc6314..d7174bd 100644
--- a/tests/uchar_test.cpp
+++ b/tests/uchar_test.cpp
@@ -24,6 +24,47 @@
 #include <locale.h>
 #include <stdint.h>
 
+// Modern versions of UTF-8 (https://datatracker.ietf.org/doc/html/rfc3629 and
+// newer) explicitly disallow code points beyond U+10FFFF, which exclude all 5-
+// and 6-byte sequences. Earlier versions of UTF-8 allowed the wider range:
+// https://datatracker.ietf.org/doc/html/rfc2279.
+//
+// Bionic's unicode implementation was written after the high values were
+// excluded, so it has never supported them. Other implementations (at least
+// as of glibc 2.36), do support those sequences.
+#if defined(__ANDROID__) || defined(ANDROID_HOST_MUSL)
+constexpr bool kLibcRejectsOverLongUtf8Sequences = true;
+#elif defined(__GLIBC__)
+constexpr bool kLibcRejectsOverLongUtf8Sequences = false;
+#else
+#error kLibcRejectsOverLongUtf8Sequences must be configured for this platform
+#endif
+
+// C23 7.30.1 (for each `mbrtoc*` function) says:
+//
+// Returns:
+//
+//     0 if the next n or fewer bytes complete the multibyte character that
+//     corresponds to the null wide character (which is the value stored).
+//
+//     (size_t)(-2) if the next n bytes contribute to an incomplete (but
+//     potentially valid) multibyte character, and all n bytes have been
+//     processed (no value is stored).
+//
+// Bionic historically interpreted the behavior when n is 0 to be the next 0
+// bytes decoding to the null. That's a pretty bad interpretation, and both
+// glibc and musl return -2 for that case.
+//
+// The tests currently checks the incorrect behavior for bionic because gtest
+// doesn't support explicit xfail annotations. The behavior difference here
+// should be fixed, but danalbert wants to add more tests before tackling the
+// bugs.
+#ifdef __ANDROID__
+constexpr size_t kExpectedResultForZeroLength = 0U;
+#else
+constexpr size_t kExpectedResultForZeroLength = static_cast<size_t>(-2);
+#endif
+
 TEST(uchar, sizeof_uchar_t) {
   EXPECT_EQ(2U, sizeof(char16_t));
   EXPECT_EQ(4U, sizeof(char32_t));
@@ -116,13 +157,13 @@
   char16_t out;
 
   out = L'x';
-  ASSERT_EQ(0U, mbrtoc16(&out, "hello", 0, nullptr));
-  ASSERT_EQ(L'x', out);
+  EXPECT_EQ(kExpectedResultForZeroLength, mbrtoc16(&out, "hello", 0, nullptr));
+  EXPECT_EQ(L'x', out);
 
-  ASSERT_EQ(0U, mbrtoc16(&out, "hello", 0, nullptr));
-  ASSERT_EQ(0U, mbrtoc16(&out, "", 0, nullptr));
-  ASSERT_EQ(1U, mbrtoc16(&out, "hello", 1, nullptr));
-  ASSERT_EQ(L'h', out);
+  EXPECT_EQ(kExpectedResultForZeroLength, mbrtoc16(&out, "hello", 0, nullptr));
+  EXPECT_EQ(kExpectedResultForZeroLength, mbrtoc16(&out, "", 0, nullptr));
+  EXPECT_EQ(1U, mbrtoc16(&out, "hello", 1, nullptr));
+  EXPECT_EQ(L'h', out);
 }
 
 TEST(uchar, mbrtoc16) {
@@ -146,10 +187,24 @@
   ASSERT_EQ(static_cast<char16_t>(0xdbea), out);
   ASSERT_EQ(4U, mbrtoc16(&out, "\xf4\x8a\xaf\x8d" "ef", 6, nullptr));
   ASSERT_EQ(static_cast<char16_t>(0xdfcd), out);
-  // Illegal 5-byte UTF-8.
+}
+
+TEST(uchar, mbrtoc16_long_sequences) {
+  ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
+  uselocale(LC_GLOBAL_LOCALE);
+
+  char16_t out = u'\0';
   errno = 0;
-  ASSERT_EQ(static_cast<size_t>(-1), mbrtoc16(&out, "\xf8\xa1\xa2\xa3\xa4", 5, nullptr));
-  ASSERT_EQ(EILSEQ, errno);
+  auto result = mbrtoc16(&out, "\xf8\xa1\xa2\xa3\xa4", 5, nullptr);
+  if (kLibcRejectsOverLongUtf8Sequences) {
+    EXPECT_EQ(static_cast<size_t>(-1), result);
+    EXPECT_EQ(EILSEQ, errno);
+    EXPECT_EQ(u'\0', out);
+  } else {
+    EXPECT_EQ(5U, result);
+    EXPECT_EQ(0, errno);
+    EXPECT_EQ(u'\uf94a', out);
+  }
 }
 
 TEST(uchar, mbrtoc16_reserved_range) {
@@ -265,55 +320,78 @@
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);
 
-  char32_t out[8] = {};
+  char32_t out = U'\0';
   errno = 0;
-  ASSERT_EQ(static_cast<size_t>(-1), mbrtoc32(out, "\xf5\x80\x80\x80", 4, nullptr));
-  ASSERT_EQ(EILSEQ, errno);
+  auto result = mbrtoc32(&out, "\xf5\x80\x80\x80", 4, nullptr);
+  if (kLibcRejectsOverLongUtf8Sequences) {
+    EXPECT_EQ(static_cast<size_t>(-1), result);
+    EXPECT_EQ(EILSEQ, errno);
+    EXPECT_EQ(U'\0', out);
+  } else {
+    EXPECT_EQ(4U, result);
+    EXPECT_EQ(0, errno);
+    EXPECT_EQ(U'\x140000', out);
+  }
 }
 
 TEST(uchar, mbrtoc32) {
   char32_t out[8];
 
   out[0] = L'x';
-  ASSERT_EQ(0U, mbrtoc32(out, "hello", 0, nullptr));
-  ASSERT_EQ(static_cast<char32_t>(L'x'), out[0]);
+  EXPECT_EQ(kExpectedResultForZeroLength, mbrtoc32(out, "hello", 0, nullptr));
+  EXPECT_EQ(static_cast<char32_t>(L'x'), out[0]);
 
-  ASSERT_EQ(0U, mbrtoc32(out, "hello", 0, nullptr));
-  ASSERT_EQ(0U, mbrtoc32(out, "", 0, nullptr));
-  ASSERT_EQ(1U, mbrtoc32(out, "hello", 1, nullptr));
-  ASSERT_EQ(static_cast<char32_t>(L'h'), out[0]);
+  EXPECT_EQ(kExpectedResultForZeroLength, mbrtoc32(out, "hello", 0, nullptr));
+  EXPECT_EQ(kExpectedResultForZeroLength, mbrtoc32(out, "", 0, nullptr));
+  EXPECT_EQ(1U, mbrtoc32(out, "hello", 1, nullptr));
+  EXPECT_EQ(static_cast<char32_t>(L'h'), out[0]);
 
-  ASSERT_EQ(0U, mbrtoc32(nullptr, "hello", 0, nullptr));
-  ASSERT_EQ(0U, mbrtoc32(nullptr, "", 0, nullptr));
-  ASSERT_EQ(1U, mbrtoc32(nullptr, "hello", 1, nullptr));
+  EXPECT_EQ(kExpectedResultForZeroLength, mbrtoc32(nullptr, "hello", 0, nullptr));
+  EXPECT_EQ(kExpectedResultForZeroLength, mbrtoc32(nullptr, "", 0, nullptr));
+  EXPECT_EQ(1U, mbrtoc32(nullptr, "hello", 1, nullptr));
 
-  ASSERT_EQ(0U, mbrtoc32(nullptr, nullptr, 0, nullptr));
+  EXPECT_EQ(0U, mbrtoc32(nullptr, nullptr, 0, nullptr));
 
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);
 
   // 1-byte UTF-8.
-  ASSERT_EQ(1U, mbrtoc32(out, "abcdef", 6, nullptr));
-  ASSERT_EQ(static_cast<char32_t>(L'a'), out[0]);
+  EXPECT_EQ(1U, mbrtoc32(out, "abcdef", 6, nullptr));
+  EXPECT_EQ(static_cast<char32_t>(L'a'), out[0]);
   // 2-byte UTF-8.
-  ASSERT_EQ(2U, mbrtoc32(out, "\xc2\xa2" "cdef", 6, nullptr));
-  ASSERT_EQ(static_cast<char32_t>(0x00a2), out[0]);
+  EXPECT_EQ(2U, mbrtoc32(out,
+                         "\xc2\xa2"
+                         "cdef",
+                         6, nullptr));
+  EXPECT_EQ(static_cast<char32_t>(0x00a2), out[0]);
   // 3-byte UTF-8.
-  ASSERT_EQ(3U, mbrtoc32(out, "\xe2\x82\xac" "def", 6, nullptr));
-  ASSERT_EQ(static_cast<char32_t>(0x20ac), out[0]);
+  EXPECT_EQ(3U, mbrtoc32(out,
+                         "\xe2\x82\xac"
+                         "def",
+                         6, nullptr));
+  EXPECT_EQ(static_cast<char32_t>(0x20ac), out[0]);
   // 4-byte UTF-8.
-  ASSERT_EQ(4U, mbrtoc32(out, "\xf0\xa4\xad\xa2" "ef", 6, nullptr));
-  ASSERT_EQ(static_cast<char32_t>(0x24b62), out[0]);
+  EXPECT_EQ(4U, mbrtoc32(out,
+                         "\xf0\xa4\xad\xa2"
+                         "ef",
+                         6, nullptr));
+  EXPECT_EQ(static_cast<char32_t>(0x24b62), out[0]);
 #if defined(__BIONIC__) // glibc allows this.
   // Illegal 5-byte UTF-8.
   errno = 0;
-  ASSERT_EQ(static_cast<size_t>(-1), mbrtoc32(out, "\xf8\xa1\xa2\xa3\xa4" "f", 6, nullptr));
-  ASSERT_EQ(EILSEQ, errno);
+  EXPECT_EQ(static_cast<size_t>(-1), mbrtoc32(out,
+                                              "\xf8\xa1\xa2\xa3\xa4"
+                                              "f",
+                                              6, nullptr));
+  EXPECT_EQ(EILSEQ, errno);
 #endif
   // Illegal over-long sequence.
   errno = 0;
-  ASSERT_EQ(static_cast<size_t>(-1), mbrtoc32(out, "\xf0\x82\x82\xac" "ef", 6, nullptr));
-  ASSERT_EQ(EILSEQ, errno);
+  EXPECT_EQ(static_cast<size_t>(-1), mbrtoc32(out,
+                                              "\xf0\x82\x82\xac"
+                                              "ef",
+                                              6, nullptr));
+  EXPECT_EQ(EILSEQ, errno);
 }
 
 void test_mbrtoc32_incomplete(mbstate_t* ps) {