sh-filename: Add support for Android

[Bruno Haible]

On Android 4.3, I'm seeing these test failures:

FAIL: test-posix_spawn1
=======================

could not read expected output
FAIL test-posix_spawn1 (exit status: 1)

FAIL: test-posix_spawn2
=======================

subprocess terminated with unexpected exit status 127
FAIL test-posix_spawn2 (exit status: 1)

The cause is that these tests execute a shell script, and the shell
is not at /bin/sh in this environment.

This patch fixes it.


2019-01-26  Bruno Haible  <address@hidden>

        sh-filename: Add support for Android 4.3.
        * m4/sh-filename.m4 (gl_SH_FILENAME): Set to "sh" on Android.

diff --git a/m4/sh-filename.m4 b/m4/sh-filename.m4
index 3e7fe75..dc5f26d 100644
--- a/m4/sh-filename.m4
+++ b/m4/sh-filename.m4
@@ -1,4 +1,4 @@
-# sh-filename.m4 serial 1
+# sh-filename.m4 serial 2
 dnl Copyright (C) 2018-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -10,9 +10,11 @@ AC_DEFUN([gl_SH_FILENAME],
 [
   AH_VERBATIM([SH_FILENAME],
 [/* File name of the Bourne shell.  */
-#if defined __CYGWIN__
-/* Omit the directory part because for 32-bit Cygwin programs in a
-   64-bit Cygwin environment, the Cygwin mounts are not visible.  */
+#if defined __CYGWIN__ || defined __ANDROID__
+/* Omit the directory part because
+   - For 32-bit Cygwin programs in a 64-bit Cygwin environment, the Cygwin
+     mounts are not visible.
+   - On Android, /bin/sh does not exist. It's /system/bin/sh instead.  */
 # define BOURNE_SHELL "sh"
 #else
 # define BOURNE_SHELL "/bin/sh"