getlogin on mingw

[Bruno Haible]

I'm seeing this compilation failure on a recent mingw:

In file included from ../../gltests/test-getlogin.c:23:0:
../../gltests/test-getlogin.c:24:18: error: ‘getlogin’ undeclared here (not in 
a function)
 SIGNATURE_CHECK (getlogin, char *, (void));
                  ^
../../gltests/signature.h:46:58: note: in definition of macro ‘SIGNATURE_CHECK2’
   static ret (* _GL_UNUSED signature_check ## id) args = fn
                                                          ^
../../gltests/signature.h:39:3: note: in expansion of macro ‘SIGNATURE_CHECK1’
   SIGNATURE_CHECK1 (fn, ret, args, __LINE__)
   ^
../../gltests/test-getlogin.c:24:1: note: in expansion of macro 
‘SIGNATURE_CHECK’
 SIGNATURE_CHECK (getlogin, char *, (void));
 ^
../../gltests/test-getlogin.c:31:17: fatal error: pwd.h: No such file or 
directory
compilation terminated.
make[4]: *** [Makefile:7987: test-getlogin.o] Error 1

The reason is that getlogin exists, but is only declared in <io.h> and only
with -D_POSIX, which I'd prefer to not turn on. And a regression from 
2014-05-14.
This fixes it.


2016-12-17  Bruno Haible  <address@hidden>

        getlogin: Port to newer mingw.
        * m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Initialize HAVE_DECL_GETLOGIN.
        * m4/getlogin.m4 (gl_FUNC_GETLOGIN): Set HAVE_DECL_GETLOGIN.
        * modules/unistd (Makefile.am): Substibute HAVE_DECL_GETLOGIN, not
        HAVE_GETLOGIN.
        * lib/unistd.in.h (getlogin): Test HAVE_DECL_GETLOGIN, not
        HAVE_GETLOGIN.
        * doc/posix-functions/getlogin.texi: Mention the issue.
        * tests/test-getlogin.c: Don't include <pwd.h> on native Windows. Fixes
        regression introduced on 2014-05-14.

diff --git a/doc/posix-functions/getlogin.texi 
b/doc/posix-functions/getlogin.texi
index 2569eb1..73e961c 100644
--- a/doc/posix-functions/getlogin.texi
+++ b/doc/posix-functions/getlogin.texi
@@ -10,7 +10,10 @@ Portability problems fixed by Gnulib:
 @itemize
 @item
 This function is missing on some platforms:
-mingw, MSVC 9.
+older mingw, MSVC 9.
address@hidden
+This function is not declared unless @code{_POSIX} is defined on some 
platforms:
+mingw.
 @end itemize
 
 Portability problems not fixed by Gnulib:
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index 61250c9..686eb81 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -776,7 +776,7 @@ _GL_WARN_ON_USE (gethostname, "gethostname is unportable - "
      ${LOGNAME-$USER}        on Unix platforms,
      $USERNAME               on native Windows platforms.
  */
-# if address@hidden@
+# if address@hidden@
 _GL_FUNCDECL_SYS (getlogin, char *, (void));
 # endif
 _GL_CXXALIAS_SYS (getlogin, char *, (void));
diff --git a/m4/getlogin.m4 b/m4/getlogin.m4
index b3b2655..a03193b 100644
--- a/m4/getlogin.m4
+++ b/m4/getlogin.m4
@@ -1,4 +1,4 @@
-# getlogin.m4 serial 3
+# getlogin.m4 serial 4
 dnl Copyright (C) 2010-2016 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,6 +7,10 @@ dnl with or without modifications, as long as this notice is 
preserved.
 AC_DEFUN([gl_FUNC_GETLOGIN],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_CHECK_DECLS_ONCE([getlogin])
+  if test $ac_cv_have_decl_getlogin = no; then
+    HAVE_DECL_GETLOGIN=0
+  fi
   AC_CHECK_FUNCS_ONCE([getlogin])
   if test $ac_cv_func_getlogin = no; then
     HAVE_GETLOGIN=0
diff --git a/m4/unistd_h.m4 b/m4/unistd_h.m4
index 544dadb..46ff109 100644
--- a/m4/unistd_h.m4
+++ b/m4/unistd_h.m4
@@ -1,4 +1,4 @@
-# unistd_h.m4 serial 68
+# unistd_h.m4 serial 69
 dnl Copyright (C) 2006-2016 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -145,6 +145,7 @@ AC_DEFUN([gl_UNISTD_H_DEFAULTS],
   HAVE_DECL_FCHDIR=1;     AC_SUBST([HAVE_DECL_FCHDIR])
   HAVE_DECL_FDATASYNC=1;  AC_SUBST([HAVE_DECL_FDATASYNC])
   HAVE_DECL_GETDOMAINNAME=1; AC_SUBST([HAVE_DECL_GETDOMAINNAME])
+  HAVE_DECL_GETLOGIN=1;   AC_SUBST([HAVE_DECL_GETLOGIN])
   HAVE_DECL_GETLOGIN_R=1; AC_SUBST([HAVE_DECL_GETLOGIN_R])
   HAVE_DECL_GETPAGESIZE=1; AC_SUBST([HAVE_DECL_GETPAGESIZE])
   HAVE_DECL_GETUSERSHELL=1; AC_SUBST([HAVE_DECL_GETUSERSHELL])
diff --git a/modules/unistd b/modules/unistd
index 1619509..8af837c 100644
--- a/modules/unistd
+++ b/modules/unistd
@@ -99,7 +99,6 @@ unistd.h: unistd.in.h $(top_builddir)/config.status 
$(CXXDEFS_H) $(ARG_NONNULL_H
              -e 's|@''HAVE_GETDTABLESIZE''@|$(HAVE_GETDTABLESIZE)|g' \
              -e 's|@''HAVE_GETGROUPS''@|$(HAVE_GETGROUPS)|g' \
              -e 's|@''HAVE_GETHOSTNAME''@|$(HAVE_GETHOSTNAME)|g' \
-             -e 's|@''HAVE_GETLOGIN''@|$(HAVE_GETLOGIN)|g' \
              -e 's|@''HAVE_GETPAGESIZE''@|$(HAVE_GETPAGESIZE)|g' \
              -e 's|@''HAVE_GROUP_MEMBER''@|$(HAVE_GROUP_MEMBER)|g' \
              -e 's|@''HAVE_LCHOWN''@|$(HAVE_LCHOWN)|g' \
@@ -121,6 +120,7 @@ unistd.h: unistd.in.h $(top_builddir)/config.status 
$(CXXDEFS_H) $(ARG_NONNULL_H
              -e 's|@''HAVE_DECL_FCHDIR''@|$(HAVE_DECL_FCHDIR)|g' \
              -e 's|@''HAVE_DECL_FDATASYNC''@|$(HAVE_DECL_FDATASYNC)|g' \
              -e 's|@''HAVE_DECL_GETDOMAINNAME''@|$(HAVE_DECL_GETDOMAINNAME)|g' 
\
+             -e 's|@''HAVE_DECL_GETLOGIN''@|$(HAVE_DECL_GETLOGIN)|g' \
              -e 's|@''HAVE_DECL_GETLOGIN_R''@|$(HAVE_DECL_GETLOGIN_R)|g' \
              -e 's|@''HAVE_DECL_GETPAGESIZE''@|$(HAVE_DECL_GETPAGESIZE)|g' \
              -e 's|@''HAVE_DECL_GETUSERSHELL''@|$(HAVE_DECL_GETUSERSHELL)|g' \
diff --git a/tests/test-getlogin.c b/tests/test-getlogin.c
index 6e1b64c..ed04c8c 100644
--- a/tests/test-getlogin.c
+++ b/tests/test-getlogin.c
@@ -28,7 +28,9 @@ SIGNATURE_CHECK (getlogin, char *, (void));
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-#include <pwd.h>
+#if !((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__)
+# include <pwd.h>
+#endif
 
 #include <sys/stat.h>
 #include <sys/types.h>