fdopendir: Fix fd leak and test failure on native Windows.

* lib/dirent-private.h: On mingw, define 'struct gl_directory' as a
wrapper around the original DIR. On MSVC, add an 'fd_to_close' field to
'struct gl_directory'.
* lib/dirent.in.h (DIR): Define when DIR_HAS_FD_MEMBER is 0, i.e. on
both mingw and MSVC.
(GNULIB_defined_DIR): New macro.
(opendir): Avoid incompatible redeclaration.
(readdir): Consider REPLACE_READDIR.
(rewinddir): Consider REPLACE_REWINDDIR.
* m4/dirent_h.m4 (gl_DIRENT_DIR): New macro.
(gl_DIRENT_H): Invoke it.
(gl_DIRENT_H_DEFAULTS): Initialize REPLACE_READDIR, REPLACE_REWINDDIR.
* modules/dirent (Makefile.am): Substitute DIR_HAS_FD_MEMBER,
REPLACE_READDIR, REPLACE_REWINDDIR.
--
* lib/dirfd.c (dirfd): If GNULIB_defined_DIR, just use the
'fd_to_close' field.
* m4/dirfd.m4 (gl_FUNC_DIRFD): Set HAVE_DIRFD. Don't set REPLACE_DIRFD
to 1 if HAVE_DIRFD is 0. If DIR_HAS_FD_MEMBER is 0, ensure dirfd.c gets
compiled.
* modules/dirfd (Files): Add lib/dirent-private.h.
(Depends-on, configure.ac): Simplify conditions.
--
* lib/closedir.c: Include <stdlib.h> always, for free().
(closedir): If GNULIB_defined_DIR, arrange to call close(dirfd(dirp)) at
the end. On mingw, call free() of dirp. Prefer testing HAVE_DIRENT_H,
for consistency with dirent.h.
* m4/closedir.m4 (gl_FUNC_CLOSEDIR): Don't set REPLACE_CLOSEDIR to 1 if
HAVE_CLOSEDIR is 0. If DIR_HAS_FD_MEMBER is 0, ensure closedir.c gets
compiled.
--
* lib/opendir.c: Include <stdlib.h> always. Include <string.h>.
(opendir): On mingw, allocate the 'struct gl_directory' through malloc.
If GNULIB_defined_DIR, set the 'fd_to_close' field to -1. Prefer
testing HAVE_DIRENT_H, for consistency with dirent.h.
* m4/opendir.m4 (gl_FUNC_OPENDIR): Don't set REPLACE_OPENDIR to 1 if
HAVE_OPENDIR is 0. If DIR_HAS_FD_MEMBER is 0, ensure opendir.c gets
compiled.
--
* lib/fdopendir.c (fdopendir): If GNULIB_defined_DIR, use a simple
implementation based on opendir and the fchdir module. If __KLIBC__,
don't define unused auxiliary functions.
* modules/fdopendir (Files): Add lib/dirent-private.h.
--
* lib/readdir.c (readdir): On mingw, redirect to the original readdir
function. Prefer testing HAVE_DIRENT_H, for consistency with dirent.h.
* m4/readdir.m4 (gl_FUNC_READDIR): If DIR_HAS_FD_MEMBER is 0, ensure
readdir.c gets compiled.
* modules/readdir (configure.ac): Consider REPLACE_READDIR.
--
* lib/rewinddir.c (rewinddir): On mingw, redirect to the original
rewinddir function. Prefer testing HAVE_DIRENT_H, for consistency with
dirent.h.
* m4/rewinddir.m4 (gl_FUNC_REWINDDIR): If DIR_HAS_FD_MEMBER is 0, ensure
rewinddir.c gets compiled.
* modules/rewinddir (configure.ac): Consider REPLACE_REWINDDIR.
--
* lib/fchdir.c (dir_info_t): Remove a FIXME.

1 files changed, 19 insertions, 16 deletions

diff --git a/m4/opendir.m4 b/m4/opendir.m4
index 2fb90b6d57..2e9be769b5 100644
--- a/m4/opendir.m4
+++ b/m4/opendir.m4
@@ -1,4 +1,4 @@
-# opendir.m4 serial 5
+# opendir.m4 serial 6
 dnl Copyright (C) 2011-2023 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -12,21 +12,24 @@ AC_DEFUN([gl_FUNC_OPENDIR],
   AC_CHECK_FUNCS([opendir])
   if test $ac_cv_func_opendir = no; then
     HAVE_OPENDIR=0
-  fi
-  dnl Replace opendir() for supporting the gnulib-defined fchdir() function,
-  dnl to keep fchdir's bookkeeping up-to-date.
-  m4_ifdef([gl_FUNC_FCHDIR], [
-    gl_TEST_FCHDIR
-    if test $HAVE_FCHDIR = 0; then
-      if test $HAVE_OPENDIR = 1; then
+  else
+    dnl Replace opendir() on native Windows, to support fdopendir().
+    AC_REQUIRE([gl_DIRENT_DIR])
+    if test $DIR_HAS_FD_MEMBER = 0; then
+      REPLACE_OPENDIR=1
+    fi
+    dnl Replace opendir() on OS/2 kLIBC to support dirfd() function replaced
+    dnl by gnulib.
+    case $host_os in
+      os2*) REPLACE_OPENDIR=1 ;;
+    esac
+    dnl Replace opendir() for supporting the gnulib-defined fchdir() function,
+    dnl to keep fchdir's bookkeeping up-to-date.
+    m4_ifdef([gl_FUNC_FCHDIR], [
+      gl_TEST_FCHDIR
+      if test $HAVE_FCHDIR = 0; then
         REPLACE_OPENDIR=1
       fi
-    fi
-  ])
-  dnl Replace opendir() on OS/2 kLIBC to support dirfd() function replaced
-  dnl by gnulib.
-  case $host_os,$HAVE_OPENDIR in
-    os2*,1)
-      REPLACE_OPENDIR=1;;
-  esac
+    ])
+  fi
 ])