Paul Eggert wrote:
> In the meantime I installed the attached to Gnulib, to
> document the incompatibility, which also occurs with getlogin_r.
These two patches actually work around the bugs.
With this, coreutils should be fine, since it already imports the 'getlogin'
module from gnulib.
2025-03-09 Bruno Haible <br...@clisp.org>
getlogin_r: Work around musl bug.
* lib/getlogin_r.c (getlogin_r): Add implementation for Linux.
* m4/getlogin_r.m4 (gl_FUNC_GETLOGIN_R): Test whether getlogin_r has the
musl bug.
* tests/test-getlogin_r.c (main): Add another test.
* doc/posix-functions/getlogin_r.texi: Mention the workaround.
2025-03-09 Bruno Haible <br...@clisp.org>
getlogin: Work around musl bug.
* lib/unistd.in.h (getlogin): Consider REPLACE_GETLOGIN.
* lib/getlogin.c: Change license header to GPL.
(getlogin): Add implementation for Linux.
* m4/getlogin.m4 (gl_FUNC_GETLOGIN): Test whether getlogin works.
* m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Initialize REPLACE_GETLOGIN.
* modules/unistd-h (Makefile.am): Substitute REPLACE_GETLOGIN.
* modules/getlogin (Depends-on): Add readutmp.
(configure.ac): Consider REPLACE_GETLOGIN.
(License): Change to GPL.
* tests/test-getlogin.c (main): Add another test.
* doc/posix-functions/getlogin.texi: Mention the workaround.
>From 90840606e77dd24d87ad7f075d8f87c0ed814ef5 Mon Sep 17 00:00:00 2001
From: Bruno Haible <br...@clisp.org>
Date: Sun, 9 Mar 2025 10:16:58 +0100
Subject: [PATCH 1/2] getlogin: Work around musl bug.
* lib/unistd.in.h (getlogin): Consider REPLACE_GETLOGIN.
* lib/getlogin.c: Change license header to GPL.
(getlogin): Add implementation for Linux.
* m4/getlogin.m4 (gl_FUNC_GETLOGIN): Test whether getlogin works.
* m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Initialize REPLACE_GETLOGIN.
* modules/unistd-h (Makefile.am): Substitute REPLACE_GETLOGIN.
* modules/getlogin (Depends-on): Add readutmp.
(configure.ac): Consider REPLACE_GETLOGIN.
(License): Change to GPL.
* tests/test-getlogin.c (main): Add another test.
* doc/posix-functions/getlogin.texi: Mention the workaround.
---
ChangeLog | 15 +++++
doc/posix-functions/getlogin.texi | 6 +-
lib/getlogin.c | 99 +++++++++++++++++++++++++++++--
lib/unistd.in.h | 14 ++++-
m4/getlogin.m4 | 49 ++++++++++++++-
m4/unistd_h.m4 | 3 +-
modules/getlogin | 6 +-
modules/unistd-h | 1 +
tests/test-getlogin.c | 6 ++
9 files changed, 184 insertions(+), 15 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 89940ddd4c..6d2ad66c83 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+2025-03-09 Bruno Haible <br...@clisp.org>
+
+ getlogin: Work around musl bug.
+ * lib/unistd.in.h (getlogin): Consider REPLACE_GETLOGIN.
+ * lib/getlogin.c: Change license header to GPL.
+ (getlogin): Add implementation for Linux.
+ * m4/getlogin.m4 (gl_FUNC_GETLOGIN): Test whether getlogin works.
+ * m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Initialize REPLACE_GETLOGIN.
+ * modules/unistd-h (Makefile.am): Substitute REPLACE_GETLOGIN.
+ * modules/getlogin (Depends-on): Add readutmp.
+ (configure.ac): Consider REPLACE_GETLOGIN.
+ (License): Change to GPL.
+ * tests/test-getlogin.c (main): Add another test.
+ * doc/posix-functions/getlogin.texi: Mention the workaround.
+
2025-03-08 Paul Eggert <egg...@cs.ucla.edu>
getlogin: document musl bug
diff --git a/doc/posix-functions/getlogin.texi b/doc/posix-functions/getlogin.texi
index 0de026f2ee..0ccce336ce 100644
--- a/doc/posix-functions/getlogin.texi
+++ b/doc/posix-functions/getlogin.texi
@@ -15,14 +15,14 @@
@item
This function is not declared unless @code{_POSIX} is defined on some platforms:
mingw.
+@item
+This function returns the value of the @env{LOGNAME} environment variable:
+musl libc 1.2.5.
@end itemize
Portability problems not fixed by Gnulib:
@itemize
@item
-This function returns the value of the @env{LOGNAME} environment variable:
-musl libc 1.2.5.
-@item
This function returns an empty string even when standard input is a tty
on some platforms:
HP-UX 11.11.
diff --git a/lib/getlogin.c b/lib/getlogin.c
index 72c25acbc7..4772111567 100644
--- a/lib/getlogin.c
+++ b/lib/getlogin.c
@@ -3,19 +3,19 @@
Copyright (C) 2010-2025 Free Software Foundation, Inc.
This file is free software: you can redistribute it and/or modify
- it under the terms of the GNU Lesser General Public License as
- published by the Free Software Foundation; either version 2.1 of the
- License, or (at your option) any later version.
+ it under the terms of the GNU General Public License as published
+ by the Free Software Foundation, either version 3 of the License,
+ or (at your option) any later version.
This file is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU Lesser General Public License for more details.
+ GNU General Public License for more details.
- You should have received a copy of the GNU Lesser General Public License
+ You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
-/* Written by Bruno Haible, 2010. */
+/* Written by Bruno Haible, 2010, 2025. */
#include <config.h>
@@ -30,15 +30,102 @@
# define GetUserName GetUserNameA
#endif
+#if defined __linux__ || defined __ANDROID__
+# include <fcntl.h>
+# include <pwd.h>
+# include <stdlib.h>
+# include <string.h>
+# include <sys/stat.h>
+# include "readutmp.h"
+#endif
+
char *
getlogin (void)
{
#if defined _WIN32 && ! defined __CYGWIN__
+ /* Native Windows platform. */
static char login_name[1024];
DWORD sz = sizeof (login_name);
if (GetUserName (login_name, &sz))
return login_name;
+#elif defined __linux__ || defined __ANDROID__
+ /* Linux. */
+ {
+ /* Read the login uid from the /proc file system. */
+ int fd = open ("/proc/self/loginuid", O_RDONLY);
+ if (fd >= 0)
+ {
+ char buf[20 + 1];
+ int n = read (fd, buf, sizeof (buf) - 1);
+ if (n > 0)
+ {
+ buf[n] = '\0';
+ char *endptr;
+ unsigned long uid = strtoul (buf, &endptr, 10);
+ if (endptr == buf + n && uid != (uid_t) -1)
+ {
+ /* Convert the uid to a user name. */
+ struct passwd *p = getpwuid (uid);
+ if (p != NULL && strlen (p->pw_name) < 64)
+ {
+ static char resultbuf[64];
+ strcpy (resultbuf, p->pw_name);
+ close (fd);
+ return resultbuf;
+ }
+ }
+ }
+ close (fd);
+ }
+ }
+ {
+ /* Find the tty connected to the current process. */
+ char *tty = ttyname (STDIN_FILENO);
+ if (tty != NULL)
+ {
+ /* Try to see to which user it is allocated, via utmp. */
+ if (strncmp (tty, "/dev/tty", 8) == 0)
+ {
+ idx_t n;
+ STRUCT_UTMP *entries;
+ if (read_utmp (UTMP_FILE, &n, &entries, READ_UTMP_USER_PROCESS)
+ == 0)
+ {
+ idx_t i;
+ for (i = 0; i < n; i++)
+ if (strcmp (entries[i].ut_line, tty + 5) == 0)
+ {
+ if (strlen (entries[i].ut_user) < 64)
+ {
+ static char resultbuf[64];
+ strcpy (resultbuf, entries[i].ut_user);
+ free (entries);
+ return resultbuf;
+ }
+ break;
+ }
+ free (entries);
+ }
+ }
+ /* Fallback for systems which don't maintain an utmp database
+ or for ttys that are not recorded in that the utmp database:
+ Look at the owner of that tty. */
+ struct stat statbuf;
+ if (stat (tty, &statbuf) >= 0)
+ {
+ uid_t uid = statbuf.st_uid;
+ /* Convert the uid to a user name. */
+ struct passwd *p = getpwuid (uid);
+ if (p != NULL && strlen (p->pw_name) < 64)
+ {
+ static char resultbuf[64];
+ strcpy (resultbuf, p->pw_name);
+ return resultbuf;
+ }
+ }
+ }
+ }
#endif
return NULL;
}
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index acabdf8c68..bfb4817726 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -1365,11 +1365,21 @@ _GL_WARN_ON_USE (gethostname, "gethostname is unportable - "
${LOGNAME-$USER} on Unix platforms,
$USERNAME on native Windows platforms.
*/
-# if !@HAVE_DECL_GETLOGIN@
+# if @REPLACE_GETLOGIN@
+# if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+# define getlogin rpl_getlogin
+# endif
+_GL_FUNCDECL_RPL (getlogin, char *, (void), );
+_GL_CXXALIAS_RPL (getlogin, char *, (void));
+# else
+# if !@HAVE_DECL_GETLOGIN@
_GL_FUNCDECL_SYS (getlogin, char *, (void), );
-# endif
+# endif
_GL_CXXALIAS_SYS (getlogin, char *, (void));
+# endif
+# if __GLIBC__ >= 2
_GL_CXXALIASWARN (getlogin);
+# endif
#elif defined GNULIB_POSIXCHECK
# undef getlogin
# if HAVE_RAW_DECL_GETLOGIN
diff --git a/m4/getlogin.m4 b/m4/getlogin.m4
index e876fad5ea..7f1f07319d 100644
--- a/m4/getlogin.m4
+++ b/m4/getlogin.m4
@@ -1,5 +1,5 @@
# getlogin.m4
-# serial 7
+# serial 8
dnl Copyright (C) 2010-2025 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -16,6 +16,53 @@ AC_DEFUN([gl_FUNC_GETLOGIN]
AC_CHECK_FUNCS_ONCE([getlogin])
if test $ac_cv_func_getlogin = no; then
HAVE_GETLOGIN=0
+ else
+ dnl On musl libc, getlogin returns getenv ("LOGNAME").
+ AC_REQUIRE([AC_CANONICAL_HOST])
+ AC_CACHE_CHECK([whether getlogin works],
+ [gl_cv_func_getlogin_works],
+ [
+ dnl Initial guess, used when cross-compiling.
+changequote(,)dnl
+ case "$host_os" in
+ # Guess no on musl libc.
+ *-musl* | midipix*) gl_cv_func_getlogin_works="guessing no" ;;
+ # Guess yes otherwise.
+ *) gl_cv_func_getlogin_works="guessing yes" ;;
+ esac
+changequote([,])dnl
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#if !HAVE_DECL_GETLOGIN
+extern
+# ifdef __cplusplus
+"C"
+# endif
+char *getlogin (void);
+#endif
+int
+main (void)
+{
+ int result = 0;
+ char *buf;
+
+ putenv ("LOGNAME=ygvfibmslhkmvoetbrcegzwydorcke");
+ buf = getlogin ();
+ if (buf != NULL && strcmp (buf, "ygvfibmslhkmvoetbrcegzwydorcke") == 0)
+ result |= 1;
+ return result;
+}]])],
+ [gl_cv_func_getlogin_works=yes],
+ [gl_cv_func_getlogin_works=no],
+ [:])
+ ])
+ case "$gl_cv_func_getlogin_works" in
+ *yes) ;;
+ *) REPLACE_GETLOGIN=1 ;;
+ esac
fi
])
diff --git a/m4/unistd_h.m4 b/m4/unistd_h.m4
index 2c08d65e0d..6ec16286ef 100644
--- a/m4/unistd_h.m4
+++ b/m4/unistd_h.m4
@@ -1,5 +1,5 @@
# unistd_h.m4
-# serial 96
+# serial 97
dnl Copyright (C) 2006-2025 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -244,6 +244,7 @@ AC_DEFUN([gl_UNISTD_H_DEFAULTS]
REPLACE_GETDOMAINNAME=0; AC_SUBST([REPLACE_GETDOMAINNAME])
REPLACE_GETDTABLESIZE=0; AC_SUBST([REPLACE_GETDTABLESIZE])
REPLACE_GETENTROPY=0; AC_SUBST([REPLACE_GETENTROPY])
+ REPLACE_GETLOGIN=0; AC_SUBST([REPLACE_GETLOGIN])
REPLACE_GETLOGIN_R=0; AC_SUBST([REPLACE_GETLOGIN_R])
REPLACE_GETGROUPS=0; AC_SUBST([REPLACE_GETGROUPS])
REPLACE_GETPAGESIZE=0; AC_SUBST([REPLACE_GETPAGESIZE])
diff --git a/modules/getlogin b/modules/getlogin
index 8725a7031e..7acee58a81 100644
--- a/modules/getlogin
+++ b/modules/getlogin
@@ -7,10 +7,12 @@ m4/getlogin.m4
Depends-on:
unistd-h
+readutmp [test $HAVE_GETLOGIN = 0 || test $REPLACE_GETLOGIN = 1]
configure.ac:
gl_FUNC_GETLOGIN
-gl_CONDITIONAL([GL_COND_OBJ_GETLOGIN], [test $HAVE_GETLOGIN = 0])
+gl_CONDITIONAL([GL_COND_OBJ_GETLOGIN],
+ [test $HAVE_GETLOGIN = 0 || test $REPLACE_GETLOGIN = 1])
gl_UNISTD_MODULE_INDICATOR([getlogin])
AC_REQUIRE([gl_LIB_GETLOGIN])
@@ -26,7 +28,7 @@ Link:
$(GETLOGIN_LIB)
License:
-LGPLv2+
+GPL
Maintainer:
all
diff --git a/modules/unistd-h b/modules/unistd-h
index 1a7376efdb..0fdb6368b3 100644
--- a/modules/unistd-h
+++ b/modules/unistd-h
@@ -201,6 +201,7 @@ unistd.h: unistd.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H
-e 's|@''REPLACE_GETDOMAINNAME''@|$(REPLACE_GETDOMAINNAME)|g' \
-e 's|@''REPLACE_GETDTABLESIZE''@|$(REPLACE_GETDTABLESIZE)|g' \
-e 's|@''REPLACE_GETENTROPY''@|$(REPLACE_GETENTROPY)|g' \
+ -e 's|@''REPLACE_GETLOGIN''@|$(REPLACE_GETLOGIN)|g' \
-e 's|@''REPLACE_GETLOGIN_R''@|$(REPLACE_GETLOGIN_R)|g' \
-e 's|@''REPLACE_GETGROUPS''@|$(REPLACE_GETGROUPS)|g' \
-e 's|@''REPLACE_GETPAGESIZE''@|$(REPLACE_GETPAGESIZE)|g' \
diff --git a/tests/test-getlogin.c b/tests/test-getlogin.c
index 1b980a152d..431844bd71 100644
--- a/tests/test-getlogin.c
+++ b/tests/test-getlogin.c
@@ -41,5 +41,11 @@ main (void)
#endif
test_getlogin_result (buf, err);
+ /* Check that getlogin() does not merely return getenv ("LOGNAME"). */
+ putenv ("LOGNAME=ygvfibmslhkmvoetbrcegzwydorcke");
+ buf = getlogin ();
+ ASSERT (!(buf != NULL
+ && strcmp (buf, "ygvfibmslhkmvoetbrcegzwydorcke") == 0));
+
return test_exit_status;
}
--
2.43.0
>From 0bca572030d26721cb81800ff4264b6f18dc7e40 Mon Sep 17 00:00:00 2001
From: Bruno Haible <br...@clisp.org>
Date: Sun, 9 Mar 2025 10:19:20 +0100
Subject: [PATCH 2/2] getlogin_r: Work around musl bug.
* lib/getlogin_r.c (getlogin_r): Add implementation for Linux.
* m4/getlogin_r.m4 (gl_FUNC_GETLOGIN_R): Test whether getlogin_r has the
musl bug.
* tests/test-getlogin_r.c (main): Add another test.
* doc/posix-functions/getlogin_r.texi: Mention the workaround.
---
ChangeLog | 9 ++++
doc/posix-functions/getlogin_r.texi | 6 +--
lib/getlogin_r.c | 74 +++++++++++++++++++++++++++++
m4/getlogin_r.m4 | 20 +++++---
tests/test-getlogin_r.c | 5 ++
5 files changed, 105 insertions(+), 9 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 6d2ad66c83..d8eb0e8df7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2025-03-09 Bruno Haible <br...@clisp.org>
+
+ getlogin_r: Work around musl bug.
+ * lib/getlogin_r.c (getlogin_r): Add implementation for Linux.
+ * m4/getlogin_r.m4 (gl_FUNC_GETLOGIN_R): Test whether getlogin_r has the
+ musl bug.
+ * tests/test-getlogin_r.c (main): Add another test.
+ * doc/posix-functions/getlogin_r.texi: Mention the workaround.
+
2025-03-09 Bruno Haible <br...@clisp.org>
getlogin: Work around musl bug.
diff --git a/doc/posix-functions/getlogin_r.texi b/doc/posix-functions/getlogin_r.texi
index daafd9eaa0..df145ecfe2 100644
--- a/doc/posix-functions/getlogin_r.texi
+++ b/doc/posix-functions/getlogin_r.texi
@@ -20,6 +20,9 @@
This function returns a truncated result, instead of failing with error code
@code{ERANGE}, when the buffer is not large enough, on some platforms:
macOS 14.
+@item
+This function returns the value of the @env{LOGNAME} environment variable:
+musl libc 1.2.5.
@end itemize
Portability problems not fixed by Gnulib:
@@ -28,9 +31,6 @@
This function has an incompatible declaration on some platforms:
FreeBSD 12.0, MidnightBSD 2.0, Solaris 11.4 (when @code{_POSIX_PTHREAD_SEMANTICS} is not defined).
@item
-This function returns the value of the @env{LOGNAME} environment variable:
-musl libc 1.2.5.
-@item
This function fails even when standard input is a tty on some platforms:
HP-UX 11.11.
@item
diff --git a/lib/getlogin_r.c b/lib/getlogin_r.c
index 6a13e8e405..ade819940e 100644
--- a/lib/getlogin_r.c
+++ b/lib/getlogin_r.c
@@ -39,6 +39,14 @@ extern char *getlogin (void);
# endif
#endif
+#if defined __linux__ || defined __ANDROID__
+# include <fcntl.h>
+# include <pwd.h>
+# include <stdlib.h>
+# include <string.h>
+# include <sys/stat.h>
+#endif
+
/* See unistd.in.h for documentation. */
int
getlogin_r (char *name, size_t size)
@@ -64,6 +72,72 @@ getlogin_r (char *name, size_t size)
return ENOENT;
}
return 0;
+#elif defined __linux__ || defined __ANDROID__
+ /* Linux. */
+ {
+ /* Read the login uid from the /proc file system. */
+ int fd = open ("/proc/self/loginuid", O_RDONLY);
+ if (fd >= 0)
+ {
+ char buf[20 + 1];
+ int n = read (fd, buf, sizeof (buf) - 1);
+ if (n > 0)
+ {
+ buf[n] = '\0';
+ char *endptr;
+ unsigned long uid = strtoul (buf, &endptr, 10);
+ if (endptr == buf + n && uid != (uid_t) -1)
+ {
+ /* Convert the uid to a user name. */
+ struct passwd pbuf1;
+ char pbuf2[1024];
+ struct passwd *p;
+ if (getpwuid_r (uid, &pbuf1, pbuf2, sizeof (pbuf2), &p) == 0)
+ {
+ if (strlen (p->pw_name) < size)
+ {
+ strcpy (name, p->pw_name);
+ close (fd);
+ return 0;
+ }
+ return ERANGE;
+ }
+ }
+ }
+ close (fd);
+ }
+ }
+ {
+ /* Find the tty connected to the current process. */
+ char tty[1024];
+ if (ttyname_r (STDIN_FILENO, tty, sizeof (tty)) == 0)
+ {
+ /* We cannot use read_utmp here, since it is not multithread-safe. */
+ /* Fallback for systems which don't maintain an utmp database
+ or for ttys that are not recorded in that the utmp database:
+ Look at the owner of that tty. */
+ struct stat statbuf;
+ if (stat (tty, &statbuf) >= 0)
+ {
+ uid_t uid = statbuf.st_uid;
+ /* Convert the uid to a user name. */
+ struct passwd pbuf1;
+ char pbuf2[1024];
+ struct passwd *p;
+ if (getpwuid_r (uid, &pbuf1, pbuf2, sizeof (pbuf2), &p) == 0)
+ {
+ if (strlen (p->pw_name) < size)
+ {
+ strcpy (name, p->pw_name);
+ return 0;
+ }
+ return ERANGE;
+ }
+ }
+ }
+ }
+ /* ENOENT is a reasonable errno value if getlogin returns NULL. */
+ return ENOENT;
#elif HAVE_GETLOGIN_R
/* Platform with a getlogin_r() function. */
int ret = getlogin_r (name, size);
diff --git a/m4/getlogin_r.m4 b/m4/getlogin_r.m4
index 26664e1fda..5ac8a89ff8 100644
--- a/m4/getlogin_r.m4
+++ b/m4/getlogin_r.m4
@@ -1,5 +1,5 @@
# getlogin_r.m4
-# serial 15
+# serial 16
dnl Copyright (C) 2005-2007, 2009-2025 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -35,22 +35,26 @@ AC_DEFUN([gl_FUNC_GETLOGIN_R]
HAVE_GETLOGIN_R=1
dnl On Mac OS X 10.13 and OSF/1 5.1, getlogin_r returns a truncated result
dnl if the buffer is not large enough.
+ dnl On musl libc, getlogin_r returns getenv ("LOGNAME").
AC_REQUIRE([AC_CANONICAL_HOST])
- AC_CACHE_CHECK([whether getlogin_r works with small buffers],
+ AC_CACHE_CHECK([whether getlogin_r works],
[gl_cv_func_getlogin_r_works],
[
dnl Initial guess, used when cross-compiling.
changequote(,)dnl
case "$host_os" in
- # Guess no on Mac OS X, OSF/1.
- darwin* | osf*) gl_cv_func_getlogin_r_works="guessing no" ;;
- # Guess yes otherwise.
- *) gl_cv_func_getlogin_r_works="guessing yes" ;;
+ # Guess no on Mac OS X, OSF/1.
+ darwin* | osf*) gl_cv_func_getlogin_r_works="guessing no" ;;
+ # Guess no on musl libc.
+ *-musl* | midipix*) gl_cv_func_getlogin_r_works="guessing no" ;;
+ # Guess yes otherwise.
+ *) gl_cv_func_getlogin_r_works="guessing yes" ;;
esac
changequote([,])dnl
AC_RUN_IFELSE(
[AC_LANG_SOURCE([[
#include <stddef.h>
+#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#if !HAVE_DECL_GETLOGIN_R
@@ -76,6 +80,10 @@ AC_DEFUN([gl_FUNC_GETLOGIN_R]
if (getlogin_r (buf, n) == 0)
result |= 4;
}
+ putenv ("LOGNAME=ygvfibmslhkmvoetbrcegzwydorcke");
+ if (getlogin_r (buf, 100) == 0
+ && strcmp (buf, "ygvfibmslhkmvoetbrcegzwydorcke") == 0)
+ result |= 8;
return result;
}]])],
[gl_cv_func_getlogin_r_works=yes],
diff --git a/tests/test-getlogin_r.c b/tests/test-getlogin_r.c
index 4deddfbb01..3674195e55 100644
--- a/tests/test-getlogin_r.c
+++ b/tests/test-getlogin_r.c
@@ -68,5 +68,10 @@ main (void)
ASSERT (strcmp (hugebuf, buf) == 0);
}
+ /* Check that getlogin_r() does not merely return getenv ("LOGNAME"). */
+ putenv ("LOGNAME=ygvfibmslhkmvoetbrcegzwydorcke");
+ err = getlogin_r (buf, sizeof buf);
+ ASSERT (!(err == 0 && strcmp (buf, "ygvfibmslhkmvoetbrcegzwydorcke") == 0));
+
return test_exit_status;
}
--
2.43.0
