vim: fix gettext check

configure: use minimal LIBS during gettext check

In some configurations, vim fails to link correctly with messages such as:

edit.c:(.text+0x1614): undefined reference to `libintl_gettext'

In particular, this has been seen by the buildroot autobuilds (see [1]) but

has also been reported at [2] and [3].

In the bad case, the configure script says:

checking for NLS... gettext() works

In the good case, it says:

checking for NLS... gettext() works with -lintl

In the bad case, the system has libelf, vim detects that and takes it along

in $LIBS. Libelf needs libintl on this system, and so linking the test

program with -lelf will automatically take -lintl too. This causes configure

to think gettext() does not need libintl, while in reality it does.

In the good case, libelf is not present and thus not used. The first

configure test for gettext fails, and then configure retries with -lintl

(which succeeds).

Until now, there isn't really a problem. In both cases, you could link

correctly. In the 'bad' case, libintl is implicitly taken through libelf, in

the second case it is explicitly taken.

The real problem occurs because configure also tests whether the linker

supports --as-needed and uses it when possible, instead of the link.sh

script. However, --as-needed seems to cause libintl NOT to be taken in the

bad case, causing the undefined references to libintl_gettext.

This patch changes the configure script so that the gettext check does not

use additional libraries such as libelf. The test program is linked either

with nothing, or with libintl alone. This will cause libintl to

be added explicitly to LIBS, when needed.

[1] http://autobuild.buildroot.net/results/21b5a910e6a27fa1cb12d0002ffed7e6ed9d6c83/

[2] http://lists.freebsd.org/pipermail/freebsd-ports-bugs/2012-November/243930.html

[3] http://lists.freebsd.org/pipermail/freebsd-ports-bugs/2012-May/234184.html

Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>

Upstream-status: accepted (http://article.gmane.org/gmane.editors.vim.devel/43528)

---

 src/auto/configure |  11 ++++++-----

 src/configure.in   |  13 +++++++++----

 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/src/auto/configure b/src/auto/configure

--- a/src/auto/configure

+++ b/src/auto/configure

@@ -12271,6 +12271,8 @@ fi

   if test -f po/Makefile; then

     have_gettext="no"

     if test -n "$MSGFMT"; then

+      olibs=$LIBS

+      LIBS=""

       cat confdefs.h - <<_ACEOF >conftest.$ac_ext

 /* end confdefs.h.  */

 #include <libintl.h>

@@ -12284,10 +12286,9 @@ gettext("Test");

 _ACEOF

 if ac_fn_c_try_link "$LINENO"; then :

   { $as_echo "$as_me:${as_lineno-$LINENO}: result: gettext() works" >&5

-$as_echo "gettext() works" >&6; }; have_gettext="yes"

-else

-  olibs=$LIBS

-	  LIBS="$LIBS -lintl"

+$as_echo "gettext() works" >&6; }; have_gettext="yes"; LIBS=$olibs;

+else

+	  LIBS="-lintl"

 	  cat confdefs.h - <<_ACEOF >conftest.$ac_ext

 /* end confdefs.h.  */

 #include <libintl.h>

@@ -12301,7 +12302,7 @@ gettext("Test");

 _ACEOF

 if ac_fn_c_try_link "$LINENO"; then :

   { $as_echo "$as_me:${as_lineno-$LINENO}: result: gettext() works with -lintl" >&5

-$as_echo "gettext() works with -lintl" >&6; }; have_gettext="yes"

+$as_echo "gettext() works with -lintl" >&6; }; have_gettext="yes"; LIBS="$olibs -lintl";

 else

   { $as_echo "$as_me:${as_lineno-$LINENO}: result: gettext() doesn't work" >&5

 $as_echo "gettext() doesn't work" >&6; };

diff --git a/src/configure.in b/src/configure.in

--- a/src/configure.in

+++ b/src/configure.in

@@ -3484,6 +3484,9 @@ if test "$MANDEF" = "man -s"; then

 fi

 dnl Check if gettext() is working and if it needs -lintl

+dnl We take care to base this on an empty LIBS: on some systems libelf would be

+dnl in LIBS and implicitly take along libintl. The final LIBS would then not

+dnl contain libintl, and the link step would fail due to -Wl,--as-needed.

 AC_MSG_CHECKING(--disable-nls argument)

 AC_ARG_ENABLE(nls,

 	[  --disable-nls           Don't support NLS (gettext()).], ,

@@ -3502,16 +3505,18 @@ if test "$enable_nls" = "yes"; then

   if test -f po/Makefile; then

     have_gettext="no"

     if test -n "$MSGFMT"; then

+      olibs=$LIBS

+      LIBS=""

       AC_TRY_LINK(

 	[#include <libintl.h>],

 	[gettext("Test");],

-	AC_MSG_RESULT([gettext() works]); have_gettext="yes",

-	  olibs=$LIBS

-	  LIBS="$LIBS -lintl"

+	AC_MSG_RESULT([gettext() works]); have_gettext="yes"; LIBS=$olibs,

+	  LIBS="-lintl"

 	  AC_TRY_LINK(

 	      [#include <libintl.h>],

 	      [gettext("Test");],

-	      AC_MSG_RESULT([gettext() works with -lintl]); have_gettext="yes",

+	      AC_MSG_RESULT([gettext() works with -lintl]); have_gettext="yes";

+	      LIBS="$olibs -lintl",

 	      AC_MSG_RESULT([gettext() doesn't work]);

 	      LIBS=$olibs))

     else