Do not require libm when searching for system boost

Doing so breaks building under Haiku, which does not have libm.

See ticket #7568 for details.

diff --git a/config/lyxinclude.m4 b/config/lyxinclude.m4
index 03746027d7d9ae4f8ea5a33c7eb0a99388c79f73..dc744972e760b57be5faf2f14b500e74a8b06bbb 100644 (file)
--- a/config/lyxinclude.m4
+++ b/config/lyxinclude.m4
@@ -388,7 +388,7 @@ AC_DEFUN([LYX_USE_INCLUDED_BOOST],[
            save_LIBS=$LIBS
 
            AC_MSG_CHECKING([for multithreaded boost libraries])
-           LIBS="$save_LIBS -lboost_signals-mt -lm $LIBTHREAD"
+           LIBS="$save_LIBS -lboost_signals-mt $LIBTHREAD"
            AC_LINK_IFELSE(
                [AC_LANG_PROGRAM([#include <boost/signal.hpp>],
                        [boost::signal<void ()> s;])],
@@ -396,7 +396,7 @@ AC_DEFUN([LYX_USE_INCLUDED_BOOST],[
                 BOOST_MT="-mt"],
                [AC_MSG_RESULT([no])
                 AC_MSG_CHECKING([for plain boost libraries])
-                LIBS="$save_LIBS -lboost_signals -lm"
+                LIBS="$save_LIBS -lboost_signals"
                 AC_LINK_IFELSE(
                     [AC_LANG_PROGRAM([#include <boost/signal.hpp>],
                             [boost::signal<void ()> s;])],
@@ -459,9 +459,9 @@ AC_DEFUN([LYX_USE_INCLUDED_MYTHES],[
                if test x$ac_cv_header_mythes_h != xyes; then
                        AC_CHECK_HEADER(mythes/mythes.hxx,[ac_cv_header_mythes_h=yes lyx_cv_mythes_h_location="<mythes/mythes.hxx>"])
                fi
-               AC_CHECK_LIB(mythes, main, [MYTHES_LIBS="-lmythes" lyx_mythes=yes], [lyx_mythes=no], [-lm])
+               AC_CHECK_LIB(mythes, main, [MYTHES_LIBS="-lmythes" lyx_mythes=yes], [lyx_mythes=no])
                if test x$lyx_mythes != xyes; then
-                       AC_CHECK_LIB(mythes-1.2, main, [MYTHES_LIBS="-lmythes-1.2" lyx_mythes=yes], [lyx_mythes=no], [-lm])
+                       AC_CHECK_LIB(mythes-1.2, main, [MYTHES_LIBS="-lmythes-1.2" lyx_mythes=yes], [lyx_mythes=no])
                fi
                AC_LANG_POP(C++)
                if test x$lyx_mythes != xyes -o x$ac_cv_header_mythes_h != xyes; then