buildroot

fix static link with readline

​

When readline is static library, we need to link against ncurses

because readline needs ncurses. It is because, dependent library's

symbols are not resolved when static library is built. Those symbols

are resolved program tries to link with static library.

​

We can't pass linker flags for ncurses by setting LIBS environment

variable via <PKG>_CONF_ENV because it looks like build system is not

taking that into account and even though it would have been, order of

linking is important.

​

We can't also pass linker flags for ncurses via --with-readline-libs

conf options because it causes lftp_LIB_READLINE macro to take readline

headers from host machine if available. To use --with-readline-libs

we need to set --with-readline=yes and --with-readline-inc to include

dir. But when --with-readline=yes, readline_prefix is computed based

on if headers can be found in /usr/local or /usr. If readline is

installed on host machine, then configure fails since we are using

headers for host machine. If headers are not found in /usr/local or /usr

then only path specified --with-readline-inc is taken into account.

So specifying linker flags for ncurses via --with-readline-libs will

not work in all cases.

​

So it looks like, updating linker flags directly is only option to fix

static link issue against readline.

​

Signed-off-by: Rahul Bedarkar <rahul.bedarkar@imgtec.com>

​

--- lftp-4.7.3/m4/lftp_lib_readline.m4.old  2016-08-08 19:49:12.217596470 +0530

+++ lftp-4.7.3/m4/lftp_lib_readline.m4  2016-08-08 19:49:46.265596398 +0530

@@ -108,7 +108,7 @@ AC_DEFUN([lftp_LIB_READLINE],

        readline_include_dir="$readline_include_dir/readline"

    fi

         readline_ld_flags="-L$readline_prefix/lib"

-        readline_lib_flags="-lreadline"

+        readline_lib_flags="-lreadline -lncurses"

         run_readline_test="yes"

     elif test "$readline_requested" = "yes"; then

         if test -n "$readline_include_dir" -a -n "$readline_lib_flags"; then