Use the SONAME-versioned liblua, if it exists. (James Vega)
diff --git a/src/configure.in b/src/configure.in
index f472210..38fdea5 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -452,7 +452,7 @@
       if test "X$vi_cv_path_lua" != "X"; then
         dnl -- find Lua version
         AC_CACHE_CHECK(Lua version, vi_cv_version_lua,
-        [ vi_cv_version_lua=`${vi_cv_path_lua} -e "print(_VERSION:sub(5,7))"` ])
+        [ vi_cv_version_lua=`${vi_cv_path_lua} -e "print(_VERSION)" | sed 's/.* //'` ])
         AC_MSG_CHECKING(if lua.h can be found in $vi_cv_path_lua_pfx/include/lua$vi_cv_version_lua)
         if test -f $vi_cv_path_lua_pfx/include/lua$vi_cv_version_lua/lua.h; then
           AC_MSG_RESULT(yes)
@@ -478,9 +478,17 @@
     LUA_PRO="if_lua.pro"
     AC_DEFINE(FEAT_LUA)
     if test "$enable_luainterp" = "dynamic"; then
+      dnl Determine the SONAME for the current version, but fallback to
+      dnl liblua${vi_cv_version_lua}.so if no SONAME-versioned file is found.
+      for i in 0 1 2 3 4 5 6 7 8 9; do
+	if test -f "${vi_cv_path_lua_pfx}/lib/liblua${vi_cv_version_lua}.so.$i"; then
+	  LUA_SONAME=".$i"
+	  break
+	fi
+      done
       AC_DEFINE(DYNAMIC_LUA)
       LUA_LIBS=""
-      LUA_CFLAGS="-DDYNAMIC_LUA_DLL=\\\"liblua${vi_cv_version_lua}.so\\\" $LUA_CFLAGS"
+      LUA_CFLAGS="-DDYNAMIC_LUA_DLL=\\\"liblua${vi_cv_version_lua}.so$LUA_SONAME\\\" $LUA_CFLAGS"
     fi
   fi
   AC_SUBST(LUA_SRC)