--- gforth/configure.in	2008/08/13 19:15:43	1.238
+++ gforth/configure.in	2008/08/19 18:57:19	1.242
@@ -623,11 +623,12 @@ AC_MSG_RESULT($M4)
 # Find installed Gforth
 AC_MSG_CHECKING([for gforth])
 GFORTH="`cd / && which gforth 2>/dev/null`"
+(cd / && $GFORTH -e bye >/dev/null 2>/dev/null) || GFORTH=""
 if test -z "$GFORTH"; then
   PREFORTH='echo "You need to configure with a gforth in \$PATH to build this part" && false'
   kernel_anti_dependence=''
 else
-  PREFORTH="$GFORTH -i `cd / && gforth --debug -e bye 2>&1 |grep "Opened image file: "|sed 's/Opened image file: //'`" ;
+  PREFORTH="$GFORTH -i `cd / && $GFORTH --debug -e bye 2>&1 |grep "Opened image file: "|sed 's/Opened image file: //'`" ;
   kernel_anti_dependence='$(kernel_fi)'
 fi
 AC_SUBST(PREFORTH)
@@ -816,7 +817,7 @@ if test -z "$FFI_H_NAME"; then
 fi
 AC_SUBST(FFI_H_NAME)
 AC_CHECK_LIB(ffi,ffi_call)
-if test $ac_cv_lib_ffi_ffi_call = yes
+if test -n "$FFI_H_NAME" -a $ac_cv_lib_ffi_ffi_call = yes
 then
   LIBFFIFLAG="true"
   LIBCC_BUILD_SRC="$LIBCC_BUILD_SRC libffi.fs"
@@ -855,7 +856,7 @@ AC_CHECK_FUNCS(expm1 log1p)
 AC_REPLACE_FUNCS(rint ecvt)
 dnl No check for select, because our replacement is no good under
 dnl anything but DOS
-AC_CHECK_HEADERS(sys/mman.h fnmatch.h)
+AC_CHECK_HEADERS(sys/mman.h fnmatch.h alloca.h)
 AC_FUNC_FNMATCH
 test $ac_cv_func_fnmatch_works = yes || AC_LIBOBJ(fnmatch)
 AC_CHECK_FUNCS(mmap sysconf getpagesize)