Undo previous change.

(sig): New var.  Use it insted of "trap '' CHLD".
Append $EXEEXT to executable name.

tests/install/trap

@@ -7,12 +7,6 @@ if test "$VERBOSE" = yes; then
   ginstall --version
 fi
 
-(trap '' CHLD) || {
-  echo >&2 "$0: the shell command \"trap '' CHLD\" does not work," \
-    "so can't run this test"
-  exit 77
-}
-
 pwd=`pwd`
 t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$
 trap 'status=$?; cd $pwd; chmod -R u+rwx $t0; rm -rf $t0 && exit $status' 0
@@ -29,8 +23,10 @@ fi
 
 fail=0
 
+# ash doesn't support "trap '' CHLD"; it knows only signal numbers.
+sig=`$pwd/../../src/kill -l CHLD 2>/dev/null` && trap '' $sig
+
 # Before 2004-04-21, install would infloop, in the `while (wait...' loop:
-trap '' CHLD
-ginstall -s $pwd/../../src/ginstall .
+ginstall -s $pwd/../../src/ginstall$EXEEXT .
 
 (exit $fail); exit $fail