- introduce variable _BB_CONFIG_DEP to the new test harness.

This is used to see if given tests should be run (are available) or not.
  Print "UNTESTED: descr" if the applet or feature is not available.
- add _BB_CONFIG_DEP to existing new.tests
- move old grep test to new test infrastructure and add a few more test for
  grep.

testsuite/testing.sh

@@ -28,9 +28,19 @@ fi
 
 export FAILCOUNT=0
 
+# Helper functions
+
+config_is_set ()
+{
+  local uc_what=$(echo ${1?} | tr a-z A-Z)
+  grep -q "^[ 	]*CONFIG_${uc_what}" ${bindir:-..}/.config || \
+    grep -q "^[ 	]*BB_CONFIG_${uc_what}" ${bindir:-..}/.config
+  return $?
+}
+
 # The testing function
 
-function testing()
+testing()
 {
   if [ $# -ne 5 ]
   then
@@ -38,6 +48,15 @@ function testing()
     exit
   fi
 
+  if [ ${force_tests:-0} -ne 1 -a -n "$_BB_CONFIG_DEP" ]
+  then
+    if ! config_is_set "$_BB_CONFIG_DEP"
+    then
+      echo "UNTESTED: $1"
+      return 0
+    fi
+  fi
+
   f=$FAILCOUNT
   echo -ne "$3" > expected
   echo -ne "$4" > input