jwack: _cheatfds error when run from toplevel make -j.

Also added a new unit test to confirm that 'make' behaviour works as
expected, with and without parallelism.

jwack.py

@@ -235,6 +235,9 @@ def setup(maxjobs):
         if a <= 0 or b <= 0:
             raise ValueError('invalid REDO_CHEATFDS: %r' % cheats)
         _cheatfds = (a, b)
+    else:
+        _cheatfds = _make_pipe(102)
+        os.putenv('REDO_CHEATFDS', '%d,%d' % (_cheatfds[0], _cheatfds[1]))
 
     if not _tokenfds:
         # need to start a new server
@@ -247,8 +250,6 @@ def setup(maxjobs):
                   (os.getenv('MAKEFLAGS', ''),
                    _tokenfds[0], _tokenfds[1],
                    _tokenfds[0], _tokenfds[1]))
-        _cheatfds = _make_pipe(102)
-        os.putenv('REDO_CHEATFDS', '%d,%d' % (_cheatfds[0], _cheatfds[1]))
 
 
 def _wait(want_token, max_delay):

minimal/do

@@ -54,12 +54,13 @@ if [ -z "$DO_BUILT" ]; then
 	export _do_opt_verbose=
 	export _do_opt_clean=
 fi
-while getopts 'dxvch?' _opt; do
+while getopts 'dxvcj:h?' _opt; do
 	case $_opt in
 		d) _do_opt_debug=1 ;;
 		x) _do_opt_exec=x ;;
 		v) _do_opt_verbose=v ;;
 		c) _do_opt_clean=1 ;;
+		j) ;;  # silently ignore, for compat with real redo
 		\?|h|*) printf "%s" "$USAGE" >&2
 		   exit 99
 		   ;;

t/203-make/.gitignore

@@ -0,0 +1,2 @@
+*.out
+whichmake

t/203-make/Makefile

@@ -0,0 +1,8 @@
+default:
+
+x:
+	+redo x1.out x2.out
+
+y:
+	+redo x
+	+redo y1.out y2.out

t/203-make/all.do

@@ -0,0 +1,20 @@
+exec >&2
+redo-ifchange whichmake
+
+run() {
+    rm -f *.out
+    ./whichmake y
+
+    rm -f *.out
+    ./whichmake -j10 y
+
+    rm -f *.out
+    redo y
+
+    rm -f *.out
+    redo -j10 y
+}
+
+run
+. ./wipe-redo.sh
+run

t/203-make/clean.do

@@ -0,0 +1 @@
+rm -f *~ .*~ *.out whichmake

t/203-make/default.out.do

@@ -0,0 +1 @@
+echo $1 >$3

t/203-make/whichmake.do

@@ -0,0 +1,16 @@
+if type gmake >/dev/null 2>/dev/null; then
+	make=gmake
+elif type make >/dev/null 2>/dev/null; then
+	make=make
+else
+	# No make installed?  That's okay, this test
+	# isn't *that* important.
+	make=:
+fi
+
+cat >$3 <<-EOF
+	#!/bin/sh
+	$make "\$@"
+EOF
+chmod a+x $3
+

t/203-make/wipe-redo.sh

@@ -0,0 +1,13 @@
+vars=$(
+	env | {
+		IFS="="
+		while read key value; do
+			if [ "$key" != "${key#REDO}" ] ||
+			   [ "$key" != "${key#MAKE}" ]; then
+				echo "$key"
+			fi
+		done
+	}
+)
+echo "Wiping vars:" $vars >&2
+unset $vars

t/203-make/x.do

@@ -0,0 +1 @@
+./whichmake x >&2

t/203-make/y.do

@@ -0,0 +1 @@
+./whichmake y >&2