Add a redo-ifcreate test.

Turns out we weren't testing this one at all, which is a shame, because it
totally didn't work.

t/.gitignore

@@ -18,3 +18,6 @@ test2.args
 /deltest2
 /always1
 /always1.log
+/ifcreate[12].log
+/ifcreate[12].dep
+/ifcreate[12]

t/clean.do

@@ -1,5 +1,5 @@
 redo example/clean curse/clean deps/clean "space dir/clean" stamp/clean
 rm -f c c.c c.c.c c.c.c.b c.c.c.b.b d mode1 makedir.log chdir1 deltest2 \
 	hello [by]ellow *.o *~ .*~ *.log CC LD passfail silence silence.do \
-	touch1 touch1.do always1
+	touch1 touch1.do always1 ifcreate[12].dep ifcreate[12]
 rm -rf makedir

t/ifcreate-test.do

@@ -0,0 +1,21 @@
+rm -f exists ifcreate[12] ifcreate[12].log ifcreate[12].dep
+. ./skip-if-minimal-do.sh
+touch exists
+redo-ifcreate exists 2>/dev/null && exit 91
+rm exists
+redo-ifcreate exists || exit 92
+
+for d in 1 2; do
+	redo ifcreate$d
+	[ "$(wc -l <ifcreate$d.log)" -eq 1 ] || exit ${d}1
+	redo-ifchange ifcreate$d
+	[ "$(wc -l <ifcreate$d.log)" -eq 1 ] || exit ${d}2
+	./flush-cache.sh
+	touch ifcreate$d.dep
+	redo-ifchange ifcreate$d
+	[ "$(wc -l <ifcreate$d.log)" -eq 2 ] || exit ${d}3
+	./flush-cache.sh
+	rm ifcreate$d.dep
+	redo-ifchange ifcreate$d
+	[ "$(wc -l <ifcreate$d.log)" -eq 3 ] || exit ${d}4
+done

t/ifcreate1.do

@@ -0,0 +1,6 @@
+if [ -e ifcreate1.dep ]; then
+	redo-ifchange ifcreate1.dep
+else
+	redo-ifcreate ifcreate1.dep
+fi
+echo $$ >>ifcreate1.log

t/ifcreate2.do

@@ -0,0 +1,7 @@
+cd ..
+if [ -e t/ifcreate2.dep ]; then
+	redo-ifchange t/ifcreate2.dep
+else
+	redo-ifcreate t/ifcreate2.dep
+fi
+echo $$ >>t/ifcreate2.log

t/test.do

@@ -2,4 +2,4 @@ redo-ifchange all
 ./hello >&2
 redo deltest deltest2 test.args test2.args passfailtest chdirtest \
 	curse/test deps/test "space dir/test" modetest makedir2 \
-	silencetest touchtest stamp/test alwaystest
+	silencetest touchtest stamp/test alwaystest ifcreate-test