t/660-stamp: don't run at the same time as other tests in redo -j.

flush-cache can cause files affected by redo-stamp to get rebuilt
unnecessarily, which the test is specifically trying to validate.
Since other tests run flush-cache at random times when using -j, this
would cause random test failures.

t/s60-stamp/.gitignore

@@ -0,0 +1,12 @@
+/*.log
+/usestamp
+/stampy
+/inp
+/bob
+/usestamp2
+/a
+/b
+/ab
+/doing_ab
+/abc
+/doing_abc

t/s60-stamp/a.do

@@ -0,0 +1,3 @@
+redo-always
+echo a | redo-stamp
+echo a > $3

t/s60-stamp/ab.do

@@ -0,0 +1,4 @@
+redo-ifchange a b
+echo "doing ab" >&2
+echo ab >$3
+touch doing_ab

t/s60-stamp/abc.do

@@ -0,0 +1,4 @@
+redo-ifchange ab c
+echo "doing abc" >&2
+echo abc >$3
+touch doing_abc

t/s60-stamp/all.do

@@ -0,0 +1 @@
+redo stamptest

t/s60-stamp/b.do

@@ -0,0 +1,3 @@
+redo-always
+echo b | redo-stamp
+echo b > $3

t/s60-stamp/bob.do

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

t/s60-stamp/clean.do

@@ -0,0 +1 @@
+rm -f *.log usestamp usestamp2 stampy inp bob *~ .*~ a b ab abc doing_ab

t/s60-stamp/stamptest.do

@@ -0,0 +1,85 @@
+rm -f bob stampy usestamp usestamp2 stampy.log usestamp.log usestamp2.log
+echo one >inp
+
+../flush-cache
+redo stampy
+[ "$(wc -l <stampy.log)" -eq 1 ] || exit 11
+
+# stampy already exists, so we won't generate it a second time, even though
+# usestamp depends on it.
+../flush-cache
+redo-ifchange usestamp
+[ "$(wc -l <stampy.log)" -eq 1 ] || exit 21
+[ "$(wc -l <usestamp.log)" -eq 1 ] || exit 12
+
+../flush-cache
+redo stampy
+. ../skip-if-minimal-do.sh
+[ "$(wc -l <stampy.log)" -eq 2 ] || exit 31
+[ "$(wc -l <usestamp.log)" -eq 1 ] || exit 32
+
+# same as above: stampy is already up-to-date, so it won't be redone.
+../flush-cache
+redo-ifchange usestamp
+[ "$(wc -l <stampy.log)" -eq 2 ] || exit 41
+[ "$(wc -l <usestamp.log)" -eq 1 ] || exit 42
+
+# stampy depends on bob, so we'll have to rebuild stampy automatically.  But
+# stampy's checksum will still be identical, so usestamp shouldn't rebuild.
+../flush-cache
+redo bob
+../flush-cache
+redo-ifchange usestamp
+[ "$(wc -l <stampy.log)" -eq 3 ] || exit 43
+[ "$(wc -l <usestamp.log)" -eq 1 ] || exit 44
+
+# Make sure the previous step correctly marked stampy and usestamp as
+# up-to-date even though *neither* of them is newer than bob.
+../flush-cache
+redo-ifchange usestamp
+[ "$(wc -l <stampy.log)" -eq 3 ] || exit 45
+[ "$(wc -l <usestamp.log)" -eq 1 ] || exit 46
+
+# now we're changing the contents of stampy.  Thus usestamp will need to
+# be rebuilt, but not yet...
+echo two >inp
+../flush-cache
+redo stampy
+[ "$(wc -l <stampy.log)" -eq 4 ] || exit 51
+[ "$(wc -l <usestamp.log)" -eq 1 ] || exit 52
+
+# let's see about usestamp.  It needs to be rebuilt because stampy has changed,
+# but since stampy is *already* changed, stampy itself shouldn't be re-rebuilt.
+../flush-cache
+redo-ifchange usestamp usestamp2
+[ "$(wc -l <stampy.log)" -eq 4 ] || exit 61
+[ "$(wc -l <usestamp.log)" -eq 2 ] || exit 62
+[ "$(wc -l <usestamp2.log)" -eq 1 ] || exit 62
+
+# when we delete the file and it gets regenerated identically, it's as good as
+# never having been deleted.  So usestamp won't need to change.
+../flush-cache
+rm -f stampy
+redo-ifchange usestamp usestamp2
+[ "$(wc -l <stampy.log)" -eq 5 ] || exit 71
+[ "$(wc -l <usestamp.log)" -eq 2 ] || exit 72
+[ "$(wc -l <usestamp2.log)" -eq 1 ] || exit 73
+
+# this simple test used to cause a deadlock.
+../flush-cache
+rm -f stampy
+redo-ifchange stampy
+[ "$(wc -l <stampy.log)" -eq 6 ] || exit 74
+
+# check that a target that depends on two stamped targets (that are marked as
+# always built) won't be redone if neither stamped targets changes
+../flush-cache
+redo-ifchange abc
+rm -f doing_ab doing_abc
+redo-ifchange abc
+[ ! -f doing_ab ] || exit 92
+[ ! -f doing_abc ] || exit 93
+../flush-cache
+redo-ifchange abc
+[ ! -f doing_ab ] || exit 94
+[ ! -f doing_abc ] || exit 95

t/s60-stamp/stampy.do

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+echo $$ >>stampy.log
+redo-ifchange inp bob
+cat inp
+cd ..
+redo-stamp <s60-stamp/inp

t/s60-stamp/usestamp.do

@@ -0,0 +1,3 @@
+redo-ifchange stampy
+echo $$ >>usestamp.log
+cat stampy

t/s60-stamp/usestamp2.do

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+redo-ifchange stampy
+echo 2 $$ >>usestamp2.log
+cat stampy