From 712261c89b18c87595db61f377bfd1075160a6e0 Mon Sep 17 00:00:00 2001
From: Martijn Dekker <martijn@inlv.org>
Date: Mon, 8 Jun 2020 23:02:26 +0200
Subject: [PATCH] shtests: More speedups; also fix xtrace (re: 734e5953)

This reduces a bunch more unnecessarily long sleeps to give
asynchronous processes time to run, etc. (No, we don't need to be
compatible anymore with your cool 1985 Intel 80386DX 16 MHz
battlestation...) Running the test suite is almost tolerable now,
making me much more likely to actually run the regression test
suite and catch my own regressions.

In addition, there are various fixes to make the test suite
compatible with 'set -x' ('set -o xtrace') so that you can now
actually *use* the documented 'bin/shtests -x' option. Recommend
combining with '-p' to avoid tracing everything three times.

I've also added a really useful $PS4 trace prompt to shtests that
traces pretty much everything there is to trace. (It does use
expansions that modify ${.sh.match}, which affected several tests,
particularly in tests/substring.sh; for those we need to set a
temporary simpler $PS4.)

(cherry picked from commit c3a5d47cfe880b526cabb5370ddaced0e8626acd)
---
 src/cmd/ksh93/tests/basic.sh     | 56 ++++++++++++++++++--------------
 src/cmd/ksh93/tests/bracket.sh   |  6 ++--
 src/cmd/ksh93/tests/builtins.sh  |  2 +-
 src/cmd/ksh93/tests/coprocess.sh | 36 ++++++++++----------
 src/cmd/ksh93/tests/functions.sh |  7 ++++
 src/cmd/ksh93/tests/io.sh        | 39 ++++++++++++----------
 src/cmd/ksh93/tests/locale.sh    |  6 ++--
 src/cmd/ksh93/tests/options.sh   | 12 +++----
 src/cmd/ksh93/tests/path.sh      |  2 +-
 src/cmd/ksh93/tests/shtests      |  2 +-
 src/cmd/ksh93/tests/sigchld.sh   | 24 +++++++-------
 src/cmd/ksh93/tests/signal.sh    |  6 ++--
 src/cmd/ksh93/tests/subshell.sh  | 47 ++++++++++++++-------------
 src/cmd/ksh93/tests/substring.sh | 41 ++++++++++++++++++++---
 src/cmd/ksh93/tests/variables.sh | 12 ++++---
 15 files changed, 178 insertions(+), 120 deletions(-)

diff --git a/src/cmd/ksh93/tests/basic.sh b/src/cmd/ksh93/tests/basic.sh
index 33b8d64f5..b73ec9474 100755
--- a/src/cmd/ksh93/tests/basic.sh
+++ b/src/cmd/ksh93/tests/basic.sh
@@ -38,6 +38,13 @@ tmp=$(
 trap 'cd / && rm -rf "$tmp"' EXIT
 bincat=$(whence -p cat)
 binecho=$(whence -p echo)
+# make an external 'sleep' command that supports fractional seconds
+binsleep=$tmp/.sleep.sh  # hide to exclude from simple wildcard expansion
+cat >"$binsleep" <<EOF
+#!$SHELL
+sleep "\$@"
+EOF
+chmod +x "$binsleep"
 
 # test basic file operations like redirection, pipes, file expansion
 set -- \
@@ -146,7 +153,7 @@ cd ../../tmp || err_exit "cd ../../tmp failed"
 if	[[ $PWD != /tmp ]]
 then	err_exit 'cd ../../tmp is not /tmp'
 fi
-( sleep 2; cat <<!
+( sleep .2; cat <<!
 foobar
 !
 ) | cat > $tmp/foobar &
@@ -294,7 +301,7 @@ if	[[ $(for i in foo bar
 then	err_exit 'for loop subshell optimizer bug'
 fi
 unset a1
-optbug()
+function optbug
 {
 	set -A a1  foo bar bam
 	integer i
@@ -307,15 +314,15 @@ optbug()
 	done
 	return 1
 }
-optbug ||  err_exit 'array size optimzation bug'
+optbug ||  err_exit 'array size optimization bug'
 wait # not running --pipefail which would interfere with subsequent tests
 : $(jobs -p) # required to clear jobs for next jobs -p (interactive side effect)
-sleep 20 &
+sleep 2 &
 pids=$!
 if	[[ $(jobs -p) != $! ]]
 then	err_exit 'jobs -p not reporting a background job'
 fi
-sleep 20 &
+sleep 2 &
 pids="$pids $!"
 foo()
 {
@@ -325,8 +332,8 @@ foo()
 foo
 kill $pids
 
-[[ $( (trap 'print alarm' ALRM; sleep 4) & sleep 2; kill -ALRM $!; sleep 2; wait) == alarm ]] || err_exit 'ALRM signal not working'
-[[ $($SHELL -c 'trap "" HUP; $SHELL -c "(sleep 2;kill -HUP $$)& sleep 4;print done"') != done ]] && err_exit 'ignored traps not being ignored'
+[[ $( (trap 'print alarm' ALRM; sleep .4) & sleep .2; kill -ALRM $!; sleep .2; wait) == alarm ]] || err_exit 'ALRM signal not working'
+[[ $($SHELL -c 'trap "" HUP; $SHELL -c "(sleep .2;kill -HUP $$)& sleep .4;print done"') != done ]] && err_exit 'ignored traps not being ignored'
 [[ $($SHELL -c 'o=foobar; for x in foo bar; do (o=save);print $o;done' 2> /dev/null ) == $'foobar\nfoobar' ]] || err_exit 'for loop optimization subshell bug'
 command exec 3<> /dev/null
 if	cat /dev/fd/3 >/dev/null 2>&1  || whence mkfifo > /dev/null
@@ -372,9 +379,9 @@ chmod +x $tmp/scriptx
 cat > $tmp/scriptx <<- \EOF
 	myfilter() { x=$(print ok | cat); print  -r -- $SECONDS;}
 	set -o pipefail
-	sleep 3 | myfilter
+	sleep .3 | myfilter
 EOF
-(( $($SHELL $tmp/scriptx) > 2.0 )) && err_exit 'command substitution causes pipefail option to hang'
+(( $($SHELL $tmp/scriptx) > .2 )) && err_exit 'command substitution causes pipefail option to hang'
 exec 3<&-
 ( typeset -r foo=bar) 2> /dev/null || err_exit 'readonly variables set in a subshell cannot unset'
 $SHELL -c 'x=${ print hello;}; [[ $x == hello ]]' 2> /dev/null || err_exit '${ command;} not supported'
@@ -418,7 +425,7 @@ unset foo
 unset foo
 foo=$(false) > /dev/null && err_exit 'failed command substitution with redirection not returning false'
 expected=foreback
-got=$(print -n fore; (sleep 2;print back)&)
+got=$(print -n fore; (sleep .2;print back)&)
 [[ $got == $expected ]] || err_exit "command substitution background process output error -- got '$got', expected '$expected'"
 
 binfalse=$(whence -p false)
@@ -430,19 +437,20 @@ done
 if	env x-a=y >/dev/null 2>&1
 then	[[ $(env 'x-a=y'  $SHELL -c 'env | grep x-a') == *x-a=y* ]] || err_exit 'invalid environment variables not preserved'
 fi
+
 float s=SECONDS
-sleep=$(whence -p sleep)
-for i in 1 2
+for i in .1 .2
 do      print $i
-done | while read sec; do ( $sleep $sec; $sleep $sec) done
-(( (SECONDS-s)  < 4)) && err_exit '"command | while read...done" finishing too fast'
+done | while read sec; do ( "$binsleep" "$sec"; "$binsleep" "$sec") done
+((  (SECONDS-s) < .4)) && err_exit '"command | while read...done" finishing too fast'
 s=SECONDS
 set -o pipefail
 for ((i=0; i < 30; i++))
 do	print hello 2>/dev/null
-	sleep .1
-done |  $sleep 1
-(( (SECONDS-s) < 2 )) || err_exit 'early termination not causing broken pipe'
+	sleep .01
+done |  "$binsleep" .1
+(( (SECONDS-s) < .2 )) || err_exit 'early termination not causing broken pipe'
+
 [[ $({ trap 'print trap' 0; print -n | $(whence -p cat); } & wait $!) == trap ]] || err_exit 'trap on exit not getting triggered'
 var=$({ trap 'print trap' ERR; print -n | $binfalse; } & wait $!)
 [[ $var == trap ]] || err_exit 'trap on ERR not getting triggered'
@@ -479,28 +487,28 @@ set -o pipefail
 float start=$SECONDS end 
 for ((i=0; i < 2; i++))
 do	print foo 2>/dev/null
-	sleep 1.5
+	sleep .15
 done | { read; $bintrue; end=$SECONDS ;}
-(( (SECONDS-start) < 1 )) && err_exit "pipefail not waiting for pipe to finish"
+(( (SECONDS-start) < .1 )) && err_exit "pipefail not waiting for pipe to finish"
 set +o pipefail
-(( (SECONDS-end) > 2 )) &&  err_exit "pipefail causing $bintrue to wait for other end of pipe"
+(( (SECONDS-end) > .2 )) &&  err_exit "pipefail causing $bintrue to wait for other end of pipe"
 
 
 { env A__z=C+SHLVL $SHELL -c : ;} 2> /dev/null || err_exit "SHLVL with wrong attribute fails"
 
 if [[ $bintrue ]]
 then	float t0=SECONDS
-	{ time sleep 1.5 | $bintrue ;} 2> /dev/null
-	(( (SECONDS-t0) < 1 )) && err_exit 'time not waiting for pipeline to complete' 
+	{ time sleep .15 | $bintrue ;} 2> /dev/null
+	(( (SECONDS-t0) < .1 )) && err_exit 'time not waiting for pipeline to complete'
 fi
 
 cat > $tmp/foo.sh <<- \EOF
 	eval "cat > /dev/null  < /dev/null"
-	sleep 1
+	sleep .1
 EOF
 float sec=SECONDS
 . $tmp/foo.sh  | cat > /dev/null
-(( (SECONDS-sec) < .7 ))  && err_exit '. script does not restore output redirection with eval'
+(( (SECONDS-sec) < .07 ))  && err_exit '. script does not restore output redirection with eval'
 
 file=$tmp/foobar
 builtin cat
diff --git a/src/cmd/ksh93/tests/bracket.sh b/src/cmd/ksh93/tests/bracket.sh
index ff1f331d4..46238036c 100755
--- a/src/cmd/ksh93/tests/bracket.sh
+++ b/src/cmd/ksh93/tests/bracket.sh
@@ -130,7 +130,7 @@ fi
 if	[[ ! -w /dev/fd/2 ]]
 then	err_exit "/dev/fd/2 not open for writing"
 fi
-sleep 1
+sleep .01
 > $newer_file
 if	[[ ! $file -ot $newer_file ]]
 then	err_exit "$file should be older than $newer_file"
@@ -235,10 +235,10 @@ done
 rm -rf $file
 {
 [[ -N $file ]] && err_exit 'test -N $tmp/*: st_mtime>st_atime after creat'
-sleep 2
+sleep .02
 print 'hello world'
 [[ -N $file ]] || err_exit 'test -N $tmp/*: st_mtime<=st_atime after write'
-sleep 2
+sleep .02
 read
 [[ -N $file ]] && err_exit 'test -N $tmp/*: st_mtime>st_atime after read'
 } > $file < $file
diff --git a/src/cmd/ksh93/tests/builtins.sh b/src/cmd/ksh93/tests/builtins.sh
index a8fe9dd66..2f43aab5f 100755
--- a/src/cmd/ksh93/tests/builtins.sh
+++ b/src/cmd/ksh93/tests/builtins.sh
@@ -385,7 +385,7 @@ do	arg=$1 val=$2 code=$3
 	shift 3
 	for fmt in '%d' '%g'
 	do	out=$(printf "$fmt" "$arg" 2>/dev/null)
-		err=$(printf "$fmt" "$arg" 2>&1 >/dev/null)
+		err=$(set +x; printf "$fmt" "$arg" 2>&1 >/dev/null)
 		printf "$fmt" "$arg" >/dev/null 2>&1
 		ret=$?
 		[[ $out == $val ]] || err_exit "printf $fmt $arg failed -- expected '$val', got '$out'"
diff --git a/src/cmd/ksh93/tests/coprocess.sh b/src/cmd/ksh93/tests/coprocess.sh
index 0764f9e77..1cc473334 100755
--- a/src/cmd/ksh93/tests/coprocess.sh
+++ b/src/cmd/ksh93/tests/coprocess.sh
@@ -109,7 +109,7 @@ do
 	$cat |&
 	!
 	chmod +x $file
-	sleep 10 |&
+	sleep 1 |&
 	$file 2> /dev/null || err_exit "parent $cat coprocess prevents script coprocess"
 	exec 5<&p 6>&p
 	exec 5<&- 6>&-
@@ -119,15 +119,15 @@ do
 	cop=$!
 	exp=Done
 	print -p $'print hello | '$cat$'\nprint '$exp
-	read -t 5 -p
-	read -t 5 -p
+	read -t 1 -p
+	read -t 1 -p
 	got=$REPLY
 	if	[[ $got != $exp ]]
 	then	err_exit "${SHELL-ksh} $cat coprocess io failed -- got '$got', expected '$exp'"
 	fi
 	exec 5<&p 6>&p
 	exec 5<&- 6>&-
-	{ sleep 4; kill $cop; } 2>/dev/null &
+	{ sleep .4; kill $cop; } 2>/dev/null &
 	spy=$!
 	if	wait $cop 2>/dev/null
 	then	kill $spy 2>/dev/null
@@ -140,15 +140,15 @@ do
 	echo line2 | grep 'line1'
 	} |&
 	SECONDS=0 count=0
-	while	read -p -t 10 line
+	while	read -p -t 1 line
 	do	((count++))
 	done
-	if	(( SECONDS > 8 ))
+	if	(( SECONDS > .8 ))
 	then	err_exit "$cat coprocess read -p hanging (SECONDS=$SECONDS count=$count)"
 	fi
 	wait $!
 	
-	( sleep 3 |& sleep 1 && kill $!; sleep 1; sleep 3 |& sleep 1 && kill $! ) ||
+	( sleep .3 |& sleep .1 && kill $!; sleep .1; sleep .3 |& sleep .1 && kill $! ) ||
 		err_exit "$cat coprocess cleanup not working correctly"
 	{ : |& } 2>/dev/null ||
 		err_exit "subshell $cat coprocess lingers in parent"
@@ -166,7 +166,7 @@ do
 			wait $!
 		done
 		print
-	) 2>/dev/null | read -t 10 r
+	) 2>/dev/null | read -t 1 r
 	[[ $r == $e ]] || err_exit "$cat coprocess timing bug -- expected $e, got '$r'"
 	
 	r=
@@ -174,21 +174,21 @@ do
 		integer i
 		for ((i = 1; i <= N; i++))
 		do	print $i |&
-			sleep 0.01
+			sleep 0.001
 			r=$r$($cat <&p)
 			wait $!
 		done
 		print $r
-	) 2>/dev/null | read -t 10 r
+	) 2>/dev/null | read -t 1 r
 	[[ $r == $e ]] || err_exit "$cat coprocess command substitution bug -- expected $e, got '$r'"
 	
 	(
 		$cat |&
-		sleep 0.01
+		sleep 0.001
 		exec 6>&p
 		print -u6 ok
 		exec 6>&-
-		sleep 2
+		sleep .2
 		kill $! 2> /dev/null
 	) && err_exit "$cat coprocess with subshell would hang"
 	for sig in IOT ABRT
@@ -198,12 +198,12 @@ do
 					pid=\$!
 					trap "print TRAP" \$sig
 					(
-						sleep 2
+						sleep .2
 						kill -\$sig \$\$
-						sleep 2
+						sleep .2
 						kill -\$sig \$\$
 						kill \$pid
-						sleep 2
+						sleep .2
 						kill \$\$
 					) &
 					while	read -p || ((\$? > 256))
@@ -218,7 +218,7 @@ do
 	done
 	
 	trap 'sleep_pid=; kill $pid; err_exit "$cat coprocess 1 hung"' TERM
-	{ sleep 5; kill $$; } &
+	{ sleep .5; kill $$; } &
 	sleep_pid=$!
 	$cat |&
 	pid=$!
@@ -232,7 +232,7 @@ do
 	[[ $sleep_pid ]] && kill $sleep_pid
 	
 	trap 'sleep_pid=; kill $pid; err_exit "$cat coprocess 2 hung"' TERM
-	{ sleep 5; kill $$; } &
+	{ sleep .5; kill $$; } &
 	sleep_pid=$!
 	$cat |&
 	pid=$!
@@ -244,7 +244,7 @@ do
 	[[ $sleep_pid ]] && kill $sleep_pid
 	
 	trap 'sleep_pid=; kill $pid; err_exit "$cat coprocess 3 hung"' TERM
-	{ sleep 5; kill $$; } &
+	{ sleep .5; kill $$; } &
 	sleep_pid=$!
 	$cat |&
 	pid=$!
diff --git a/src/cmd/ksh93/tests/functions.sh b/src/cmd/ksh93/tests/functions.sh
index 83df8f10d..562821000 100755
--- a/src/cmd/ksh93/tests/functions.sh
+++ b/src/cmd/ksh93/tests/functions.sh
@@ -981,10 +981,17 @@ function _Dbg_debug_trap_handler
 	done
 }
 
+(
+: 'Disabling xtrace while running _Dbg_* functions'
+set +x	# TODO: the _Dbg_* functions are incompatible with xtrace. To expose the regression
+	# test failures, run 'bin/shtests -x -p functions'. Is this a bug in ksh?
 ((baseline=LINENO+2))
 trap '_Dbg_debug_trap_handler' DEBUG
 .  $tmp/debug foo bar
 trap '' DEBUG
+exit $Errors
+)
+Errors=$?
 
 caller() {
   integer .level=.sh.level .max=.sh.level-1
diff --git a/src/cmd/ksh93/tests/io.sh b/src/cmd/ksh93/tests/io.sh
index d84491247..8b2721604 100755
--- a/src/cmd/ksh93/tests/io.sh
+++ b/src/cmd/ksh93/tests/io.sh
@@ -99,6 +99,7 @@ fi
 
 # 2004-11-25 ancient /dev/fd/N redirection bug fix
 got=$(
+	set +x
 	{
 		print -n 1
 		print -n 2 > ${FDFS[fdfs].dir}/2
@@ -338,16 +339,16 @@ read -n3 a <<!
 abcdefg
 !
 [[ $a == abc ]] || err_exit 'read -n3 here-document not working'
-(print -n a; sleep 1; print -n bcde) | { read -N3 a; read -N1 b;}
+(print -n a; sleep .1; print -n bcde) | { read -N3 a; read -N1 b;}
 [[ $a == abc ]] || err_exit 'read -N3 from pipe not working'
 [[ $b == d ]] || err_exit 'read -N1 from pipe not working'
-(print -n a; sleep 1; print -n bcde) 2>/dev/null |read -n3 a
+(print -n a; sleep .1; print -n bcde) 2>/dev/null |read -n3 a
 [[ $a == a ]] || err_exit 'read -n3 from pipe not working'
 if	mkfifo $tmp/fifo 2> /dev/null
-then	(print -n a; sleep 2; print -n bcde) > $tmp/fifo &
+then	(print -n a; sleep .2; print -n bcde) > $tmp/fifo &
 	{
-	read -u5 -n3 -t3 a || err_exit 'read -n3 from fifo timed out'
-	read -u5 -n1 -t3 b || err_exit 'read -n1 from fifo timed out'
+	read -u5 -n3 -t1 a || err_exit 'read -n3 from fifo timed out'
+	read -u5 -n1 -t1 b || err_exit 'read -n1 from fifo timed out'
 	} 5< $tmp/fifo
 	exp=a
 	got=$a
@@ -358,10 +359,10 @@ then	(print -n a; sleep 2; print -n bcde) > $tmp/fifo &
 	rm -f $tmp/fifo
 	wait
 	mkfifo $tmp/fifo 2> /dev/null
-	(print -n a; sleep 2; print -n bcde) > $tmp/fifo &
+	(print -n a; sleep .2; print -n bcde) > $tmp/fifo &
 	{
-	read -u5 -N3 -t3 a || err_exit 'read -N3 from fifo timed out'
-	read -u5 -N1 -t3 b || err_exit 'read -N1 from fifo timed out'
+	read -u5 -N3 -t1 a || err_exit 'read -N3 from fifo timed out'
+	read -u5 -N1 -t1 b || err_exit 'read -N1 from fifo timed out'
 	} 5< $tmp/fifo
 	exp=abc
 	got=$a
@@ -373,16 +374,16 @@ then	(print -n a; sleep 2; print -n bcde) > $tmp/fifo &
 fi
 (
 	print -n 'prompt1: '
-	sleep .1
+	sleep .01
 	print line2
-	sleep .1
+	sleep .01
 	print -n 'prompt2: '
-	sleep .1
+	sleep .01
 ) | {
-	read -t2 -n 1000 line1
-	read -t2 -n 1000 line2
-	read -t2 -n 1000 line3
-	read -t2 -n 1000 line4
+	read -t1 -n 1000 line1
+	read -t1 -n 1000 line2
+	read -t1 -n 1000 line3
+	read -t1 -n 1000 line4
 }
 [[ $? == 0 ]]		 	&& err_exit 'should have timed out'
 [[ $line1 == 'prompt1: ' ]] 	|| err_exit "line1 should be 'prompt1: '"
@@ -410,7 +411,7 @@ do	a=$1
 	shift 4
 	for ((i = 0; i < 2; i++))
 	do	for lc_all in C $lc_utf8
-		do	g=$(LC_ALL=$lc_all $SHELL -c "{ print -n '$a'; sleep 0.2; print -n '$b'; sleep 0.2; } | { read ${o[i]} a; print -n \$a; read a; print -n \ \$a; }")
+		do	g=$(LC_ALL=$lc_all $SHELL -c "{ print -n '$a'; sleep .02; print -n '$b'; sleep .02; } | { read ${o[i]} a; print -n \$a; read a; print -n \ \$a; }")
 			[[ $g == "${e[i]}" ]] || err_exit "LC_ALL=$lc_all read ${o[i]} from pipe '$a $b' failed -- expected '${e[i]}', got '$g'"
 		done
 	done
@@ -437,12 +438,14 @@ then	export LC_ALL=$lc_utf8
 	fi
 fi
 
-exec 3<&2
 file=$tmp/file
+(
+: disabling xtrace so we can redirect stderr for this test
+set +x
 redirect 5>$file 2>&5
 print -u5 -f 'This is a test\n'
 print -u2 OK
-exec 2<&3
+)
 exp=$'This is a test\nOK'
 got=$(< $file)
 [[ $got == $exp ]] || err_exit "output garbled when stderr is duped -- expected $(printf %q "$exp"), got $(printf %q "$got")"
diff --git a/src/cmd/ksh93/tests/locale.sh b/src/cmd/ksh93/tests/locale.sh
index c95635910..b43a5f2cb 100755
--- a/src/cmd/ksh93/tests/locale.sh
+++ b/src/cmd/ksh93/tests/locale.sh
@@ -200,11 +200,11 @@ got="$(<out)"
 # multibyte identifiers
 
 exp=OK
-got=$(LC_ALL=C.UTF-8 $SHELL -c $'\u[5929]=OK; print ${\u[5929]}' 2>&1)
+got=$(set +x; LC_ALL=C.UTF-8 $SHELL -c $'\u[5929]=OK; print ${\u[5929]}' 2>&1)
 [[ $got == "$exp" ]] || err_exit "multibyte variable definition/expansion failed -- expected '$exp', got '$got'"
-got=$(LC_ALL=C.UTF-8 $SHELL -c $'function \u[5929]\n{\nprint OK;\n}; \u[5929]' 2>&1)
+got=$(set +x; LC_ALL=C.UTF-8 $SHELL -c $'function \u[5929]\n{\nprint OK;\n}; \u[5929]' 2>&1)
 [[ $got == "$exp" ]] || err_exit "multibyte ksh function definition/execution failed -- expected '$exp', got '$got'"
-got=$(LC_ALL=C.UTF-8 $SHELL -c $'\u[5929]()\n{\nprint OK;\n}; \u[5929]' 2>&1)
+got=$(set +x; LC_ALL=C.UTF-8 $SHELL -c $'\u[5929]()\n{\nprint OK;\n}; \u[5929]' 2>&1)
 [[ $got == "$exp" ]] || err_exit "multibyte posix function definition/execution failed -- expected '$exp', got '$got'"
 
 # this locale is supported by ast on all platforms
diff --git a/src/cmd/ksh93/tests/options.sh b/src/cmd/ksh93/tests/options.sh
index a8abb2d86..95a467530 100755
--- a/src/cmd/ksh93/tests/options.sh
+++ b/src/cmd/ksh93/tests/options.sh
@@ -73,7 +73,7 @@ then
 		got=$(printf %q "$got")
 		err_exit "\$ENV file &>/dev/null does not redirect stdout -- expected '', got $got"
 	fi
-	got=$($SHELL -E -c : 2>&1 >/dev/null)
+	got=$(set +x; $SHELL -E -c : 2>&1 >/dev/null)
 	if	[[ $got != *nonstandard* || $got == *$'\n'* ]]
 	then
 		got=$(printf %q "$got")
@@ -151,11 +151,11 @@ then
 else
 	[[ $(print env_hit | HOME=$tmp $SHELL 2>&1) == "OK" ]] &&
 		err_exit 'nointeractive shell reads $HOME/.kshrc file'
-	[[ $(print env_hit | HOME=$tmp $SHELL -E 2>&1) == "OK" ]] ||
+	[[ $(set +x; print env_hit | HOME=$tmp $SHELL -E 2>&1) == "OK" ]] ||
 		err_exit '-E ignores $HOME/.kshrc file'
 	[[ $(print env_hit | HOME=$tmp $SHELL +E 2>&1) == "OK" ]] &&
 		err_exit '+E reads $HOME/.kshrc file'
-	[[ $(print env_hit | HOME=$tmp $SHELL --rc 2>&1) == "OK" ]] ||
+	[[ $(set +x; print env_hit | HOME=$tmp $SHELL --rc 2>&1) == "OK" ]] ||
 		err_exit '--rc ignores $HOME/.kshrc file'
 	[[ $(print env_hit | HOME=$tmp $SHELL --norc 2>&1) == "OK" ]] &&
 		err_exit '--norc reads $HOME/.kshrc file'
@@ -368,7 +368,7 @@ pipeline=(
 	( nopipefail=1 pipefail=1 command='true|true|false' )
 	( nopipefail=1 pipefail=1 command='false|false|false' )
 	( nopipefail=0 pipefail=0 command='true|true|true' )
-	( nopipefail=0 pipefail=0 command='print hi|(sleep 1;"$bincat")>/dev/null' )
+	( nopipefail=0 pipefail=0 command='print hi|(sleep .1;"$bincat")>/dev/null' )
 )
 set --nopipefail
 for ((i = 0; i < ${#pipeline[@]}; i++ ))
@@ -443,10 +443,10 @@ export ENV= PS1="(:$$:)"
 histfile=$tmp/history
 exp=$(HISTFILE=$histfile $SHELL -c $'function foo\n{\ncat\n}\ntype foo')
 for var in HISTSIZE HISTFILE
-do	got=$( ( HISTFILE=$histfile $SHELL +E -ic $'unset '$var$'\nfunction foo\n{\ncat\n}\ntype foo\nexit' ) 2>&1 )
+do	got=$( set +x; ( HISTFILE=$histfile $SHELL +E -ic $'unset '$var$'\nfunction foo\n{\ncat\n}\ntype foo\nexit' ) 2>&1 )
 	got=${got##*"$PS1"} 
 	[[ $got == "$exp" ]] || err_exit "function definition inside (...) with $var unset fails -- got '$got', expected '$exp'"
-	got=$( { HISTFILE=$histfile $SHELL +E -ic $'unset '$var$'\nfunction foo\n{\ncat\n}\ntype foo\nexit' ;} 2>&1 )
+	got=$( set +x; { HISTFILE=$histfile $SHELL +E -ic $'unset '$var$'\nfunction foo\n{\ncat\n}\ntype foo\nexit' ;} 2>&1 )
 	got=${got##*"$PS1"} 
 	[[ $got == "$exp" ]] || err_exit "function definition inside {...;} with $var unset fails -- got '$got', expected '$exp'"
 done
diff --git a/src/cmd/ksh93/tests/path.sh b/src/cmd/ksh93/tests/path.sh
index 8c37e3a71..70d0b0cad 100755
--- a/src/cmd/ksh93/tests/path.sh
+++ b/src/cmd/ksh93/tests/path.sh
@@ -342,7 +342,7 @@ function foo
 
 # whence -q bug fix
 $SHELL -c 'whence -q cat' & pid=$!
-sleep 3
+sleep .1
 kill $! 2> /dev/null && err_exit 'whence -q appears to be hung'
 
 FPATH=$PWD
diff --git a/src/cmd/ksh93/tests/shtests b/src/cmd/ksh93/tests/shtests
index 138be48f0..fdbcccf96 100755
--- a/src/cmd/ksh93/tests/shtests
+++ b/src/cmd/ksh93/tests/shtests
@@ -207,7 +207,7 @@ done
 shift $OPTIND-1
 
 if	(( debug )) || [[ $trace ]]
-then	export PS4=':$LINENO: '
+then	export PS4='+ [${SECONDS:+${SECONDS%????}s|}${.sh.subshell:+S${.sh.subshell},}${.sh.file:+${.sh.file#${.sh.file%/*/*}/},}${.sh.fun:+${.sh.fun},}${LINENO:+L$LINENO,}e$?] '
 	if	(( debug ))
 	then	set -x
 	fi
diff --git a/src/cmd/ksh93/tests/sigchld.sh b/src/cmd/ksh93/tests/sigchld.sh
index 3b352652c..30ba7637d 100755
--- a/src/cmd/ksh93/tests/sigchld.sh
+++ b/src/cmd/ksh93/tests/sigchld.sh
@@ -26,7 +26,7 @@ function err_exit
 
 alias err_exit='err_exit $LINENO'
 
-float DELAY=${1:-0.2}
+float DELAY=${1:-0.02}
 integer FOREGROUND=10 BACKGROUND=2 Errors=0
 
 tmp=$(
@@ -82,7 +82,7 @@ then
 		integer running=0 maxrunning=0
 		trap "((running--))" CHLD
 		for ((i=0; i<JOBCOUNT; i++))
-		do	sleep 1 &
+		do	sleep .1 &
 			if	((++running > maxrunning))
 			then	((maxrunning=running))
 			fi
@@ -101,13 +101,13 @@ then
 			unset proc[\$!]
 		" CHLD
 
-		{ sleep 3; print a; exit 1; } &
+		{ sleep .3; print a; exit 1; } &
 		proc[$!]=( name=a status=1 )
 
-		{ sleep 2; print b; exit 2; } &
+		{ sleep .2; print b; exit 2; } &
 		proc[$!]=( name=b status=2 )
 
-		{ sleep 1; print c; exit 3; } &
+		{ sleep .1; print c; exit 3; } &
 		proc[$!]=( name=c status=3 )
 
 		while	(( ${#proc[@]} ))
@@ -120,8 +120,8 @@ then
 fi
 
 {
-got=$( ( sleep 1;print $'\n') | $SHELL -c 'function handler { : ;}
-	trap handler CHLD; sleep .3 & IFS= read; print good')
+got=$( ( sleep .1;print $'\n') | $SHELL -c 'function handler { : ;}
+	trap handler CHLD; sleep .03 & IFS= read; print good')
 } 2> /dev/null
 [[ $got == good ]] || err_exit 'SIGCLD handler effects read behavior'
 
@@ -129,9 +129,9 @@ set -- $(
 	(
 	$SHELL -xc $'
 		trap \'wait $!; print $! $?\' CHLD
-		{ sleep 0.1; exit 9; } &
+		{ sleep 0.01; exit 9; } &
 		print $!
-		sleep 0.5
+		sleep 0.05
 	'
 	) 2>/dev/null; print $?
 )
@@ -155,11 +155,11 @@ done
 (( d==2000 )) ||  err_exit "trap '' CHLD  causes side effects d=$d"
 trap - CHLD
 
-x=$($SHELL 2> /dev/null -ic '/dev/null/notfound; sleep .5 & sleep 1;jobs')
+x=$($SHELL 2> /dev/null -ic '/dev/null/notfound; sleep .05 & sleep .1;jobs')
 [[ $x == *Done* ]] || err_exit 'SIGCHLD blocked after notfound'
-x=$($SHELL 2> /dev/null  -ic 'kill -0 12345678901234567876; sleep .5 & sleep 1;jobs')
+x=$($SHELL 2> /dev/null  -ic 'kill -0 12345678901234567876; sleep .05 & sleep .1;jobs')
 [[ $x == *Done* ]] || err_exit 'SIGCHLD blocked after error message'
-print 'set -o monitor;sleep .5 & sleep 1;jobs' > $tmp/foobar
+print 'set -o monitor;sleep .05 & sleep .1;jobs' > $tmp/foobar
 chmod +x $tmp/foobar
 x=$($SHELL  -c "echo | $tmp/foobar")
 [[ $x == *Done* ]] || err_exit 'SIGCHLD blocked for script at end of pipeline'
diff --git a/src/cmd/ksh93/tests/signal.sh b/src/cmd/ksh93/tests/signal.sh
index ae6021c12..260ef7918 100755
--- a/src/cmd/ksh93/tests/signal.sh
+++ b/src/cmd/ksh93/tests/signal.sh
@@ -56,7 +56,8 @@ do	if	! n=$(kill -l $s 2>/dev/null)
 done
 
 (
-	set --pipefail
+	: disabling xtrace for this test
+	set +x --pipefail
 	{
 		$SHELL 2> out2 <<- \EOF
 			g=false
@@ -67,6 +68,7 @@ done
 		EOF
 	} | head > /dev/null
 	(( $? == 0)) ||   err_exit "SIGPIPE with wrong error code $?"
+	# The below is kind of bogus as the err_exit from a bg job is never counterd. But see extra check below.
 	[[ $(<out2) == $'PIPED\nPIPED' ]] || err_exit 'SIGPIPE output on standard error is not correct'
 ) &
 cop=$!
@@ -74,7 +76,7 @@ cop=$!
 spy=$!
 if	wait $cop 2>/dev/null
 then	kill $spy 2>/dev/null
-else	err_exit "pipe with --pipefail PIPE trap hangs"
+else	err_exit "pipe with --pipefail PIPE trap hangs or produced an error"
 fi
 wait
 rm -f out2
diff --git a/src/cmd/ksh93/tests/subshell.sh b/src/cmd/ksh93/tests/subshell.sh
index a393b8db5..37da42fc4 100755
--- a/src/cmd/ksh93/tests/subshell.sh
+++ b/src/cmd/ksh93/tests/subshell.sh
@@ -19,14 +19,15 @@
 ########################################################################
 function err_exit
 {
-	print -u$Error_fd -n "\t"
-	print -u$Error_fd -r ${Command}[$1]: "${@:2}"
+	print -u2 -n "\t"
+	print -u2 -r ${Command}[$1]: "${@:2}"
 	(( Errors+=1 ))
 }
 alias err_exit='err_exit $LINENO'
 
 Command=${0##*/}
-integer Errors=0 Error_fd=2
+integer Errors=0
+typeset -F SECONDS  # for fractional seconds in PS4
 
 tmp=$(
 	d=${TMPDIR:-/tmp}/ksh93.subshell.$$.${RANDOM:-0}
@@ -40,6 +41,13 @@ trap 'cd / && rm -rf "$tmp"' EXIT
 builtin getconf
 bincat=$(PATH=$(getconf PATH) whence -p cat)
 binecho=$(PATH=$(getconf PATH) whence -p echo)
+# make an external 'sleep' command that supports fractional seconds
+binsleep=$tmp/.sleep.sh  # hide to exclude from simple wildcard expansion
+cat >"$binsleep" <<EOF
+#!$SHELL
+sleep "\$@"
+EOF
+chmod +x "$binsleep"
 
 z=()
 z.foo=( [one]=hello [two]=(x=3 y=4) [three]=hi)
@@ -102,9 +110,6 @@ unset l
 )
 [[ ${l+foo} != foo ]] || err_exit 'l should be unset'
 
-Error_fd=9
-eval "exec $Error_fd>&2 2>/dev/null"
-
 TEST_notfound=notfound
 while	whence $TEST_notfound >/dev/null 2>&1
 do	TEST_notfound=notfound-$RANDOM
@@ -220,7 +225,7 @@ do	for TEST_exec in '' 'exec'
 			sleep 2
 			kill -KILL $$
 		} &
-		'"$TEST_test"'
+		{ '"$TEST_test"'; } 2>/dev/null
 		kill $!
 		print ok
 		')
@@ -394,7 +399,7 @@ do	cat $tmp/buf $tmp/buf > $tmp/tmp
 		wait $m
 		h=$?
 		kill -9 $k
-		wait $k
+		{ wait $k; } 2>/dev/null  # suppress 'wait: $pid: Killed'
 		got=$(<$tmp/out)
 		if	[[ ! $got ]] && (( h ))
 		then	got=HUNG
@@ -427,7 +432,7 @@ done
 # specifics -- there's more?
 
 {
-	cmd='{ exec 5>/dev/null; print "$(eval ls -d . 2>&1 1>&5)"; } >$tmp/out &'
+	cmd='{ exec 5>/dev/null; print "$(set +x; eval ls -d . 2>&1 1>&5)"; } >$tmp/out &'
 	eval $cmd
 	m=$!
 	{ sleep 4; kill -9 $m; } &
@@ -447,13 +452,11 @@ then	err_exit "eval '$cmd' failed -- expected '$exp', got '$got'"
 fi
 
 float t1=$SECONDS
-sleep=$(whence -p sleep)
-if	[[ $sleep ]]
-then
-	$SHELL -c "( $sleep 5 </dev/null >/dev/null 2>&1 & );exit 0" | cat 
-	(( (SECONDS-t1) > 4 )) && err_exit '/bin/sleep& in subshell hanging'
-	((t1=SECONDS))
-fi
+
+$SHELL -c '( "$1" 5 </dev/null >/dev/null 2>&1 & );exit 0' x "$binsleep" | cat 
+(( (SECONDS-t1) > 4 )) && err_exit '/bin/sleep& in subshell hanging'
+((t1=SECONDS))
+
 $SHELL -c '( sleep 5 </dev/null >/dev/null 2>&1 & );exit 0' | cat 
 (( (SECONDS-t1) > 4 )) && err_exit 'sleep& in subshell hanging'
 
@@ -483,7 +486,7 @@ $SHELL -c 'sleep 20 & pid=$!; { x=$( ( seq 60000 ) );kill -9 $pid;}&;wait $pid'
 
 (.sh.foo=foobar)
 [[ ${.sh.foo} == foobar ]] && err_exit '.sh subvariables in subshells remain set'
-[[ $($SHELL -c 'print 1 | : "$("$bincat" <("$bincat"))"') ]] && err_exit 'process substitution not working correctly in subshells'
+[[ $(export bincat; $SHELL -c 'print 1 | : "$("$bincat" <("$bincat"))"') ]] && err_exit 'process substitution not working correctly in subshells'
 
 # config hang bug
 integer i
@@ -542,7 +545,7 @@ $SHELL <<- \EOF
 	(( ${#out} == 96011 )) || err_exit "\${#out} is ${#out} should be 96011"
 EOF
 } & pid=$!
-$SHELL -c "{ sleep 4 && kill $pid ;}" 2> /dev/null
+$SHELL -c "{ sleep .4 && kill $pid ;}" 2> /dev/null
 (( $? == 0 )) &&  err_exit 'process has hung'
 
 {
@@ -613,7 +616,7 @@ $SHELL <<- \EOF
 	wc=$(whence wc) head=$(whence head)
 	print > /dev/null  $( ( $head -c 1 /dev/zero | ( $wc -c) 3>&1 ) 3>&1) &
 	pid=$!
-	sleep 2
+	sleep .2
 	kill -9 $! 2> /dev/null && err_exit '/dev/zero in command substitution hangs'
 	wait $!
 EOF
@@ -685,13 +688,13 @@ expect=$'sub3\nok_nonexistent\nsub2\nsub1\nmainfunction'
 
 alias al="echo 'mainalias'"
 
-(unalias al; alias al >/dev/null) && err_exit 'alias fails to be unset in subshell'
+(unalias al; alias al 2>/dev/null) && err_exit 'alias fails to be unset in subshell'
 
-v=$(unalias al; alias al >/dev/null) && err_exit 'alias fails to be unset in comsub'
+v=$(unalias al; alias al 2>/dev/null) && err_exit 'alias fails to be unset in comsub'
 
 [[ $(eval 'al') == 'mainalias' ]] || err_exit 'main alias fails to survive unset in subshell(s)'
 
-v=${ eval 'al'; unalias al 2>&1; } && [[ $v == 'mainalias' ]] && ! alias al >/dev/null \
+v=${ eval 'al'; unalias al 2>&1; } && [[ $v == 'mainalias' ]] && ! alias al 2>/dev/null \
 || err_exit 'main shell alias wrongly survives unset within ${ ...; }'
 
 # ...alias can be redefined in subshell
diff --git a/src/cmd/ksh93/tests/substring.sh b/src/cmd/ksh93/tests/substring.sh
index d33b7f9a8..b74c18143 100755
--- a/src/cmd/ksh93/tests/substring.sh
+++ b/src/cmd/ksh93/tests/substring.sh
@@ -26,7 +26,10 @@ function err_exit
 alias err_exit='err_exit $LINENO'
 
 Command=${0##*/}
-integer Errors=0 j=4
+integer Errors=0
+tmpPS4='+ [temp_PS4|L$LINENO|e$?] '  # used to avoid interference to ${.sh.match} from $PS4 set by shtests
+
+integer j=4
 base=/home/dgk/foo//bar
 string1=$base/abcabcabc
 if	[[ ${string1:0} != "$string1" ]]
@@ -261,6 +264,9 @@ foo='foo+bar+'
 [[ $(print -r -- ${foo//+/"|"}) != 'foo|bar|' ]] && err_exit '${foobar//+/"|"}'
 [[ $(print -r -- "${foo//+/'|'}") != 'foo|bar|' ]] && err_exit '"${foobar//+/'"'|'"'}"'
 [[ $(print -r -- "${foo//+/"|"}") != 'foo|bar|' ]] && err_exit '"${foobar//+/"|"}"'
+
+(
+PS4=$tmpPS4
 unset x
 x=abcedfg
 : ${x%@(d)f@(g)}
@@ -270,6 +276,10 @@ x=abcedfg
 x=abcedddfg
 : ${x%%+(d)f@(g)}
 [[ ${.sh.match[1]} == ddd ]] || err_exit '.sh.match[1] not ddd'
+exit $Errors
+)
+Errors=$?
+
 unset a b
 a='\[abc @(*) def\]'
 b='[abc 123 def]'
@@ -296,10 +306,16 @@ integer i
 for((i=0; i < ${#string}; i++))
 do	pattern+='@(?)'
 done
+
+(
+PS4=$tmpPS4
 [[ $(string=$string $SHELL -c  ": \${string/$pattern/}; print \${.sh.match[26]}") == Z ]] || err_exit -u2 'sh.match[26] not Z'
 : ${string/$pattern/}
 (( ${#.sh.match[@]} == 53 )) || err_exit '.sh.match has wrong number of elements'
 [[ ${.sh.match[@]:2:4} == 'B C D E'  ]] || err_exit '${.sh.match[@]:2:4} incorrect'
+exit $Errors
+)
+Errors=$?
 
 D=$';' E=$'\\\\' Q=$'"' S=$'\'' M='nested pattern substitution failed'
 
@@ -497,7 +513,7 @@ pattern=00
 var=100
 [[ $( print $(( ${var%%00} )) ) == 1 ]] || err_exit "arithmetic with embedded patterns fails"
 [[ $( print $(( ${var%%$pattern} )) ) == 1 ]] || err_exit "arithmetic with embedded pattern variables fails"
-if	[[ ax == @(a)* ]] && [[ ${.sh.match[1]:0:${#.sh.match[1]}}  != a ]]
+if	(PS4=$tmpPS4; [[ ax == @(a)* ]] && [[ ${.sh.match[1]:0:${#.sh.match[1]}}  != a ]])
 then	err_exit '${.sh.match[1]:1:${#.sh.match[1]}} not expanding correctly'
 fi
 
@@ -586,6 +602,9 @@ got=$($SHELL -c 'A=""; B="B"; for I in ${A[@]} ${B[@]}; do echo "\"$I\""; done')
 A='|'
 [[ $A == $A ]] || err_exit 'With A="|",  [[ $A == $A ]] does not match'
 
+(
+PS4=$tmpPS4
+
 x="111 222 333 444 555 666"
 [[ $x == ~(E)(...).(...).(...) ]]
 [[ -v .sh.match[0] ]] ||   err_exit '[[ -v .sh.match[0] ]] should be true'
@@ -597,6 +616,10 @@ x="foo bar"
 dummy=${x/~(E)(*)/}
 [[ ${ print -v .sh.match;} ]] && err_exit 'print -v should show .sh.match empty when there are no matches'
 
+exit $Errors
+)
+Errors=$?
+
 if	$SHELL -c 'set 1 2 3 4 5 6 7 8 9 10 11 12; : ${##[0-9]}' 2>/dev/null
 then	set 1 2 3 4 5 6 7 8 9 10 11 12
 	[[ ${##[0-9]} == 2 ]] || err_exit '${##[0-9]} should be 2 with $#==12'
@@ -614,16 +637,21 @@ fi
 
 function foo
 {
-	typeset x="123 456 789 abc"
+	typeset PS4=$tmpPS4 x="123 456 789 abc"
 	typeset dummy="${x/~(E-g)([[:digit:]][[:digit:]])((X)|([[:digit:]]))([[:blank:]])/_}"
 	exp=$'(\n\t[0]=\'123 \'\n\t[1]=12\n\t[2]=3\n\t[4]=3\n\t[5]=\' \'\n)'
 	[[ $(print -v .sh.match) == "$exp" ]] || err_exit '.sh.match not correct with alternations'
 }
 foo
 
+(
+PS4=$tmpPS4
 x="a 1 b"
 d=${x/~(E)(([[:digit:]])[[:space:]]*|([[:alpha:]]))/X}
 [[ $(print -v .sh.match) == $'(\n\t[0]=a\n\t[1]=a\n\t[3]=a\n)' ]] || err_exit '.sh.match not sparse'
+exit $Errors
+)
+Errors=$?
 
 unset v
 typeset -a arr=( 0 1 2 3 4 )
@@ -654,11 +682,16 @@ do	err_exit "\${@:0:-1} should not generate ${v:-empty_string}"
 	break
 done
 
+(
+PS4=$tmpPS4
 unset v d
 v=abbbc
 d="${v/~(E)b{2,4}/dummy}"
 [[ ${.sh.match} == bbb ]] || err_exit '.sh.match wrong after ${s/~(E)b{2,4}/dummy}'
 [[ $d == adummyc ]] || err_exit '${s/~(E)b{2,4}/dummy} not working'
+exit $Errors
+)
+Errors=$?
 
-
+# ======
 exit $((Errors<125?Errors:125))
diff --git a/src/cmd/ksh93/tests/variables.sh b/src/cmd/ksh93/tests/variables.sh
index cd7aaa364..ecf0347d2 100755
--- a/src/cmd/ksh93/tests/variables.sh
+++ b/src/cmd/ksh93/tests/variables.sh
@@ -47,9 +47,10 @@ if	(( RANDOM==RANDOM || $RANDOM==$RANDOM ))
 then	err_exit RANDOM variable not working
 fi
 # SECONDS
-sleep 3
-if	(( SECONDS < 2 ))
-then	err_exit SECONDS variable not working
+let SECONDS=0.0
+sleep .001
+if	(( SECONDS < .001 ))
+then	err_exit "either 'sleep' or \$SECONDS not working"
 fi
 # _
 set abc def
@@ -217,6 +218,7 @@ x error"
 	then	err_exit "\${#$i} not correct"
 	fi
 done
+kill -s 0 $! || err_exit '$! does not point to latest asynchronous process'
 kill $!
 unset x
 CDPATH=/
@@ -433,12 +435,12 @@ fi
 function foo
 {
 	typeset SECONDS=0
-	sleep 1.5
+	sleep .002
 	print $SECONDS
 
 }
 x=$(foo)
-(( x >1 && x < 2 ))
+(( x >.001 && x < .01 ))
 '
 } 2> /dev/null   || err_exit 'SECONDS not working in function'
 cat > $tmp/script <<-\!