Fix some bugs in the regression tests and add more regression tests (#295)

src/cmd/ksh93/tests/{basic.sh,builtins.sh,shtests}:
- Redirect error output from the ulimit builtin to silence irrelevant
  errors in the regression tests (these errors may occur when a
  command such as 'ulimit -t 4' is run before the regression tests).
- Shellquote the error messages from the getconf regression tests.

src/cmd/ksh93/tests/{arrays,io,variables}.sh:
- Backport the ksh2020 regression tests for the following bugs:
  https://github.com/att/ast/issues/23
  https://github.com/att/ast/issues/203
  https://github.com/att/ast/issues/472
  https://github.com/att/ast/issues/492
- Minor fix to POSIX mode regression tests in ksh93v-. In ksh93v-,
  [[ -o ?posix ]] doesn't return an error (because it's implemented
  in the bash mode). However, 'set -o posix' will fail in ksh93v-
  if it's not in bash compatibility mode, which causes this test
  script to exit prematurely.

src/cmd/ksh93/tests/{basic,pty}.sh:
- Add test for https://github.com/att/ast/issues/1461
- The ksh2020 fix for [ -t 1 ] in non-forking command substitutions
  caused the following bug in interactive shells:
    $ ( [ -t 1 ]; echo $? )
    1  # Always fails
  To avoid introducing this bug, this commit adds a regression
  test for it.

src/cmd/ksh93/tests/functions.sh:
- Add test for https://github.com/att/ast/issues/1160
  Put the test to the start of functions.sh (if it's at the end
  of the script, it refuses to fail under ksh2020). Output from
  this regression test when run against ksh2020:
    functions.sh[46]: eval'ing function dumps function body to
    stdout (got $' { eval "bar() { FAILURE; }"; }\n { FAILURE; }')

src/cmd/ksh93/tests/arrays.sh

@@ -729,5 +729,12 @@ do
 		"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
 done
 
+# ======
+# https://github.com/att/ast/issues/23
+unset foo bar
+typeset -a foo=([1]=w [2]=x) bar=(a b c)
+foo+=("${bar[@]}")
+[[ $(typeset -p foo) == 'typeset -a foo=([1]=w [2]=x [3]=a [4]=b [5]=c)' ]] || err_exit 'Appending does not work if array contains empty indexes'
+
 # ======
 exit $((Errors<125?Errors:125))

src/cmd/ksh93/tests/basic.sh

@@ -795,7 +795,7 @@ trap - DEBUG  # bug compat
 # In ksh93v- and ksh2020 EXIT traps don't work in forked subshells
 # https://github.com/att/ast/issues/1452
 exp="forked subshell EXIT trap okay"
-got="$(ulimit -t unlimited; trap 'echo forked subshell EXIT trap okay' EXIT)"
+got="$(ulimit -t unlimited 2> /dev/null; trap 'echo forked subshell EXIT trap okay' EXIT)"
 [[ $got == $exp ]] || err_exit "EXIT trap did not trigger in forked subshell" \
 	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
 

src/cmd/ksh93/tests/builtins.sh

@@ -40,14 +40,14 @@ got=$(getconf -l | awk '{ gsub(/=.*/, "") } /[[:upper:]]/ { print }')
 exp="GETCONF=\"$bingetconf\""
 got=$(getconf -q | grep 'GETCONF=')
 [[ $exp == "$got" ]] || err_exit "'getconf -q' fails to quote string values" \
-	"(expected $exp, got $got)"
+	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
 
 # The -n option should only return matching names.
 # https://github.com/ksh93/ksh/issues/279
 exp="GETCONF=$bingetconf"
 got=$(getconf -n GETCONF)
 [[ $exp == "$got" ]] || err_exit "'getconf -n' doesn't match names correctly" \
-	"(expected $exp, got $got)"
+	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
 
 # ======
 # Test shell builtin commands
@@ -1201,12 +1201,12 @@ exp=$(uname -o)
 
 # Test for a possible crash (to avoid crashing the script, fork the subshell)
 (
-	ulimit -t unlimited
+	ulimit -t unlimited 2> /dev/null
 	uname -d > /dev/null
 ) || err_exit "'uname -d' crashes"
 
 # 'uname -d' shouldn't change the output of 'uname -o'
-got=$(ulimit -t unlimited; uname -d > /dev/null; uname -o)
+got=$(ulimit -t unlimited 2> /dev/null; uname -d > /dev/null; uname -o)
 [[ $exp == $got ]] || err_exit "'uname -d' changes the output of 'uname -o'" \
 	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
 

src/cmd/ksh93/tests/functions.sh

@@ -31,9 +31,25 @@ bin_echo=$(whence -p echo)
 bin_sleep=$(whence -p sleep)
 bin_kill=$(whence -p kill)
 
+# ======
+# In ksh93v- and ksh2020 eval'ing a function definition may dump the function body to stdout.
+# https://github.com/att/ast/issues/1160
+got="$($SHELL -c '
+	for ((i=0; i<1025; i++))
+	do	str="${str}12345678"
+	done
+	eval "foo() { $str; }"
+
+	baz() { eval "bar() { FAILURE; }"; }
+	( baz >&3 ) 3>&1
+')"
+[[ -n "$got" ]] && err_exit "eval'ing function dumps function body to stdout" \
+	"(got $(printf %q "$got"))"
+
+# ======
+# Check for global variables and $0
 integer foo=33
 bar=bye
-# check for global variables and $0
 function foobar
 {
 	case $1 in

src/cmd/ksh93/tests/io.sh

@@ -283,12 +283,22 @@ EOF) == 'hello world' ]] || err_exit 'invalid readahead on stdin'
 $SHELL -c 'exec 3>; /dev/null'  2> /dev/null && err_exit '>; with exec should be an error'
 $SHELL -c ': 3>; /dev/null'  2> /dev/null || err_exit '>; not working with at all'
 print hello > $tmp/1
-if	! $SHELL -c "false >; $tmp/1"  2> /dev/null
-then	let 1;[[ $(<$tmp/1) == hello ]] || err_exit '>; not preserving file on failure'
-fi
-if	! $SHELL -c "sed -e 's/hello/hello world/' $tmp/1" >; $tmp/1  2> /dev/null
-then	[[ $(<$tmp/1) == 'hello world' ]] || err_exit '>; not updating file on success'
-fi
+$SHELL -c "false >; $tmp/1"
+status=$?
+(( status == 1 )) || err_exit "unexpected exit status" \
+	"(expected 1, got $status)"
+exp='hello'
+got=$(<$tmp/1)
+[[ $got == "$exp" ]] || err_exit '>; not preserving file on failure' \
+	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
+$SHELL -c "sed -e 's/hello/hello world/' $tmp/1" >; $tmp/1
+status=$?
+(( status == 0 )) || err_exit "unexpected exit status" \
+	"(expected 0, got $status)"
+exp='hello world'
+got="$(<$tmp/1)"
+[[ $got == "$exp" ]] || err_exit '>; not updating file on success' \
+	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
 
 $SHELL -c 'exec 3<>; /dev/null'  2> /dev/null && err_exit '<>; with exec should be an error'
 $SHELL -c ': 3<>; /dev/null'  2> /dev/null || err_exit '<>; not working with at all'
@@ -474,13 +484,6 @@ do      out=$("$binfalse" 2>/dev/null)
 	fi
 done
 
-rm -f $tmp/file1 $tmp/file2
-print foo > $tmp/file3
-ln -s $tmp/file3 $tmp/file2
-ln -s $tmp/file2 $tmp/file1
-print bar >; $tmp/file1
-[[ $(<$tmp/file3) == bar ]] || err_exit '>; not following symlinks'
-
 for i in 1
 do	:
 done	{n}< /dev/null
@@ -639,8 +642,8 @@ fi
 
 # ======
 # "&>file" redirection operator, shorthand for ">file 2>&1" (new as of 93u+m; inherited from old SHOPT_BASH)
-if	[[ -o ?posix ]]
-then	set -o posix
+if	[[ -o ?posix ]] && command set -o posix
+then
 	# This should print in a background job, then create an empty file, as '>aha1.txt' is a separate command.
 	eval '	print -u1 bad1 &>aha1.txt
 		print -u2 bad2 &>aha2.txt
@@ -654,11 +657,8 @@ then	set -o posix
 	' >/dev/null 2>&1
 	[[ $(< aha1.txt) == ok1 ]] || err_exit '&> does not redirect stdout'
 	[[ $(< aha2.txt) == ok2 ]] || err_exit '&> does not redirect stderr'
-fi
-
-# In POSIX mode, file descriptors > 2 should remain open when invoking another program
-if	[[ -o ?posix ]]
-then	(set -o posix; exec 7>ok.txt; "$SHELL" -c 'print ok >&7' 2>/dev/null)
+	# In POSIX mode, file descriptors > 2 should remain open when invoking another program
+	(set -o posix; exec 7>ok.txt; "$SHELL" -c 'print ok >&7' 2>/dev/null)
 	[[ $(<ok.txt) == ok ]] || err_exit 'File descriptors > 2 not inherited in POSIX mode'
 fi
 (exec 7>bad.txt; "$SHELL" -c 'print bad >&7' 2>/dev/null)
@@ -853,5 +853,30 @@ cat >out2 < <(case x in x) cat out1;; esac)
 [[ $(<out2) == ok ]] || err_exit "process substitution not working as file name to redirection" \
 	"(expected 'ok', got $(printf %q "$(<out2)"))"
 
+# ======
+# Reading a file through a command substitution
+# https://github.com/att/ast/issues/203
+TMPF=$tmp/tmpf
+echo foo >$TMPF
+export TMPF
+[[ -n "$($SHELL -c 'echo $(<$TMPF)' <&-)" ]] || err_exit "Closing stdin causes failure when reading file through \$(<)"
+[[ -n "$($SHELL -c "$SHELL -c 'echo \$(<$TMPF) >&2' >&-" 2>&1)" ]] || err_exit "Closing stdout causes failure when reading file through \$(<)"
+[[ -n "$($SHELL -c 'echo $(<$TMPF)' 2>&-)" ]]  || err_exit "Closing stderr causes failure when reading file through \$(<)"
+
+# ======
+# Verify that symlinks are correctly canonicalized as part of a conditional redirection.
+# https://github.com/att/ast/issues/492
+mkdir -p dir1/dir2
+ln -s dir1 s1
+cd dir1
+ln -s dir2 s2
+cd ..
+exp=symlinks-resolved
+print wrong-answer > dir1/dir2/x
+print $exp >; s1/s2/x
+got=$(< dir1/dir2/x)
+[[ $got == "$exp" ]] || err_exit "symlink in conditional redirect wrong" \
+	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
+
 # ======
 exit $((Errors<125?Errors:125))

src/cmd/ksh93/tests/pty.sh

@@ -577,6 +577,10 @@ actual=$(echo begin; exec >/dev/tty; [ -t ] && test -t) \
 && echo OK7 || echo 'test -t in comsub with exec >/dev/tty fails'
 actual=$(echo begin; exec >/dev/tty; [ -n X -a -t ] && test -n X -a -t) \
 && echo OK8 || echo 'test -t in comsub with exec >/dev/tty fails (compound expression)'
+# The broken ksh2020 fix for [ -t 1 ] (https://github.com/att/ast/pull/1083) caused
+# [ -t 1 ] to fail in non-comsub virtual subshells.
+( test -t 1 ) && echo OK9 || echo 'test -t 1 in virtual subshell fails'
+( test -t ) && echo OK10 || echo 'test -t in virtual subshell fails'
 EOF
 tst $LINENO <<"!"
 L test -t 1 inside command substitution
@@ -593,6 +597,8 @@ r ^OK5\r\n$
 r ^OK6\r\n$
 r ^OK7\r\n$
 r ^OK8\r\n$
+r ^OK9\r\n$
+r ^OK10\r\n$
 r ^:test-2:
 !
 
@@ -841,5 +847,16 @@ r \t#foo\r\n$
 r \thist -lnN 1\r\n$
 !
 
+# err_exit #
+((SHOPT_VSH || SHOPT_ESH)) && tst $LINENO <<"!"
+L tab completion while expanding ${.sh.*} variables
+# https://github.com/att/ast/issues/1461
+
+d 15
+p :test-1:
+w test \$\{.sh.level\t
+r ^:test-1: test \$\{.sh.level\}\r\n$
+!
+
 # ======
 exit $((Errors<125?Errors:125))

src/cmd/ksh93/tests/shtests

@@ -446,7 +446,7 @@ print "Total errors: $total_e"
 # if we have the 'times' builtin and can use process substitution with output redirection.
 # See:	https://github.com/ksh93/ksh/commit/65d363fd
 #	https://github.com/ksh93/ksh/issues/2
-if 	(	ulimit -t unlimited	# fork to circumvent old ksh bugs
+if 	(	ulimit -t unlimited 2> /dev/null  # fork to circumvent old ksh bugs
 		unalias times
 		PATH=/dev/null whence -q times || exit
 		cd "$tmp" || exit

src/cmd/ksh93/tests/variables.sh

@@ -1344,5 +1344,14 @@ exp=5
 got=$($SHELL "$lineno_subshell")
 [[ $exp == $got ]] || err_exit "LINENO corrupted after leaving virtual subshell (expected $exp, got $got)"
 
+# ======
+# Check if ${.sh.file} is set to correct value after sourcing a file
+# https://github.com/att/ast/issues/472
+cat > $tmp/foo.sh <<EOF
+echo "foo"
+EOF
+. $tmp/foo.sh > /dev/null
+[[ ${.sh.file} == $0 ]] || err_exit "\${.sh.file} is not set to the correct value after sourcing a file"
+
 # ======
 exit $((Errors<125?Errors:125))