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fixes #546 terminfo tput escape sequence errors
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These fix errors discovered while implementing the same logic
in dcell.  While here, the conditional support was simplified
using a similar approach as used in dcell, and test cases were
added.
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@gdamore
gdamore committed Aug 31, 2022
1 parent 46afc52 commit c389caa
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Showing 2 changed files with 109 additions and 115 deletions.
173 changes: 58 additions & 115 deletions terminfo/terminfo.go
View file
Expand Up @@ -240,15 +240,14 @@ const (
type stack []interface{}

func (st stack) Push(v interface{}) stack {
return append(st, v)
}

func (st stack) Pop() (interface{}, stack) {
if len(st) > 0 {
e := st[len(st)-1]
return e, st[:len(st)-1]
if b, ok := v.(bool); ok {
if b {
return append(st, 1)
} else {
return append(st, 0)
}
}
return 0, st
return append(st, v)
}

func (st stack) PopString() (string, stack) {
Expand All @@ -258,8 +257,6 @@ func (st stack) PopString() (string, stack) {
switch v := e.(type) {
case int:
s = strconv.Itoa(v)
case bool:
s = strconv.FormatBool(v)
case string:
s = v
}
Expand All @@ -275,12 +272,6 @@ func (st stack) PopInt() (int, stack) {
switch v := e.(type) {
case int:
i = v
case bool:
if v {
i = 1
} else {
i = 0
}
case string:
i, _ = strconv.Atoi(v)
}
Expand All @@ -289,42 +280,18 @@ func (st stack) PopInt() (int, stack) {
return 0, st
}

func (st stack) PopBool() (bool, stack) {
var b bool
if len(st) > 0 {
e := st[len(st)-1]
switch v := e.(type) {
case int:
b = v != 0
case bool:
b = v
case string:
b = v != "" && v != "false"
}
return b, st[:len(st)-1]
}
return false, st
}

// static vars
var svars [26]string

// paramsBuffer handles some persistent state for TParam. Technically we
// could probably dispense with this, but caching buffer arrays gives us
// a nice little performance boost. Furthermore, we know that TParam is
// rarely (never?) called re-entrantly, so we can just reuse the same
// buffers, making it thread-safe by stashing a lock.
type paramsBuffer struct {
out bytes.Buffer
buf bytes.Buffer
lk sync.Mutex
}

// Start initializes the params buffer with the initial string data.
// It also locks the paramsBuffer. The caller must call End() when
// finished.
func (pb *paramsBuffer) Start(s string) {
pb.lk.Lock()
pb.out.Reset()
pb.buf.Reset()
pb.buf.WriteString(s)
Expand All @@ -333,7 +300,6 @@ func (pb *paramsBuffer) Start(s string) {
// End returns the final output from TParam, but it also releases the lock.
func (pb *paramsBuffer) End() string {
s := pb.out.String()
pb.lk.Unlock()
return s
}

Expand All @@ -352,18 +318,16 @@ func (pb *paramsBuffer) PutString(s string) {
pb.out.WriteString(s)
}

var pb = &paramsBuffer{}

// TParm takes a terminfo parameterized string, such as setaf or cup, and
// evaluates the string, and returns the result with the parameter
// applied.
func (t *Terminfo) TParm(s string, p ...interface{}) string {
var stk stack
var a, b string
var a string
var ai, bi int
var ab bool
var dvars [26]string
var params [9]interface{}
var pb = &paramsBuffer{}

pb.Start(s)

Expand All @@ -373,7 +337,13 @@ func (t *Terminfo) TParm(s string, p ...interface{}) string {
params[i] = p[i]
}

nest := 0
const (
emit = iota
toEnd
toElse
)

skip := emit

for {

Expand All @@ -383,7 +353,9 @@ func (t *Terminfo) TParm(s string, p ...interface{}) string {
}

if ch != '%' {
pb.PutCh(ch)
if skip == emit {
pb.PutCh(ch)
}
continue
}

Expand All @@ -392,6 +364,17 @@ func (t *Terminfo) TParm(s string, p ...interface{}) string {
// XXX Error
break
}
if skip == toEnd {
if ch == ';' {
skip = emit
}
continue
} else if skip == toElse {
if ch == 'e' || ch == ';' {
skip = emit
}
continue
}

switch ch {
case '%': // quoted %
Expand All @@ -405,18 +388,23 @@ func (t *Terminfo) TParm(s string, p ...interface{}) string {
params[1] = i + 1
}

case 'c', 's':
// NB: these, and 'd' below are special cased for
case 's':
// NB: 's', 'c', and 'd' below are special cased for
// efficiency. They could be handled by the richer
// format support below, less efficiently.
a, stk = stk.PopString()
pb.PutString(a)

case 'c':
// Integer as special character.
ai, stk = stk.PopInt()
pb.PutCh(byte(ai))

case 'd':
ai, stk = stk.PopInt()
pb.PutString(strconv.Itoa(ai))

case '0', '1', '2', '3', '4', 'x', 'X', 'o', ':':
case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'x', 'X', 'o', ':':
// This is pretty suboptimal, but this is rarely used.
// None of the mainstream terminals use any of this,
// and it would surprise me if this code is ever
Expand All @@ -438,9 +426,12 @@ func (t *Terminfo) TParm(s string, p ...interface{}) string {
case 'd', 'x', 'X', 'o':
ai, stk = stk.PopInt()
pb.PutString(fmt.Sprintf(f, ai))
case 'c', 's':
case 's':
a, stk = stk.PopString()
pb.PutString(fmt.Sprintf(f, a))
case 'c':
ai, stk = stk.PopInt()
pb.PutString(fmt.Sprintf(f, ai))
}

case 'p': // push parameter
Expand Down Expand Up @@ -468,10 +459,10 @@ func (t *Terminfo) TParm(s string, p ...interface{}) string {
stk = stk.Push(dvars[int(ch-'a')])
}

case '\'': // push(char)
case '\'': // push(char) - the integer value of it
ch, _ = pb.NextCh()
_, _ = pb.NextCh() // must be ' but we don't check
stk = stk.Push(string(ch))
stk = stk.Push(int(ch))

case '{': // push(int)
ai = 0
Expand Down Expand Up @@ -542,12 +533,12 @@ func (t *Terminfo) TParm(s string, p ...interface{}) string {

case '!': // logical NOT
ai, stk = stk.PopInt()
stk = stk.Push(ai != 0)
stk = stk.Push(ai == 0)

case '=': // numeric compare or string compare
b, stk = stk.PopString()
a, stk = stk.PopString()
stk = stk.Push(a == b)
case '=': // numeric compare
bi, stk = stk.PopInt()
ai, stk = stk.PopInt()
stk = stk.Push(ai == bi)

case '>': // greater than, numeric
bi, stk = stk.PopInt()
Expand All @@ -561,68 +552,20 @@ func (t *Terminfo) TParm(s string, p ...interface{}) string {

case '?': // start conditional

case ';':
skip = emit

case 't':
ab, stk = stk.PopBool()
if ab {
// just keep going
break
}
nest = 0
ifloop:
// this loop consumes everything until we hit our else,
// or the end of the conditional
for {
ch, err = pb.NextCh()
if err != nil {
break
}
if ch != '%' {
continue
}
ch, _ = pb.NextCh()
switch ch {
case ';':
if nest == 0 {
break ifloop
}
nest--
case '?':
nest++
case 'e':
if nest == 0 {
break ifloop
}
}
ai, stk = stk.PopInt()
if ai == 0 {
skip = toElse
}

case 'e':
// if we got here, it means we didn't use the else
// in the 't' case above, and we should skip until
// the end of the conditional
nest = 0
elloop:
for {
ch, err = pb.NextCh()
if err != nil {
break
}
if ch != '%' {
continue
}
ch, _ = pb.NextCh()
switch ch {
case ';':
if nest == 0 {
break elloop
}
nest--
case '?':
nest++
}
}

case ';': // endif
skip = toEnd

default:
pb.PutString("%" + string(ch))
}
}

Expand Down
51 changes: 51 additions & 0 deletions terminfo/terminfo_test.go
View file
Expand Up @@ -63,6 +63,57 @@ func TestTerminfoExpansion(t *testing.T) {
if ti.TParm(ti.SetFg, 200) != "\x1b[38;5;200m" {
t.Error("SetFg(200) failed")
}

type testCase struct {
expect string
format string
params []interface{}
}

cases := []testCase{
{expect: "0a", format: "%p1%02x", params: []interface{}{10}},
{expect: "0A", format: "%p1%02X", params: []interface{}{10}},
{expect: "A", format: "%p1%c", params: []interface{}{65}},
{expect: "A", format: "%'A'%c", params: []interface{}{}},
{expect: "65", format: "%'A'%d", params: []interface{}{}},
{expect: "7", format: "%i%p1%p2%+%d", params: []interface{}{2, 3}},
{expect: "abc", format: "%p1%s", params: []interface{}{"abc"}},
{expect: "1%d", format: "1%%d", params: []interface{}{}},
{expect: "abc", format: "%p1%s%", params: []interface{}{"abc"}}, // unterminated %
{expect: " abc", format: "%p1%5s", params: []interface{}{"abc"}},
{expect: "abc ", format: "%p1%:-5s", params: []interface{}{"abc"}},
{expect: "15", format: "%{3}%p1%*%d", params: []interface{}{5}},
{expect: " A", format: "%p1%2c", params: []interface{}{65}},
{expect: "4", format: "%p1%l%d", params: []interface{}{"four"}},
{expect: "0", format: "%pA%d", params: []interface{}{}}, // missing/invalid parameter
{expect: "5", format: "%p1%p2%/%d", params: []interface{}{15, 3}},
{expect: "0", format: "%p1%p2%/%d", params: []interface{}{3, 15}},
{expect: "0", format: "%p1%p2%/%d", params: []interface{}{3, 0}},
{expect: "3", format: "%p1%p2%m%d", params: []interface{}{15, 4}},
{expect: "0", format: "%p1%p2%m%d", params: []interface{}{3, 0}},
{expect: "2", format: "%p1%Pa%{4}%{3}%ga%d", params: []interface{}{2}},
{expect: "2", format: "%p1%PA%{4}%{3}%gA%d", params: []interface{}{2}},
{expect: "0", format: "%p1%PA%{4}%{3}%ga%d", params: []interface{}{2}},
{expect: "0", format: "%p1%Pz%{4}%{3}%gZ%d", params: []interface{}{2}},
{expect: "0", format: "%d", params: []interface{}{}}, // underflow
{expect: "", format: "%s", params: []interface{}{}}, // underflow
{expect: "1", format: "%p1%p2%=%d", params: []interface{}{3, 3}},
{expect: "0", format: "%p1%p2%=%d", params: []interface{}{3, 4}},
{expect: "1", format: "%p1%p2%=%!%d", params: []interface{}{3, 4}},
{expect: "1", format: "%p1%p2%>%d", params: []interface{}{4, 3}},
{expect: "3", format: "%p1%p2%|%d", params: []interface{}{1, 2}},
{expect: "2", format: "%p1%p2%&%d", params: []interface{}{2, 3}},
{expect: "1", format: "%p1%p2%^%d", params: []interface{}{2, 3}},
{expect: "f", format: "%p1%~%{255}%&%x", params: []interface{}{0xf0}},
{expect: "%Z", format: "%Z", params: []interface{}{2, 3}}, // unknown sequence
}

for i := range cases {
if res := ti.TParm(cases[i].format, cases[i].params...); res != cases[i].expect {
t.Errorf("Format case %d failed: Format %q got %q", i, cases[i].format, res)
}
}
t.Logf("Tested %d cases", len(cases))
}

func TestTerminfoDelay(t *testing.T) {
Expand Down

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