func urlUnescape(s string, doPlus bool) (string, error) {
// Count %, check that they're well-formed.
n := 0
hasPlus := false
for i := 0; i < len(s); {
switch s[i] {
case '%':
n++
if i+2 >= len(s) || !ishex(s[i+1]) || !ishex(s[i+2]) {
s = s[i:]
if len(s) > 3 {
s = s[0:3]
}
return "", url.EscapeError(s)
}
i += 3
case '+':
hasPlus = doPlus
i++
default:
i++
}
}
if n == 0 && !hasPlus {
return s, nil
}
t := make([]byte, len(s)-2*n)
j := 0
for i := 0; i < len(s); {
switch s[i] {
case '%':
t[j] = unhex(s[i+1])<<4 | unhex(s[i+2])
j++
i += 3
case '+':
if doPlus {
t[j] = ' '
} else {
t[j] = '+'
}
j++
i++
default:
t[j] = s[i]
j++
i++
}
}
return string(t), nil
}
func pathUnescape(s string) (string, error) {
// Count %, check that they're well-formed.
n := 0
for i := 0; i < len(s); {
switch s[i] {
case '%':
n++
if i+2 >= len(s) || !ishex(s[i+1]) || !ishex(s[i+2]) {
s = s[i:]
if len(s) > 3 {
s = s[0:3]
}
return "", url.EscapeError(s)
}
i += 3
case '+':
i++
default:
i++
}
}
if n == 0 {
return s, nil
}
t := make([]byte, len(s)-2*n)
j := 0
for i := 0; i < len(s); {
switch s[i] {
case '%':
t[j] = unhex(s[i+1])<<4 | unhex(s[i+2])
j++
i += 3
default:
t[j] = s[i]
j++
i++
}
}
return string(t), nil
}
t.Errorf("ishex(%v) == %v, expected %v", test.input, actual, test.ishex)
}
if actual := unhex(test.input); actual != test.unhex {
t.Errorf("unhex(%v) == %v, expected %v", test.input, actual, test.unhex)
}
}
}
var UnescapeTests = []struct {
input string
err error
output string
}{
{"hello", nil, "hello"},
{"file%20one%26two", nil, "file one&two"},
{"one/two%2fthree", nil, "one/two/three"},
{"this%20is%0not%valid", url.EscapeError("%0n"), ""},
}
func TestUnescape(t *testing.T) {
t.Parallel()
for _, test := range UnescapeTests {
if actual, err := unescape(test.input); err != test.err {
t.Errorf("unescape(%q) had err %v, expected %q", test.input, err, test.err)
} else if actual != test.output {
t.Errorf("unescape(%q) = %q, expected %q)", test.input, actual, test.output)
}
}
}