Skip to content

Prevent stack overflow from cyclic key references #410

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
rupayon123 wants to merge 1 commit into
base: main
Choose a base branch
from
Open

Prevent stack overflow from cyclic key references #410

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
15 changes: 14 additions & 1 deletion key.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -140,6 +140,10 @@ func (k *Key) NestedValues() []string {

// transformValue takes a raw value and transforms to its final string.
func (k *Key) transformValue(val string) string {
return k.transformValueWithVisited(val, map[*Key]bool{k: true})
}

func (k *Key) transformValueWithVisited(val string, visited map[*Key]bool) string {
if k.s.f.ValueMapper != nil {
val = k.s.f.ValueMapper(val)
}
Expand Down Expand Up @@ -169,8 +173,17 @@ func (k *Key) transformValue(val string) string {
}
}

// A reference back to a key already being resolved is left intact,
// just like a direct self-reference.
if visited[nk] {
break
}
visited[nk] = true
replacement := nk.transformValueWithVisited(nk.value, visited)
delete(visited, nk)

// Substitute by new value and take off leading '%(' and trailing ')s'.
val = strings.ReplaceAll(val, vr, nk.String())
val = strings.ReplaceAll(val, vr, replacement)
}
return val
}
Expand Down
13 changes: 13 additions & 0 deletions key_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -626,6 +626,19 @@ expires = %(expires)s`))
assert.Equal(t, "yes", f.Section("package").Key("expires").String())
})

t.Run("mutually recursive keys remain unresolved", func(t *testing.T) {
f, err := Load([]byte("[s]\na = %(b)s\nb = %(a)s\n"))
require.NoError(t, err)
assert.Equal(t, "%(a)s", f.Section("s").Key("a").String())
assert.Equal(t, "%(b)s", f.Section("s").Key("b").String())
})

t.Run("longer reference cycle remains unresolved", func(t *testing.T) {
f, err := Load([]byte("[s]\na = %(b)s\nb = %(c)s\nc = %(a)s\n"))
require.NoError(t, err)
assert.Equal(t, "%(a)s", f.Section("s").Key("a").String())
})

t.Run("recursive value with no target found", func(t *testing.T) {
f, err := Load([]byte(`
[foo]
Expand Down