diff options
Diffstat (limited to 'Userland/Libraries')
| -rw-r--r-- | Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp | 33 |
1 files changed, 19 insertions, 14 deletions
diff --git a/Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp b/Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp index 52b4965ab9..14f4776149 100644 --- a/Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp +++ b/Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp @@ -179,13 +179,21 @@ static inline bool matches_pseudo_class(CSS::Selector::SimpleSelector::PseudoCla VERIFY_NOT_REACHED(); } - if (step_size < 0) { - // When "step_size" is negative, selector represents first "offset" elements in document tree. + // When "step_size == -1", selector represents first "offset" elements in document tree. + if (step_size == -1) return !(offset <= 0 || index > offset); - } else if (step_size == 1) { - // When "step_size == 1", selector represents last "offset" elements in document tree. + + // When "step_size == 1", selector represents last "offset" elements in document tree. + if (step_size == 1) return !(offset < 0 || index < offset); - } + + // When "step_size == 0", selector picks only the "offset" element. + if (step_size == 0) + return index == offset; + + // If both are negative, nothing can match. + if (step_size < 0 && offset < 0) + return false; // Like "a % b", but handles negative integers correctly. auto const canonical_modulo = [](int a, int b) -> int { @@ -196,15 +204,12 @@ static inline bool matches_pseudo_class(CSS::Selector::SimpleSelector::PseudoCla return c; }; - if (step_size == 0) { - // Avoid divide by zero. - if (index != offset) { - return false; - } - } else if (canonical_modulo(index - offset, step_size) != 0) { - return false; - } - return true; + // When "step_size < 0", we start at "offset" and count backwards. + if (step_size < 0) + return index <= offset && canonical_modulo(index - offset, -step_size) == 0; + + // Otherwise, we start at "offset" and count forwards. + return index >= offset && canonical_modulo(index - offset, step_size) == 0; } return false; |