LibWeb: Rerun find in page query when navigating between URLs

Previously, the "Find Next Match" and "Find Previous Match" actions
simply updated the match index of the last query to be performed. This
led to incorrect results if the page had been modified after the last
query had been run.

`Page::find_in_page_next_match()` and
`Page::find_in_page_previous_match()` both now rerun the last query to
ensure the results are up to date before updating the match index.

The match index is also reset if the URL of the active document has
changed since the last query. The current match index is maintained if
only the URL fragment changes.

Userland/Libraries/LibWeb/Page/Page.cpp

@@ -563,26 +563,29 @@ void Page::clear_selection()
     }
 }
 
-Page::FindInPageResult Page::find_in_page(String const& query, CaseSensitivity case_sensitivity)
+Page::FindInPageResult Page::perform_find_in_page_query(FindInPageQuery const& query)
 {
-    m_find_in_page_match_index = 0;
-
-    if (query.is_empty()) {
-        m_find_in_page_matches = {};
-        update_find_in_page_selection();
-        return {};
-    }
+    VERIFY(top_level_traversable_is_initialized());
 
     Vector<JS::Handle<DOM::Range>> all_matches;
     for (auto const& document : documents_in_active_window()) {
-        auto matches = document->find_matching_text(query, case_sensitivity);
+        auto matches = document->find_matching_text(query.string, query.case_sensitivity);
         all_matches.extend(move(matches));
     }
 
     m_find_in_page_matches.clear_with_capacity();
     for (auto& match : all_matches)
         m_find_in_page_matches.append(*match);
 
+    if (auto active_document = top_level_traversable()->active_document()) {
+        if (m_last_find_in_page_url.serialize(URL::ExcludeFragment::Yes) != active_document->url().serialize(URL::ExcludeFragment::Yes)) {
+            m_last_find_in_page_url = top_level_traversable()->active_document()->url();
+            m_find_in_page_match_index = 0;
+        }
+    } else if (m_find_in_page_match_index >= m_find_in_page_matches.size()) {
+        m_find_in_page_match_index = 0;
+    }
+
     update_find_in_page_selection();
 
     return Page::FindInPageResult {
@@ -591,42 +594,52 @@ Page::FindInPageResult Page::find_in_page(String const& query, CaseSensitivity c
     };
 }
 
+Page::FindInPageResult Page::find_in_page(FindInPageQuery const& query)
+{
+    if (!top_level_traversable_is_initialized())
+        return {};
+
+    m_find_in_page_match_index = 0;
+    m_last_find_in_page_query = query;
+    m_last_find_in_page_url = top_level_traversable()->active_document()->url();
+
+    if (query.string.is_empty()) {
+        m_last_find_in_page_query = {};
+        update_find_in_page_selection();
+        return {};
+    }
+
+    return perform_find_in_page_query(query);
+}
+
 Page::FindInPageResult Page::find_in_page_next_match()
 {
-    if (m_find_in_page_matches.is_empty())
+    if (!(m_last_find_in_page_query.has_value() && top_level_traversable_is_initialized()))
         return {};
 
-    if (m_find_in_page_match_index == m_find_in_page_matches.size() - 1) {
+    auto result = perform_find_in_page_query(*m_last_find_in_page_query);
+    if (m_find_in_page_match_index == *result.total_match_count - 1) {
         m_find_in_page_match_index = 0;
     } else {
         m_find_in_page_match_index++;
     }
 
-    update_find_in_page_selection();
-
-    return Page::FindInPageResult {
-        .current_match_index = m_find_in_page_match_index,
-        .total_match_count = m_find_in_page_matches.size(),
-    };
+    return result;
 }
 
 Page::FindInPageResult Page::find_in_page_previous_match()
 {
-    if (m_find_in_page_matches.is_empty())
+    if (!(m_last_find_in_page_query.has_value() && top_level_traversable_is_initialized()))
         return {};
 
+    auto result = perform_find_in_page_query(*m_last_find_in_page_query);
     if (m_find_in_page_match_index == 0) {
-        m_find_in_page_match_index = m_find_in_page_matches.size() - 1;
+        m_find_in_page_match_index = *result.total_match_count - 1;
     } else {
         m_find_in_page_match_index--;
     }
 
-    update_find_in_page_selection();
-
-    return Page::FindInPageResult {
-        .current_match_index = m_find_in_page_match_index,
-        .total_match_count = m_find_in_page_matches.size(),
-    };
+    return result;
 }
 
 void Page::update_find_in_page_selection()

Userland/Libraries/LibWeb/Page/Page.h

@@ -187,11 +187,15 @@ class Page final : public JS::Cell {
 
     void clear_selection();
 
+    struct FindInPageQuery {
+        String string {};
+        CaseSensitivity case_sensitivity { CaseSensitivity::CaseInsensitive };
+    };
     struct FindInPageResult {
         size_t current_match_index { 0 };
         Optional<size_t> total_match_count {};
     };
-    FindInPageResult find_in_page(String const& query, CaseSensitivity);
+    FindInPageResult find_in_page(FindInPageQuery const&);
     FindInPageResult find_in_page_next_match();
     FindInPageResult find_in_page_previous_match();
 
@@ -203,6 +207,7 @@ class Page final : public JS::Cell {
 
     Vector<JS::Handle<DOM::Document>> documents_in_active_window() const;
 
+    FindInPageResult perform_find_in_page_query(FindInPageQuery const&);
     void update_find_in_page_selection();
 
     JS::NonnullGCPtr<PageClient> m_client;
@@ -248,6 +253,8 @@ class Page final : public JS::Cell {
     bool m_pdf_viewer_supported { false };
     size_t m_find_in_page_match_index { 0 };
     Vector<JS::NonnullGCPtr<DOM::Range>> m_find_in_page_matches;
+    Optional<FindInPageQuery> m_last_find_in_page_query;
+    URL::URL m_last_find_in_page_url;
 };
 
 struct PaintOptions {

Userland/Services/WebContent/ConnectionFromClient.cpp

@@ -812,7 +812,7 @@ void ConnectionFromClient::find_in_page(u64 page_id, String const& query, CaseSe
     if (!page.has_value())
         return;
 
-    auto result = page->page().find_in_page(query, case_sensitivity);
+    auto result = page->page().find_in_page({ .string = query, .case_sensitivity = case_sensitivity });
     async_did_find_in_page(page_id, result.current_match_index, result.total_match_count);
 }