[css-grid] Fix grid placement with '<integer> && <custom-ident>'

The logic for placing a grid item with both an integer and an identifier
in a placement property was interacting wrong with auto repeat() tracks.

This patch uses the same proper logic that was already implemented in
OrderedNamedLinesCollectorInGridLayout::CollectLineNamesForIndex

BUG=966090

TEST=external/wpt/css/css-grid/placement/grid-placement-using-named-grid-lines-004.html

Change-Id: I042ce1fd77a79959240d272d96eac21f06e014ac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2082917Reviewed-by: Javier Fernandez <jfernandez@igalia.com>
Commit-Queue: Oriol Brufau <obrufau@igalia.com>
Cr-Commit-Position: refs/heads/master@{#747631}

third_party/blink/renderer/core/style/grid_positions_resolver.cc

@@ -63,44 +63,42 @@ bool NamedLineCollection::HasNamedLines() {
   return named_lines_indexes_ || auto_repeat_named_lines_indexes_;
 }
 
-size_t NamedLineCollection::Find(size_t line) {
+bool NamedLineCollection::Contains(size_t line) {
+  CHECK(HasNamedLines());
+
   if (line > last_line_)
-    return kNotFound;
-
-  if (!auto_repeat_named_lines_indexes_ || line < insertion_point_)
-    return named_lines_indexes_ ? named_lines_indexes_->Find(line) : kNotFound;
-
-  if (line <= (insertion_point_ + auto_repeat_total_tracks_)) {
-    size_t local_index = line - insertion_point_;
-
-    size_t index_in_first_repetition =
-        local_index % auto_repeat_track_list_length_;
-    if (index_in_first_repetition)
-      return auto_repeat_named_lines_indexes_->Find(index_in_first_repetition);
-
-    // The line names defined in the last line are also present in the first
-    // line of the next repetition (if any). Same for the line names defined in
-    // the first line.
-    if (local_index == auto_repeat_total_tracks_)
-      return auto_repeat_named_lines_indexes_->Find(
-          auto_repeat_track_list_length_);
-    size_t position =
-        auto_repeat_named_lines_indexes_->Find(static_cast<size_t>(0));
-    if (position != kNotFound)
-      return position;
-    return local_index == 0 ? kNotFound
-                            : auto_repeat_named_lines_indexes_->Find(
-                                  auto_repeat_track_list_length_);
+    return false;
+
+  auto find = [](const Vector<size_t>* indexes, size_t line) {
+    return indexes && indexes->Find(line) != kNotFound;
+  };
+
+  if (auto_repeat_track_list_length_ == 0LU || line < insertion_point_)
+    return find(named_lines_indexes_, line);
+
+  DCHECK(auto_repeat_total_tracks_);
+
+  if (line > insertion_point_ + auto_repeat_total_tracks_)
+    return find(named_lines_indexes_, line - (auto_repeat_total_tracks_ - 1));
+
+  if (line == insertion_point_) {
+    return find(named_lines_indexes_, line) ||
+           find(auto_repeat_named_lines_indexes_, 0);
   }
 
-  return named_lines_indexes_ ? named_lines_indexes_->Find(
-                                    line - (auto_repeat_total_tracks_ - 1))
-                              : kNotFound;
-}
+  if (line == insertion_point_ + auto_repeat_total_tracks_) {
+    return find(auto_repeat_named_lines_indexes_,
+                auto_repeat_track_list_length_) ||
+           find(named_lines_indexes_, insertion_point_ + 1);
+  }
 
-bool NamedLineCollection::Contains(size_t line) {
-  CHECK(HasNamedLines());
-  return Find(line) != kNotFound;
+  size_t auto_repeat_index_in_first_repetition =
+      (line - insertion_point_) % auto_repeat_track_list_length_;
+  if (!auto_repeat_index_in_first_repetition &&
+      find(auto_repeat_named_lines_indexes_, auto_repeat_track_list_length_))
+    return true;
+  return find(auto_repeat_named_lines_indexes_,
+              auto_repeat_index_in_first_repetition);
 }
 
 size_t NamedLineCollection::FirstPosition() {

third_party/blink/renderer/core/style/grid_positions_resolver.h

@@ -38,7 +38,6 @@ class NamedLineCollection {
   bool Contains(size_t line);
 
  private:
-  size_t Find(size_t line);
   const Vector<size_t>* named_lines_indexes_ = nullptr;
   const Vector<size_t>* auto_repeat_named_lines_indexes_ = nullptr;
 

third_party/blink/web_tests/external/wpt/css/css-grid/placement/grid-placement-using-named-grid-lines-004.html

+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Grid Layout Test: Grid item placement with '&lt;integer&gt; && &lt;custom-ident&gt;' and auto repeat()</title>
+<link rel="author" title="Oriol Brufau" href="mailto:obrufau@igalia.com">
+<link rel="help" href="http://www.w3.org/TR/css-grid-1/#line-placement">
+<link rel="match" href="../../reference/ref-filled-green-100px-square.xht">
+<meta name="assert" content="Grid placement algorithm is able to select the right line when using the '<integer> && <custom-ident>' syntax and there is an auto repeat().">
+<style>
+.grid {
+  display: grid;
+  width: 300px;
+  height: 300px;
+  grid-template-columns: [foo] repeat(auto-fill, 100px [foo]);
+  grid-template-rows: repeat(auto-fill, [foo] 100px);
+}
+.grid > div {
+  grid-area: 1 foo / 1 foo;
+  background: green;
+}
+</style>
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div class="grid">
+  <div></div>
+</div>