Named pages should only have an effect when paginated.

Need to check if page breaks are applicable before applying them. Bug: 1100308, 1053768 Change-Id: I987bf4ce42f7d0f5128cb01c30824214d9c12ea8 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2276432Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org> Commit-Queue: Morten Stenshorne <mstensho@chromium.org> Cr-Commit-Position: refs/heads/master@{#784139}

Named pages should only have an effect when paginated.
Need to check if page breaks are applicable before applying them. Bug: 1100308, 1053768 Change-Id: I987bf4ce42f7d0f5128cb01c30824214d9c12ea8 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2276432Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org> Commit-Queue: Morten Stenshorne <mstensho@chromium.org> Cr-Commit-Position: refs/heads/master@{#784139}
8b5b78ab · Morten Stenshorne · Commit Bot · aec26a82 · 8b5b78ab · 8b5b78ab
Commit 8b5b78ab authored Jun 30, 2020 by Morten Stenshorne Committed by Commit Bot Jun 30, 2020
2 changed files
--- a/third_party/blink/renderer/core/layout/layout_block_flow.cc
+++ b/third_party/blink/renderer/core/layout/layout_block_flow.cc
@@ -893,7 +893,7 @@ void LayoutBlockFlow::InsertForcedBreakBeforeChildIfNeeded(
  EBreakBetween class_a_break_point_value =
      child.ClassABreakPointValue(layout_info.PreviousBreakAfterValue());
-  if (page_name_has_changed)
+  if (page_name_has_changed && IsBreakBetweenControllable(EBreakBetween::kPage))
    class_a_break_point_value = EBreakBetween::kPage;
  if (IsForcedFragmentainerBreakValue(class_a_break_point_value)) {

--- a/third_party/blink/web_tests/external/wpt/css/css-multicol/named-page.html
+++ b/third_party/blink/web_tests/external/wpt/css/css-multicol/named-page.html
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1100308">
+<meta name="assert" content="The 'page' property should only have an effect if we're paginated, i.e. not inside multicol containers (unless we're also paginated)">
+<link rel="match" href="../reference/ref-filled-green-100px-square.xht">
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div style="columns:1; column-fill:auto; width:100px; height:100px; background:red;">
+  <div style="height:50px; background:green;"></div>
+  <div style="page:bogus; height:50px; background:green;"></div>
+</div>