Changeset 262363 in webkit

Timestamp:

May 31, 2020 11:02:42 AM (4 years ago)

Author:

Alan Bujtas

Message:

[iBooks] Empty pages appear in book
​https://bugs.webkit.org/show_bug.cgi?id=212573
<rdar://problem/62912623>

Reviewed by Antti Koivisto.

Source/WebCore:

Do not add a page break for orphan content unless the line does not fit anymore.

Test: fast/multicol/orphans-ignored.html

• rendering/SimpleLineLayoutPagination.cpp:

(WebCore::SimpleLineLayout::setPageBreakForLine):
(WebCore::SimpleLineLayout::adjustLinePositionsForPagination):

LayoutTests:

• fast/multicol/orphans-ignored-expected.html: Added.
• fast/multicol/orphans-ignored.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/multicol/orphans-ignored-expected.html (added)
• LayoutTests/fast/multicol/orphans-ignored.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/SimpleLineLayoutPagination.cpp (modified) (3 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2020-05-31  Zalan Bujtas  <zalan@apple.com>
+
+        [iBooks] Empty pages appear in book
+        https://bugs.webkit.org/show_bug.cgi?id=212573
+        <rdar://problem/62912623>
+
+        Reviewed by Antti Koivisto.
+
+        * fast/multicol/orphans-ignored-expected.html: Added.
+        * fast/multicol/orphans-ignored.html: Added.
+
 2020-05-31  Rob Buis  <rbuis@igalia.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2020-05-31  Zalan Bujtas  <zalan@apple.com>
+
+        [iBooks] Empty pages appear in book
+        https://bugs.webkit.org/show_bug.cgi?id=212573
+        <rdar://problem/62912623>
+
+        Reviewed by Antti Koivisto.
+
+        Do not add a page break for orphan content unless the line does not fit anymore.
+
+        Test: fast/multicol/orphans-ignored.html
+
+        * rendering/SimpleLineLayoutPagination.cpp:
+        (WebCore::SimpleLineLayout::setPageBreakForLine):
+        (WebCore::SimpleLineLayout::adjustLinePositionsForPagination):
+
 2020-05-31  Rob Buis  <rbuis@igalia.com>
 

trunk/Source/WebCore/rendering/SimpleLineLayoutPagination.cpp

@@ -96 +96 @@
 
 static void setPageBreakForLine(unsigned lineBreakIndex, PaginatedLines& lines, RenderBlockFlow& flow, Layout::SimpleLineStruts& struts,
-    bool atTheTopOfColumnOrPage)
+    bool atTheTopOfColumnOrPage, bool lineDoesNotFit)
 {
     auto line = lines.at(lineBreakIndex);
@@ -102 +102 @@
     auto& style = flow.style();
     auto firstLineDoesNotFit = !lineBreakIndex && line.height < flow.pageLogicalHeightForOffset(line.top);
-    auto orphanDoesNotFit = !style.hasAutoOrphans() && style.orphans() > (short)lineBreakIndex;
-    if (firstLineDoesNotFit || orphanDoesNotFit) {
+    auto moveOrphanToNextColumn = lineDoesNotFit && !style.hasAutoOrphans() && style.orphans() > (short)lineBreakIndex;
+    if (firstLineDoesNotFit || moveOrphanToNextColumn) {
         auto firstLine = lines.first();
         auto firstLineOverflowRect = computeOverflow(flow, LayoutRect(0_lu, firstLine.top, 0_lu, firstLine.height));
@@ -147 +147 @@
         auto remainingHeight = flow.pageRemainingLogicalHeightForOffset(line.top, RenderBlockFlow::ExcludePageBoundary);
         auto atTheTopOfColumnOrPage = flow.pageLogicalHeightForOffset(line.top) == remainingHeight;
-        if (line.height > remainingHeight || (atTheTopOfColumnOrPage && lineIndex)) {
+        auto lineDoesNotFit = line.height > remainingHeight;
+        if (lineDoesNotFit || (atTheTopOfColumnOrPage && lineIndex)) {
             auto lineBreakIndex = computeLineBreakIndex(lineIndex, lineCount, orphans, widows, struts);
             // Are we still at the top of the column/page?
             atTheTopOfColumnOrPage = atTheTopOfColumnOrPage ? lineIndex == lineBreakIndex : false;
-            setPageBreakForLine(lineBreakIndex, lines, flow, struts, atTheTopOfColumnOrPage);
+            setPageBreakForLine(lineBreakIndex, lines, flow, struts, atTheTopOfColumnOrPage, lineDoesNotFit);
             // Recompute line positions that we already visited but widow break pushed them to a new page.
             for (auto i = lineBreakIndex; i < lines.size(); ++i)