Changeset 266996 in webkit

Timestamp:

Sep 13, 2020 9:46:12 AM (4 years ago)

Author:

Alan Bujtas

Message:

[LFC][Tree building] Table rows may not have any children.
​https://bugs.webkit.org/show_bug.cgi?id=216456

Reviewed by Antti Koivisto.

Cover the case when the table row has no children at all (call numberOfCellsPerRow.append() on evey row when needed).

• layout/layouttree/LayoutTreeBuilder.cpp:

(WebCore::Layout::TreeBuilder::buildTableStructure):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• layout/layouttree/LayoutTreeBuilder.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2020-09-13  Zalan Bujtas  <zalan@apple.com>
+
+        [LFC][Tree building] Table rows may not have any children.
+        https://bugs.webkit.org/show_bug.cgi?id=216456
+
+        Reviewed by Antti Koivisto.
+
+        Cover the case when the table row has no children at all (call numberOfCellsPerRow.append() on evey row when needed).
+
+        * layout/layouttree/LayoutTreeBuilder.cpp:
+        (WebCore::Layout::TreeBuilder::buildTableStructure):
+
 2020-09-13  Zalan Bujtas  <zalan@apple.com>
 

trunk/Source/WebCore/layout/layouttree/LayoutTreeBuilder.cpp

@@ -338 +338 @@
         // Find the max number of columns and fill in the gaps.
         size_t maximumColumns = 0;
+        size_t currentRow = 0;
         Vector<size_t> numberOfCellsPerRow;
-        size_t currentRow = 0;
         for (auto& rowBox : childrenOfType<ContainerBox>(tableBody)) {
+            if (numberOfCellsPerRow.size() <= currentRow) {
+                // Ensure we always have a vector entry for the current row -even when the row is empty.
+                numberOfCellsPerRow.append({ });
+            }
             for (auto& cellBox : childrenOfType<ContainerBox>(rowBox)) {
+                auto numberOfSpannedColumns = cellBox.columnSpan();
                 for (size_t rowSpan = 0; rowSpan < cellBox.rowSpan(); ++rowSpan) {
-                    if (numberOfCellsPerRow.size() <= currentRow + rowSpan)
-                        numberOfCellsPerRow.append(cellBox.columnSpan());
-                    else
-                        numberOfCellsPerRow[currentRow + rowSpan] += cellBox.columnSpan();
+                    auto rowIndexWithSpan = currentRow + rowSpan;
+                    if (numberOfCellsPerRow.size() <= rowIndexWithSpan) {
+                        // This is where we advance from the current row by having a row spanner.
+                        numberOfCellsPerRow.append(numberOfSpannedColumns);
+                        continue;
+                    }
+                    numberOfCellsPerRow[rowIndexWithSpan] += numberOfSpannedColumns;
                 }
             }