Avoid stretching the parent of a column spanner.

Source/core/layout/LayoutMultiColumnFlowThreadTest.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 
 #include "core/layout/LayoutMultiColumnFlowThread.h"
 
 #include "core/layout/LayoutMultiColumnSet.h"
 #include "core/layout/LayoutMultiColumnSpannerPlaceholder.h"
@@ skipping 275 matching lines @@
 
 TEST_F(MultiColumnRenderingTest, columnSetAtBlockOffset)
 {
     setMulticolHTML("<div id='mc' style='line-height:100px;'>text<br>text<br>text<br>text<br>text<div id='spanner1'>spanner</div>text<br>text<div id='spanner2'>text<br>text</div>text</div>");
     LayoutMultiColumnFlowThread* flowThread = findFlowThread("mc");
     EXPECT_EQ(columnSetSignature(flowThread), "cscsc");
     LayoutMultiColumnSet* firstRow = flowThread->firstMultiColumnSet();
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(-10000)), firstRow); // negative overflow
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit()), firstRow);
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(499)), firstRow); // bottom of last line in first row.
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(599)), firstRow); // empty content in last column in first row
     LayoutMultiColumnSet* secondRow = firstRow->nextSiblingMultiColumnSet();
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(600)), secondRow);
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(799)), secondRow);
+    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(500)), secondRow);
+    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(699)), secondRow);
     LayoutMultiColumnSet* thirdRow = secondRow->nextSiblingMultiColumnSet();
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(800)), thirdRow);
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(899)), thirdRow); // bottom of last row
+    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(700)), thirdRow);
+    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(799)), thirdRow); // bottom of last row
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(10000)), thirdRow); // overflow
 }
 
 TEST_F(MultiColumnRenderingTest, columnSetAtBlockOffsetVerticalRl)
 {
     setMulticolHTML("<div id='mc' style='line-height:100px; -webkit-writing-mode:vertical-rl;'>text<br>text<br>text<br>text<br>text<div id='spanner1'>spanner</div>text<br>text<div id='spanner2'>text<br>text</div>text</div>");
     LayoutMultiColumnFlowThread* flowThread = findFlowThread("mc");
     EXPECT_EQ(columnSetSignature(flowThread), "cscsc");
     LayoutMultiColumnSet* firstRow = flowThread->firstMultiColumnSet();
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(-10000)), firstRow); // negative overflow
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit()), firstRow);
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(499)), firstRow); // bottom of last line in first row.
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(599)), firstRow); // empty content in last column in first row
     LayoutMultiColumnSet* secondRow = firstRow->nextSiblingMultiColumnSet();
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(600)), secondRow);
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(799)), secondRow);
+    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(500)), secondRow);
+    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(699)), secondRow);
     LayoutMultiColumnSet* thirdRow = secondRow->nextSiblingMultiColumnSet();
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(800)), thirdRow);
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(899)), thirdRow); // bottom of last row
+    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(700)), thirdRow);
+    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(799)), thirdRow); // bottom of last row
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(10000)), thirdRow); // overflow
 }
 
 TEST_F(MultiColumnRenderingTest, columnSetAtBlockOffsetVerticalLr)
 {
     setMulticolHTML("<div id='mc' style='line-height:100px; -webkit-writing-mode:vertical-lr;'>text<br>text<br>text<br>text<br>text<div id='spanner1'>spanner</div>text<br>text<div id='spanner2'>text<br>text</div>text</div>");
     LayoutMultiColumnFlowThread* flowThread = findFlowThread("mc");
     EXPECT_EQ(columnSetSignature(flowThread), "cscsc");
     LayoutMultiColumnSet* firstRow = flowThread->firstMultiColumnSet();
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(-10000)), firstRow); // negative overflow
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit()), firstRow);
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(499)), firstRow); // bottom of last line in first row.
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(599)), firstRow); // empty content in last column in first row
     LayoutMultiColumnSet* secondRow = firstRow->nextSiblingMultiColumnSet();
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(600)), secondRow);
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(799)), secondRow);
+    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(500)), secondRow);
+    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(699)), secondRow);
     LayoutMultiColumnSet* thirdRow = secondRow->nextSiblingMultiColumnSet();
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(800)), thirdRow);
-    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(899)), thirdRow); // bottom of last row
+    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(700)), thirdRow);
+    EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(799)), thirdRow); // bottom of last row
     EXPECT_EQ(flowThread->columnSetAtBlockOffset(LayoutUnit(10000)), thirdRow); // overflow
 }
 
 class MultiColumnTreeModifyingTest : public MultiColumnRenderingTest {
 public:
     void setMulticolHTML(const char*);
     void reparentLayoutObject(const char* newParentId, const char* childId, const char* insertBeforeId = nullptr);
     void destroyLayoutObject(LayoutObject* child);
     void destroyLayoutObject(const char* childId);
 };
@@ skipping 446 matching lines @@
 {
     setMulticolHTML("<div id='mc'>text<div id='spanner'><div class='s'></div></div>text</div>");
     EXPECT_EQ(columnSetSignature("mc"), "csc");
     destroyLayoutObject("spanner");
     EXPECT_EQ(columnSetSignature("mc"), "c");
 }
 
 } // anonymous namespace
 
 } // namespace blink