Behave more normally for content taller than the fragmentainer it's in.

Source/core/layout/LayoutBlockFlow.cpp

Index: Source/core/layout/LayoutBlockFlow.cpp
diff --git a/Source/core/layout/LayoutBlockFlow.cpp b/Source/core/layout/LayoutBlockFlow.cpp
index a17579a659121ceb0e7d760f61a1d7c7a88f2fb2..33114e7ebedcb0be4bb28bc899de7a3c27c2b25c 100644
--- a/Source/core/layout/LayoutBlockFlow.cpp
+++ b/Source/core/layout/LayoutBlockFlow.cpp
@@ -775,14 +775,8 @@ void LayoutBlockFlow::adjustLinePositionForPagination(RootInlineBox& lineBox, La
     lineBox.setPaginationStrut(0);
     lineBox.setIsFirstAfterPageBreak(false);
     LayoutUnit pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset);
-    bool hasUniformPageLogicalHeight = !flowThread || flowThread->columnSetsHaveUniformLogicalHeight();
-    // If lineHeight is greater than pageLogicalHeight, but logicalVisualOverflow.height() still fits, we are
-    // still going to add a strut, so that the visible overflow fits on a single page.
-    if (!pageLogicalHeight || (hasUniformPageLogicalHeight && logicalVisualOverflow.height() > pageLogicalHeight)) {
-        // FIXME: In case the line aligns with the top of the page (or it's slightly shifted downwards) it will not be marked as the first line in the page.
-        // From here, the fix is not straightforward because it's not easy to always determine when the current line is the first in the page.
+    if (!pageLogicalHeight)
         return;
-    }
     LayoutUnit remainingLogicalHeight = pageRemainingLogicalHeightForOffset(logicalOffset, ExcludePageBoundary);
 
     int lineIndex = lineCount(&lineBox);
@@ -796,7 +790,7 @@ void LayoutBlockFlow::adjustLinePositionForPagination(RootInlineBox& lineBox, La
             remainingLogicalHeight -= std::min(lineHeight - pageLogicalHeight, std::max<LayoutUnit>(0, logicalVisualOverflow.y() - lineBox.lineTopWithLeading()));
         }
         LayoutUnit totalLogicalHeight = lineHeight + std::max<LayoutUnit>(0, logicalOffset);
-        LayoutUnit pageLogicalHeightAtNewOffset = hasUniformPageLogicalHeight ? pageLogicalHeight : pageLogicalHeightForOffset(logicalOffset + remainingLogicalHeight);
+        LayoutUnit pageLogicalHeightAtNewOffset = pageLogicalHeightForOffset(logicalOffset + remainingLogicalHeight);
         setPageBreak(logicalOffset, lineHeight - remainingLogicalHeight);
         if (((lineBox == firstRootBox() && totalLogicalHeight < pageLogicalHeightAtNewOffset) || (!style()->hasAutoOrphans() && style()->orphans() >= lineIndex))
             && !isOutOfFlowPositioned() && !isTableCell()) {
@@ -826,7 +820,7 @@ LayoutUnit LayoutBlockFlow::adjustForUnsplittableChild(LayoutBox& child, LayoutU
     LayoutUnit childLogicalHeight = logicalHeightForChild(child) + (includeMargins ? marginBeforeForChild(child) + marginAfterForChild(child) : LayoutUnit());
     LayoutUnit pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset);
     updateMinimumPageHeight(logicalOffset, childLogicalHeight);
-    if (!pageLogicalHeight || childLogicalHeight > pageLogicalHeight)
+    if (!pageLogicalHeight)
         return logicalOffset;
     LayoutUnit remainingLogicalHeight = pageRemainingLogicalHeightForOffset(logicalOffset, ExcludePageBoundary);
     if (remainingLogicalHeight < childLogicalHeight)