[CSS Grid Layout] Ignore ::first-letter pseudo-element

Source/core/rendering/RenderBlock.cpp

Index: Source/core/rendering/RenderBlock.cpp
diff --git a/Source/core/rendering/RenderBlock.cpp b/Source/core/rendering/RenderBlock.cpp
index 3236fff5313b2a16e790d163ebeb88e54ca2d988..414359a084f79ce2553a04984cca8f5844285b36 100644
--- a/Source/core/rendering/RenderBlock.cpp
+++ b/Source/core/rendering/RenderBlock.cpp
@@ -3927,6 +3927,17 @@ int RenderBlock::lastLineBoxBaseline(LineDirectionMode lineDirection) const
     return -1;
 }
 
+static inline bool isRenderBlockFlowOrRenderButton(RenderObject* renderObject)
+{
+    // We include isRenderButton in this check because buttons are implemented
+    // using flex box but should still support first-line|first-letter.
+    // The flex box and grid specs requires that flex box and grid do not
+    // support first-line|first-letter, though.
+    // FIXME: Remove when buttons are implemented with align-items instead
+    // of flexbox.
+    return renderObject->isRenderBlockFlow() || renderObject->isRenderButton();
+}
+
 RenderBlock* RenderBlock::firstLineBlock() const
 {
     RenderBlock* firstLineBlock = const_cast<RenderBlock*>(this);
@@ -3936,15 +3947,9 @@ RenderBlock* RenderBlock::firstLineBlock() const
         if (hasPseudo)
             break;
         RenderObject* parentBlock = firstLineBlock->parent();
-        // We include isRenderButton in this check because buttons are
-        // implemented using flex box but should still support first-line. The
-        // flex box spec requires that flex box does not support first-line,
-        // though.
-        // FIXME: Remove when buttons are implemented with align-items instead
-        // of flexbox.
         if (firstLineBlock->isReplaced() || firstLineBlock->isFloating()
             || !parentBlock
-            || (!parentBlock->isRenderBlockFlow() && !parentBlock->isRenderButton()))
+            || !isRenderBlockFlowOrRenderButton(parentBlock))
             break;
         ASSERT_WITH_SECURITY_IMPLICATION(parentBlock->isRenderBlock());
         if (toRenderBlock(parentBlock)->firstChild() != firstLineBlock)
@@ -3990,21 +3995,15 @@ static inline RenderObject* findFirstLetterBlock(RenderBlock* start)
 {
     RenderObject* firstLetterBlock = start;
     while (true) {
-        // We include isRenderButton in these two checks because buttons are
-        // implemented using flex box but should still support first-letter.
-        // The flex box spec requires that flex box does not support
-        // first-letter, though.
-        // FIXME: Remove when buttons are implemented with align-items instead
-        // of flexbox.
         bool canHaveFirstLetterRenderer = firstLetterBlock->style()->hasPseudoStyle(FIRST_LETTER)
             && firstLetterBlock->canHaveGeneratedChildren()
-            && (!firstLetterBlock->isFlexibleBox() || firstLetterBlock->isRenderButton());
+            && isRenderBlockFlowOrRenderButton(firstLetterBlock);
         if (canHaveFirstLetterRenderer)
             return firstLetterBlock;
 
         RenderObject* parentBlock = firstLetterBlock->parent();
         if (firstLetterBlock->isReplaced() || !parentBlock
-            || (!parentBlock->isRenderBlockFlow() && !parentBlock->isRenderButton())) {
+            || !isRenderBlockFlowOrRenderButton(parentBlock)) {
             return 0;
         }
         ASSERT(parentBlock->isRenderBlock());
@@ -4176,7 +4175,7 @@ void RenderBlock::updateFirstLetter()
                 break;
             }
             currChild = currChild->nextSibling();
-        } else if (currChild->isReplaced() || currChild->isRenderButton() || currChild->isMenuList()) {
+        } else if (currChild->isReplaced() || currChild->isRenderButton() || currChild->isMenuList() || !isRenderBlockFlowOrRenderButton(firstLetterBlock)) {

[cbiesinger, 2014/08/08 03:28:12]

I'm confused, why do we want a break here if the firstLetterBlock is a
grid/flexbox? Maybe there should be a comment explaining that?

[Manuel Rego, 2014/08/08 12:55:27]

Yeah, I agree that it's confusing to add this in the middle of the while.

It seems simpler to move it after the while, and just check that
firstLetterBlock
is not a flexbox/grid there. Like, we've already done before in
findFirstLetterBlock().

I guess the new code is simpler to understand and the comment is already in
isRenderBlockFlowOrRenderButton().

BTW, if we don't do this, the example with a container will fail, and
::first-letter
pseudo-element from the flexbox/grid will be used in the items.
Because of, as the container has already defined ::first-letter, while
navigating
the children in the previous while, we'll be reaching the flex/grid item, and
we'll
be using the ::first-letter definition from the flexbox/grid. Which is wrong.

             break;
         } else if (currChild->style()->hasPseudoStyle(FIRST_LETTER) && currChild->canHaveGeneratedChildren())  {
             // We found a lower-level node with first-letter, which supersedes the higher-level style