Do not assume that an absolute positioned block box's height is alway…

…s resolvable

https://bugs.webkit.org/show_bug.cgi?id=241213

Reviewed by Simon Fraser.

1. While the ICB (RenderView) always has fixed height/width, the RenderStyle values are set to auto.
2. It's incorrect to assume that we can always resolve the height for an absolute positioned box (e.g. it may have a "height: auto" relative positioned containing block)

* LayoutTests/fast/block/fill-available-with-absolute-position-expected.html: Added.
* LayoutTests/fast/block/fill-available-with-absolute-position.html: Added.
* Source/WebCore/rendering/RenderBox.cpp:
(WebCore::RenderBox::computeIntrinsicLogicalContentHeightUsing const):
(WebCore::RenderBox::computePositionedLogicalHeightUsing const):

Canonical link: https://commits.webkit.org/251215@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@295124 268f45cc-cd09-0410-ab3c-d52691b4dbfc

LayoutTests/fast/block/fill-available-with-absolute-position-expected.html

@@ -0,0 +1,9 @@
+<style>
+div { 
+  width: 10px;
+  height: 100%;
+  background-color: green;
+  position: absolute;
+}
+</style>
+<div></div>

LayoutTests/fast/block/fill-available-with-absolute-position.html

@@ -0,0 +1,15 @@
+<style>
+.fill { 
+  width: 10px;
+  background-color: green;
+  height: -webkit-fill-available;
+  position: absolute;
+}
+.relative-containing-block {
+  position: relative;
+}
+</style>
+<div class=fill></div>
+<div class=relative-containing-block>
+  <div class=fill style="background-color: red"></div>
+</div>

Source/WebCore/rendering/RenderBox.cpp

@@ -3281,6 +3281,8 @@ std::optional<LayoutUnit> RenderBox::computeIntrinsicLogicalContentHeightUsing(L
             // Until then, this is mostly just guesswork.
             if (!containingBlock)
                 return false;
+            if (is<RenderView>(containingBlock))
+                return true;
             auto containingBlockHasSpecifiedSpace = [&] {
                 auto isOrthogonal = WebCore::isOrthogonal(*this, *containingBlock);
                 auto& style = containingBlock->style();
@@ -4478,7 +4480,7 @@ void RenderBox::computePositionedLogicalHeightUsing(SizeType heightType, Length
         logicalHeightIsAuto = false;
     } else {
         if (logicalHeightLength.isIntrinsic())
-            resolvedLogicalHeight = adjustContentBoxLogicalHeightForBoxSizing(computeIntrinsicLogicalContentHeightUsing(logicalHeightLength, contentLogicalHeight, bordersPlusPadding).value());
+            resolvedLogicalHeight = adjustContentBoxLogicalHeightForBoxSizing(computeIntrinsicLogicalContentHeightUsing(logicalHeightLength, contentLogicalHeight, bordersPlusPadding).value_or(0_lu));
         else if (fromAspectRatio) {
             resolvedLogicalHeight = blockSizeFromAspectRatio(horizontalBorderAndPaddingExtent(), verticalBorderAndPaddingExtent(), style().logicalAspectRatio(), style().boxSizingForAspectRatio(), logicalWidth());
             resolvedLogicalHeight = std::max(LayoutUnit(), resolvedLogicalHeight - bordersPlusPadding);