[IFC] text-overflow: ellipsis doesn't work with overflow: clip

https://bugs.webkit.org/show_bug.cgi?id=258265
<rdar://problem/111182654>

Reviewed by Simon Fraser.

https://drafts.csswg.org/css-overflow/#text-overflow
"
This property specifies rendering when inline content overflows its end line box edge
in the inline progression direction of its block container element ("the block") that
has overflow other than visible.
"

* LayoutTests/fast/css/empty-pseudo-class.html:
* LayoutTests/fast/inline/overflow-with-text-ellipsis-expected.html: Added.
* LayoutTests/fast/inline/overflow-with-text-ellipsis.html: Added.
* Source/WebCore/layout/formattingContexts/inline/InlineFormattingContext.cpp:
(WebCore::Layout::lineEndingEllipsisPolicy):

imported/w3c/web-platform-tests/css/css-ui/text-overflow-021.html: this never worked (revealing content as being scrolled in).

Canonical link: https://commits.webkit.org/265445@main

LayoutTests/TestExpectations

@@ -4639,6 +4639,7 @@ webkit.org/b/214299 imported/w3c/web-platform-tests/css/css-ui/appearance-menuli
 webkit.org/b/214299 imported/w3c/web-platform-tests/css/css-ui/outline-025.html [ ImageOnlyFailure ]
 webkit.org/b/214299 imported/w3c/web-platform-tests/css/css-ui/outline-026.html [ ImageOnlyFailure ]
 webkit.org/b/214299 imported/w3c/web-platform-tests/css/css-ui/text-overflow-ruby.html [ ImageOnlyFailure ]
+webkit.org/b/214299 imported/w3c/web-platform-tests/css/css-ui/text-overflow-021.html [ ImageOnlyFailure ]
 webkit.org/b/214299 imported/w3c/web-platform-tests/css/css-ui/webkit-appearance-menulist-button-002.tentative.html [ ImageOnlyFailure ]
 webkit.org/b/214299 imported/w3c/web-platform-tests/css/css-ui/resize-child-will-change-transform.html [ ImageOnlyFailure ]
 webkit.org/b/214299 imported/w3c/web-platform-tests/css/css-ui/resize-generated-content.html [ ImageOnlyFailure ]

LayoutTests/fast/inline/overflow-with-text-ellipsis-expected.html

@@ -0,0 +1,19 @@
+<style>
+div {
+  width: 30px;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  font-family: Monospace;
+  font-size: 20px;
+}
+
+div::-webkit-scrollbar {
+  width: 0px;
+  height: 0px;
+}
+</style>
+PASS if ellipsis show
+<div style="overflow: hidden">X&#8230;</div>
+<div style="overflow: clip">X&#8230;</div>
+<div style="overflow-x: scroll">X&#8230;</div>
+<div style="overflow: scroll">X&#8230;</div>

LayoutTests/fast/inline/overflow-with-text-ellipsis.html

@@ -0,0 +1,19 @@
+<style>
+div {
+  width: 30px;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  font-family: Monospace;
+  font-size: 20px;
+}
+div::-webkit-scrollbar {
+  width: 0px;
+  height: 0px;
+}
+
+</style>
+PASS if ellipsis show
+<div style="overflow: hidden">XXXX</div>
+<div style="overflow: clip">XXXX</div>
+<div style="overflow: auto">XXXX</div>
+<div style="overflow: scroll">XXXX</div>

Source/WebCore/layout/formattingContexts/inline/InlineFormattingContext.cpp

@@ -553,7 +553,7 @@ static LineEndingEllipsisPolicy lineEndingEllipsisPolicy(const RenderStyle& root
             return LineEndingEllipsisPolicy::WhenContentOverflowsInBlockDirection;
     }
     // Truncation is in effect when the block container has overflow other than visible.
-    if (rootStyle.overflowX() == Overflow::Hidden && rootStyle.textOverflow() == TextOverflow::Ellipsis)
+    if (rootStyle.overflowX() != Overflow::Visible && rootStyle.textOverflow() == TextOverflow::Ellipsis)
         return LineEndingEllipsisPolicy::WhenContentOverflowsInInlineDirection;
     return LineEndingEllipsisPolicy::No;
 }