tor-browser

commit b25bbe45423b7a575e92ebc47f95e2b1a654b8de
parent 3dd2b930b2583ecf67979ff31cb2a28414b1f526
Author: Emilio Cobos Álvarez <emilio@crisal.io>
Date:   Thu,  8 Jan 2026 07:39:39 +0000

Bug 2008625 - Don't unconditionally fall back to single inserts for ::first-letter. r=TYLin,layout-reviewers

This fixes the regression making us go through the same codepath as
before, but I think this assertion is fishy, see details on the bug.

Differential Revision: https://phabricator.services.mozilla.com/D278121

Diffstat:
M
layout/base/nsCSSFrameConstructor.cpp
 | 
15
---------------
A
testing/web-platform/tests/css/css-multicol/crashtests/first-letter-column-span-fieldset.html
 | 
16
++++++++++++++++

2 files changed, 16 insertions(+), 15 deletions(-)
diff --git a/layout/base/nsCSSFrameConstructor.cpp b/layout/base/nsCSSFrameConstructor.cpp
@@ -6385,21 +6385,6 @@ void nsCSSFrameConstructor::ContentRangeInserted(nsIContent* aStartChild,
       // and creating frames.  We need to reget our prevsibling, parent frame,
       // etc.
       prevSibling = GetInsertionPrevSibling(&insertion, aStartChild, &isAppend);
-
-      // Need check whether a range insert is still safe.
-      if (!isSingleInsert) {
-        // Need to recover the letter frames first.
-        RecoverLetterFrames(state.mFloatedList.mContainingBlock);
-
-        // must fall back to a single ContertInserted for each child in the
-        // range
-        LAYOUT_PHASE_TEMP_EXIT();
-        IssueSingleInsertNofications(aStartChild, aEndChild,
-                                     InsertionKind::Sync);
-        LAYOUT_PHASE_TEMP_REENTER();
-        return;
-      }
-
       frameType = insertion.mParentFrame->Type();
     }
   }
diff --git a/testing/web-platform/tests/css/css-multicol/crashtests/first-letter-column-span-fieldset.html b/testing/web-platform/tests/css/css-multicol/crashtests/first-letter-column-span-fieldset.html
@@ -0,0 +1,16 @@
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=2008625">
+<style>
+*:last-of-type {
+  columns: 474px 1;
+}
+*:valid {
+  column-span: all;
+}
+*::first-letter { }
+</style>
+<data>
+<form></form>
+</data>
+<u>
+<fieldset></fieldset>
+</u>