Bug 1442506: Adjust assertion to allow empty appends. r=xidorn

Deletion at the end of a text-node ends up translated to an empty append. It's harmless though. Reviewers: xidorn Bug #: 1442506 Differential Revision: https://phabricator.services.mozilla.com/D667 MozReview-Commit-ID: DqheOYVWx8o
2018-03-02 12:07:24 +01:00 · 2018-03-02 12:07:24 +01:00 · 549e302e25
--- a/layout/base/RestyleManager.cpp
+++ b/layout/base/RestyleManager.cpp
@ -207,7 +207,7 @@ WhitespaceOnlyChangedOnAppend(const CharT* aBuffer,
                              size_t aOldLength,
                              size_t aNewLength)
 {
-  MOZ_ASSERT(aOldLength < aNewLength);
+  MOZ_ASSERT(aOldLength <= aNewLength);
  if (!WhitespaceOnly(aBuffer, aOldLength)) {
    // The old text was already not whitespace-only.
    return false;
--- a/layout/base/crashtests/1442506.html
+++ b/layout/base/crashtests/1442506.html
@ -0,0 +1,10 @@
+<script>
+function go() {
+  var b = window.getSelection();
+  var c = document.getSelection();
+  b.setBaseAndExtent(document.getElementById("a"), 0, document.body.firstChild, 1);
+  c.deleteFromDocument();
+}
+</script>
+<body onload=go()>
+<p id="a">
--- a/layout/base/crashtests/crashtests.list
+++ b/layout/base/crashtests/crashtests.list
@ -525,3 +525,4 @@ load 1429961.html
 load 1435015.html
 load 1429962.html
 pref(dom.webcomponents.shadowdom.enabled,true) load 1439016.html
+load 1442506.html