Bug 1797792 - Tweak HTMLOptionsCollection.length limit. r=smaug

As per the discussion in whatwg/html#8347 Differential Revision: https://phabricator.services.mozilla.com/D160544
mozilla · Oct 28, 2022 · 30558e6 · 30558e6
1 parent cd13faf
commit 30558e6
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Showing 2 changed files with 16 additions and 8 deletions.
diff --git a/dom/html/HTMLSelectElement.cpp b/dom/html/HTMLSelectElement.cpp
@@ -566,25 +566,25 @@ void HTMLSelectElement::GetType(nsAString& aType) {
   }
 }
 
-#define MAX_DYNAMIC_SELECT_LENGTH 10000
-
 void HTMLSelectElement::SetLength(uint32_t aLength, ErrorResult& aRv) {
+  constexpr uint32_t kMaxDynamicSelectLength = 100000;
+
   uint32_t curlen = Length();
 
   if (curlen > aLength) {  // Remove extra options
     for (uint32_t i = curlen; i > aLength; --i) {
       Remove(i - 1);
     }
   } else if (aLength > curlen) {
-    if (aLength > MAX_DYNAMIC_SELECT_LENGTH) {
+    if (aLength > kMaxDynamicSelectLength) {
       nsAutoString strOptionsLength;
       strOptionsLength.AppendInt(aLength);
 
       nsAutoString strLimit;
-      strLimit.AppendInt(MAX_DYNAMIC_SELECT_LENGTH);
+      strLimit.AppendInt(kMaxDynamicSelectLength);
 
       nsContentUtils::ReportToConsole(
-          nsIScriptError::warningFlag, "DOM"_ns, GetOwnerDocument(),
+          nsIScriptError::warningFlag, "DOM"_ns, OwnerDoc(),
           nsContentUtils::eDOM_PROPERTIES,
           "SelectOptionsLengthAssignmentWarning", {strOptionsLength, strLimit});
       return;

diff --git a/testing/web-platform/tests/html/select/options-length-too-large.html b/testing/web-platform/tests/html/select/options-length-too-large.html
@@ -23,13 +23,21 @@
     });
 
     test(function() {
-        mySelect.options.length = 10001;
+        mySelect.options.length = 100001;
         assert_equals(mySelect.options.length, 3, "Length of <select> should remain unchanged");
     });
 
     test(function() {
-        mySelect.options.length = 10000;
-        assert_equals(mySelect.options.length, 10000, "Length of <select> should be 10,000");
+        mySelect.options.length = 100000;
+        assert_equals(mySelect.options.length, 100000, "Length of <select> should be 10,0000");
+    });
+
+    test(function() {
+        mySelect.appendChild(new Option());
+        mySelect.appendChild(new Option());
+        assert_equals(mySelect.options.length, 100002, "Manual expansion still works");
+        mySelect.options.length = 100001;
+        assert_equals(mySelect.options.length, 100001, "Truncation works if over the limit");
     });
     </script>
   </body>