Version 5.7.440.1 (cherry-pick)

src/runtime/runtime-i18n.cc

Index: src/runtime/runtime-i18n.cc
diff --git a/src/runtime/runtime-i18n.cc b/src/runtime/runtime-i18n.cc
index 2d0c55eb217b1c328e09633d763f9c8d81c7bf8e..7554f99cbb7dd8f46cabe846db49e966173607bd 100644
--- a/src/runtime/runtime-i18n.cc
+++ b/src/runtime/runtime-i18n.cc
@@ -865,8 +865,6 @@ MUST_USE_RESULT Object* LocaleConvertCase(Handle<String> s, Isolate* isolate,
   Handle<SeqTwoByteString> result;
   std::unique_ptr<uc16[]> sap;
 
-  if (dest_length == 0) return isolate->heap()->empty_string();
-
   // This is not a real loop. It'll be executed only once (no overflow) or
   // twice (overflow).
   for (int i = 0; i < 2; ++i) {
@@ -1088,7 +1086,7 @@ RUNTIME_FUNCTION(Runtime_StringToUpperCaseI18N) {
   int32_t length = s->length();
   s = String::Flatten(s);
 
-  if (s->HasOnlyOneByteChars() && length > 0) {
+  if (s->HasOnlyOneByteChars()) {
     Handle<SeqOneByteString> result =
         isolate->factory()->NewRawOneByteString(length).ToHandleChecked();