fixup

lib/fetch/headers.js

@@ -276,6 +276,9 @@ class HeadersList {
       const firstValue = iterator.next().value
       // set [name, value] to first index.
       array[0] = [firstValue[0], firstValue[1].value]
+      // https://fetch.spec.whatwg.org/#concept-header-list-sort-and-combine
+      // 3.2.2. Assert: value is non-null.
+      assert(firstValue[1].value !== null)
       for (
         let i = 1, j = 0, right = 0, left = 0, pivot = 0, x, value;
         i < size;
@@ -287,7 +290,7 @@ class HeadersList {
         x = array[i] = [value[0], value[1].value]
         // https://fetch.spec.whatwg.org/#concept-header-list-sort-and-combine
         // 3.2.2. Assert: value is non-null.
-        assert(value[1].value !== null)
+        assert(x[1] !== null)
         left = 0
         right = i
         // binary search