url: fix windows drive letter handling

Address issue with Windows drive letter handling that was
causing es-module test suite to fail.

PR-URL: #15490
Ref: whatwg/url#343
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Author: Benjamin Coe

src/node_url.cc

@@ -552,6 +552,19 @@ static inline bool IsSpecial(std::string scheme) {
   return false;
 }
 
+// https://url.spec.whatwg.org/#start-with-a-windows-drive-letter
+static inline bool StartsWithWindowsDriveLetter(const char* p,
+                                                const char* end) {
+  const size_t length = end - p;
+  return length >= 2 &&
+    IsWindowsDriveLetter(p[0], p[1]) &&
+    (length == 2 ||
+      p[2] == '/' ||
+      p[2] == '\\' ||
+      p[2] == '?' ||
+      p[2] == '#');
+}
+
 static inline int NormalizePort(std::string scheme, int p) {
 #define XX(name, port) if (scheme == name && p == port) return -1;
   SPECIALS(XX);
@@ -1198,6 +1211,7 @@ void URL::Parse(const char* input,
     bool special = (url->flags & URL_FLAGS_SPECIAL);
     bool cannot_be_base;
     const bool special_back_slash = (special && ch == '\\');
+
     switch (state) {
       case kSchemeStart:
         if (IsASCIIAlpha(ch)) {
@@ -1667,13 +1681,7 @@ void URL::Parse(const char* input,
               state = kFragment;
               break;
             default:
-              if ((remaining == 0 ||
-                   !IsWindowsDriveLetter(ch, p[1]) ||
-                   (remaining >= 2 &&
-                    p[2] != '/' &&
-                    p[2] != '\\' &&
-                    p[2] != '?' &&
-                    p[2] != '#'))) {
+              if (!StartsWithWindowsDriveLetter(p, end)) {
                 if (base->flags & URL_FLAGS_HAS_HOST) {
                   url->flags |= URL_FLAGS_HAS_HOST;
                   url->host = base->host;
@@ -1697,7 +1705,8 @@ void URL::Parse(const char* input,
           state = kFileHost;
         } else {
           if (has_base &&
-              base->scheme == "file:") {
+              base->scheme == "file:" &&
+              !StartsWithWindowsDriveLetter(p, end)) {
             if (IsNormalizedWindowsDriveLetter(base->path[0])) {
               url->flags |= URL_FLAGS_HAS_PATH;
               url->path.push_back(base->path[0]);