Return nonzero on parsing empty url.

Fixes: https://github.com/nodejs/http-parser/issues/414
PR-URL: https://github.com/nodejs/http-parser/pull/424
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

http_parser.c

@@ -2314,6 +2314,10 @@ http_parser_parse_url(const char *buf, size_t buflen, int is_connect,
   enum http_parser_url_fields uf, old_uf;
   int found_at = 0;
 
+  if (buflen == 0) {
+    return 1;
+  }
+
   u->port = u->field_set = 0;
   s = is_connect ? s_req_server_start : s_req_spaces_before_url;
   old_uf = UF_MAX;

test.c

@@ -3250,6 +3250,24 @@ const struct url_test url_tests[] =
   ,.rv=1 /* s_dead */
   }
 
+, {.name="empty url"
+  ,.url=""
+  ,.is_connect=0
+  ,.rv=1
+  }
+
+, {.name="NULL url"
+  ,.url=NULL
+  ,.is_connect=0
+  ,.rv=1
+  }
+
+, {.name="full of spaces url"
+  ,.url="  "
+  ,.is_connect=0
+  ,.rv=1
+  }
+
 #if HTTP_PARSER_STRICT
 
 , {.name="tab in URL"
@@ -3334,7 +3352,7 @@ test_parse_url (void)
     memset(&u, 0, sizeof(u));
 
     rv = http_parser_parse_url(test->url,
-                               strlen(test->url),
+                               test->url ? strlen(test->url) : 0,
                                test->is_connect,
                                &u);