Trim trailing whitespace in cookie value: JavaNetCookieJar to avoid crash

[vansh1sh]

When JavaNetCookieJar receives a Cookie header from a CookieHandler with a quoted value that has trailing whitespace, for example:

Cookie: token="abc123 "

the value is unquoted to abc123 (with a trailing space), and Cookie.Builder.value currently throws IllegalArgumentException("value is not trimmed").

This PR makes decodeHeaderAsJavaNetCookies minimally tolerant of that case by trimming the value after unquoting:

// Minimal normalisation so Cookie.Builder doesn't crash on values like "abc123 ".
value = value.trim()

It also adds a regression test to okhttp/src/jvmTest/kotlin/okhttp3/CookiesTest.kt

Fixes #9373.

[yschimke]

Looks safe enough, but would like to confirm both paths, via a Response with Set-Cookie and the path here via injecting directly into CookieHandler.

Is there a particular CookieHandler that has this issue?

We should fix anyway, but I'm curious if this is just a theoretical bug.

[yschimke]

This is testing injecting a Cookie via CookieHandler. I can't reproduce via an actual request/response stored to the cookieJar, so I'm assuming this is only a problem with a shared or custom CookieHandler?

Can we add a test to confirm, something like

  @Test
  fun receiveAndSendUntrimmedCookie() {
    server.enqueue(
      MockResponse
        .Builder()
        .addHeader("Set-Cookie", "a=\"android \"")
        .build(),
    )
    server.enqueue(MockResponse())
    val cookieManager = CookieManager(null, CookiePolicy.ACCEPT_ORIGINAL_SERVER)
    client =
      client
        .newBuilder()
        .cookieJar(JavaNetCookieJar(cookieManager))
        .build()
    get(urlWithIpAddress(server, "/"))
    val request1 = server.takeRequest()
    assertThat(request1.headers["Cookie"]).isNull()
    get(urlWithIpAddress(server, "/"))
    val request2 = server.takeRequest()
    assertThat(request2.headers["Cookie"]).isEqualTo("a=android")
  }