Add support for following HTTP 307 temporary redirects.

Fixes Android bug 41739.

src/main/java/com/squareup/okhttp/internal/http/HttpURLConnectionImpl.java

@@ -60,6 +60,10 @@ import static com.squareup.okhttp.internal.Util.getEffectivePort;
  * is currently connected to a server.
  */
 public class HttpURLConnectionImpl extends HttpURLConnection {
+
+  /** Numeric status code, 307: Temporary Redirect. */
+  static final int HTTP_TEMP_REDIRECT = 307;
+
   /**
    * How many redirects should we follow? Chrome follows 21; Firefox, curl,
    * and wget follow 20; Safari follows 16; and HTTP/1.0 recommends 5.
@@ -400,7 +404,8 @@ public class HttpURLConnectionImpl extends HttpURLConnection {
     Proxy selectedProxy = httpEngine.connection != null
         ? httpEngine.connection.getProxy()
         : requestedProxy;
-    switch (getResponseCode()) {
+    final int responseCode = getResponseCode();
+    switch (responseCode) {
       case HTTP_PROXY_AUTH:
         if (selectedProxy.type() != Proxy.Type.HTTP) {
           throw new ProtocolException("Received HTTP_PROXY_AUTH (407) code while not using proxy");
@@ -415,12 +420,18 @@ public class HttpURLConnectionImpl extends HttpURLConnection {
       case HTTP_MOVED_PERM:
       case HTTP_MOVED_TEMP:
       case HTTP_SEE_OTHER:
+      case HTTP_TEMP_REDIRECT:
         if (!getInstanceFollowRedirects()) {
           return Retry.NONE;
         }
         if (++redirectionCount > MAX_REDIRECTS) {
           throw new ProtocolException("Too many redirects: " + redirectionCount);
         }
+        if (responseCode == HTTP_TEMP_REDIRECT && !method.equals("GET") && !method.equals("HEAD")) {
+          // "If the 307 status code is received in response to a request other than GET or HEAD,
+          // the user agent MUST NOT automatically redirect the request"
+          return Retry.NONE;
+        }
         String location = getHeaderField("Location");
         if (location == null) {
           return Retry.NONE;

src/test/java/com/squareup/okhttp/internal/http/URLConnectionTest.java

@@ -1731,6 +1731,70 @@ public final class URLConnectionTest {
     assertEquals(1, server.getRequestCount());
   }
 
+  @Test public void response307WithGet() throws Exception {
+    test307Redirect("GET");
+  }
+
+  @Test public void response307WithHead() throws Exception {
+    test307Redirect("HEAD");
+  }
+
+  @Test public void response307WithOptions() throws Exception {
+    test307Redirect("OPTIONS");
+  }
+
+  @Test public void response307WithPost() throws Exception {
+    test307Redirect("POST");
+  }
+
+  private void test307Redirect(String method) throws Exception {
+    MockResponse response1 = new MockResponse()
+        .setResponseCode(HttpURLConnectionImpl.HTTP_TEMP_REDIRECT)
+        .addHeader("Location: /page2");
+    if (!method.equals("HEAD")) {
+      response1.setBody("This page has moved!");
+    }
+    server.enqueue(response1);
+    server.enqueue(new MockResponse().setBody("Page 2"));
+    server.play();
+
+    HttpURLConnection connection = client.open(server.getUrl("/page1"));
+    connection.setRequestMethod(method);
+    byte[] requestBody = { 'A', 'B', 'C', 'D' };
+    if (method.equals("POST")) {
+      connection.setDoOutput(true);
+      OutputStream outputStream = connection.getOutputStream();
+      outputStream.write(requestBody);
+      outputStream.close();
+    }
+
+    String response = readAscii(connection.getInputStream(), Integer.MAX_VALUE);
+
+    RecordedRequest page1 = server.takeRequest();
+    assertEquals(method + " /page1 HTTP/1.1", page1.getRequestLine());
+
+    if (method.equals("GET")) {
+        assertEquals("Page 2", response);
+    } else if (method.equals("HEAD"))  {
+        assertTrue(response.isEmpty());
+    } else {
+      // Methods other than GET/HEAD shouldn't follow the redirect
+      if (method.equals("POST")) {
+        assertTrue(connection.getDoOutput());
+        assertEquals(Arrays.toString(requestBody), Arrays.toString(page1.getBody()));
+      }
+      assertEquals(1, server.getRequestCount());
+      assertEquals("This page has moved!", response);
+      return;
+    }
+
+    // GET/HEAD requests should have followed the redirect with the same method
+    assertFalse(connection.getDoOutput());
+    assertEquals(2, server.getRequestCount());
+    RecordedRequest page2 = server.takeRequest();
+    assertEquals(method + " /page2 HTTP/1.1", page2.getRequestLine());
+  }
+
   @Test public void follow20Redirects() throws Exception {
     for (int i = 0; i < 20; i++) {
       server.enqueue(new MockResponse().setResponseCode(HttpURLConnection.HTTP_MOVED_TEMP)