fix: Correctly handling chunked response streams with gzip (#990)

Previous implementation doesn't properly cleanup the last chunk of a chunked response when the response is also gzipped. This in turns prevents proper connection reuse. Fixes #367

Author: hiranya911

google-http-client/src/main/java/com/google/api/client/http/HttpResponse.java

@@ -353,8 +353,13 @@ public InputStream getContent() throws IOException {
  if (!returnRawInputStream && this.contentEncoding != null) {
  String oontentencoding = this.contentEncoding.trim().toLowerCase(Locale.ENGLISH);
  if (CONTENT_ENCODING_GZIP.equals(oontentencoding) || CONTENT_ENCODING_XGZIP.equals(oontentencoding)) {
+ // Wrap the original stream in a ConsumingInputStream before passing it to
+ // GZIPInputStream. The GZIPInputStream leaves content unconsumed in the original
+ // stream (it almost always leaves the last chunk unconsumed in chunked responses).
+ // ConsumingInputStream ensures that any unconsumed bytes are read at close.
+ // GZIPInputStream.close() --> ConsumingInputStream.close() --> exhaust(ConsumingInputStream)
  lowLevelResponseContent =
- new ConsumingInputStream(new GZIPInputStream(lowLevelResponseContent));
+ new GZIPInputStream(new ConsumingInputStream(lowLevelResponseContent));
  }
  }
  // logging (wrap content with LoggingInputStream)

google-http-client/src/test/java/com/google/api/client/http/HttpResponseTest.java

@@ -567,6 +567,12 @@ private void do_testGetContent_gzipEncoding_finishReading(String contentEncoding
  ) {
  zipStream.write(dataToCompress);
  zipStream.close();
+
+ // GZIPInputStream uses a default buffer of 512B. Add enough content to exceed this
+ // limit, so that some content will be left in the connection.
+ for (int i = 0; i < 1024; i++) {
+ byteStream.write('7');
+ }
  mockBytes = byteStream.toByteArray();
  }
  final MockLowLevelHttpResponse mockResponse = new MockLowLevelHttpResponse();
@@ -594,6 +600,8 @@ public LowLevelHttpResponse execute() throws IOException {
  assertFalse(output.isClosed());
  assertEquals("abcd", response.parseAsString());
  assertTrue(output.isClosed());
+ // The underlying stream should be fully consumed, even if gzip only returns some of it.
+ assertEquals(-1, output.read());
  }
  }