Clear the destination HTTPValue before trying to write it.

Author: jmarantz

net/instaweb/http/inflating_fetch.cc

@@ -122,6 +122,7 @@ bool InflatingFetch::UnGzipValueIfCompressed(const HTTPValue& src,
       headers->Remove(HttpAttributes::kContentEncoding, HttpAttributes::kGzip);
       headers->SetContentLength(inflated.length());
       content.set(inflated.c_str(), inflated.length());
+      dest->Clear();
       dest->Write(content, handler);
       dest->SetHeaders(headers);
       return true;

net/instaweb/http/inflating_fetch_test.cc

@@ -326,6 +326,9 @@ TEST(StaticInflatingFetchTest, CompressUncompressValue) {
                headers.Lookup1(HttpAttributes::kContentEncoding));
   compressed_value.ExtractHeaders(&headers, &handler);
   HTTPValue uncompressed_value;
+  ResponseHeaders temp_headers;
+  temp_headers.Add("a", "b");
+  uncompressed_value.SetHeaders(&temp_headers);
   ASSERT_TRUE(InflatingFetch::UnGzipValueIfCompressed(
       compressed_value, &headers, &uncompressed_value, &handler));
   uncompressed_value.ExtractContents(&contents);