In quic, return from quiccryptostream::writependingcryptoretransmission after partial writes. protected by gfe2_reloadable_flag_quic_fix_write_pending_crypto_retransmission.

Also add more logging when failed to serialize packet.

PiperOrigin-RevId: 311754483
Change-Id: I928ef099e00a6029386440339704cd15f9d1db22

quic/core/quic_crypto_stream.cc

diff --git a/quic/core/quic_crypto_stream.cc b/quic/core/quic_crypto_stream.cc
index 20704fb..59a0122 100644
--- a/quic/core/quic_crypto_stream.cc
+++ b/quic/core/quic_crypto_stream.cc
@@ -268,6 +268,12 @@
           level, pending.length, pending.offset, HANDSHAKE_RETRANSMISSION);
       send_buffer->OnStreamDataRetransmitted(pending.offset, bytes_consumed);
       if (bytes_consumed < pending.length) {
+        if (GetQuicReloadableFlag(
+                quic_fix_write_pending_crypto_retransmission)) {
+          QUIC_RELOADABLE_FLAG_COUNT(
+              quic_fix_write_pending_crypto_retransmission);
+          return;
+        }
         break;
       }
     }

quic/core/quic_packet_creator.cc

diff --git a/quic/core/quic_packet_creator.cc b/quic/core/quic_packet_creator.cc
index 0ae78d2..d5555fc 100644
--- a/quic/core/quic_packet_creator.cc
+++ b/quic/core/quic_packet_creator.cc
@@ -722,7 +722,12 @@
       framer_->BuildDataPacket(header, queued_frames_, encrypted_buffer,
                                packet_size_, packet_.encryption_level);
   if (length == 0) {
-    QUIC_BUG << "Failed to serialize " << queued_frames_.size() << " frames.";
+    QUIC_BUG << "Failed to serialize " << QuicFramesToString(queued_frames_)
+             << " at encryption_level: "
+             << EncryptionLevelToString(packet_.encryption_level)
+             << ", needs_full_padding_: " << needs_full_padding_
+             << ", packet_.num_padding_bytes: " << packet_.num_padding_bytes
+             << ", pending_padding_bytes_: " << pending_padding_bytes_;
     return;
   }
 
@@ -1291,7 +1296,8 @@
       // The only pending data in the packet is non-retransmittable frames. I'm
       // assuming here that they won't occupy so much of the packet that a
       // CRYPTO frame won't fit.
-      QUIC_BUG << "Failed to ConsumeCryptoData at level " << level;
+      QUIC_BUG << "Failed to ConsumeCryptoData at level "
+               << EncryptionLevelToString(level);
       return 0;
     }
     total_bytes_consumed += frame.crypto_frame->data_length;