third_party/protobuf: update to upstream r371

third_party/protobuf/src/google/protobuf/io/gzip_stream.cc

Index: third_party/protobuf/src/google/protobuf/io/gzip_stream.cc
diff --git a/third_party/protobuf/src/google/protobuf/io/gzip_stream.cc b/third_party/protobuf/src/google/protobuf/io/gzip_stream.cc
index 84d277f48377939edb0f71f06e1339b90d6bf0f6..0f1ff872aa419a980fdd5813840552c12d96561b 100644
--- a/third_party/protobuf/src/google/protobuf/io/gzip_stream.cc
+++ b/third_party/protobuf/src/google/protobuf/io/gzip_stream.cc
@@ -73,6 +73,17 @@ GzipInputStream::~GzipInputStream() {
   zerror_ = inflateEnd(&zcontext_);
 }
 
+static inline int internalInflateInit2(
+    z_stream* zcontext, GzipInputStream::Format format) {
+  int windowBitsFormat = 0;
+  switch (format) {
+    case GzipInputStream::GZIP: windowBitsFormat = 16; break;
+    case GzipInputStream::AUTO: windowBitsFormat = 32; break;
+    case GzipInputStream::ZLIB: windowBitsFormat = 0; break;
+  }
+  return inflateInit2(zcontext, /* windowBits */15 | windowBitsFormat);
+}
+
 int GzipInputStream::Inflate(int flush) {
   if ((zerror_ == Z_OK) && (zcontext_.avail_out == 0)) {
     // previous inflate filled output buffer. don't change input params yet.
@@ -89,14 +100,7 @@ int GzipInputStream::Inflate(int flush) {
     zcontext_.next_in = static_cast<Bytef*>(const_cast<void*>(in));
     zcontext_.avail_in = in_size;
     if (first) {
-      int windowBitsFormat = 0;
-      switch (format_) {
-        case GZIP: windowBitsFormat = 16; break;
-        case AUTO: windowBitsFormat = 32; break;
-        case ZLIB: windowBitsFormat = 0; break;
-      }
-      int error = inflateInit2(&zcontext_,
-        /* windowBits */15 | windowBitsFormat);
+      int error = internalInflateInit2(&zcontext_, format_);
       if (error != Z_OK) {
         return error;
       }
@@ -127,9 +131,21 @@ bool GzipInputStream::Next(const void** data, int* size) {
     return true;
   }
   if (zerror_ == Z_STREAM_END) {
-    *data = NULL;
-    *size = 0;
-    return false;
+    if (zcontext_.next_out != NULL) {
+      // sub_stream_ may have concatenated streams to follow
+      zerror_ = inflateEnd(&zcontext_);
+      if (zerror_ != Z_OK) {
+        return false;
+      }
+      zerror_ = internalInflateInit2(&zcontext_, format_);
+      if (zerror_ != Z_OK) {
+        return false;
+      }
+    } else {
+      *data = NULL;
+      *size = 0;
+      return false;
+    }
   }
   zerror_ = Inflate(Z_NO_FLUSH);
   if ((zerror_ == Z_STREAM_END) && (zcontext_.next_out == NULL)) {
@@ -251,8 +267,7 @@ int GzipOutputStream::Deflate(int flush) {
     }
     error = deflate(&zcontext_, flush);
   } while (error == Z_OK && zcontext_.avail_out == 0);
-  if (((flush == Z_FULL_FLUSH) || (flush == Z_FINISH))
-      && (zcontext_.avail_out != sub_data_size_)) {
+  if ((flush == Z_FULL_FLUSH) || (flush == Z_FINISH)) {
     // Notify lower layer of data.
     sub_stream_->BackUp(zcontext_.avail_out);
     // We don't own the buffer anymore.