Allow disabling padding

lib/includes/nghttp2/nghttp2.h

@@ -1338,8 +1338,7 @@ typedef enum {
    * payload. If this option is set to N, padding is added to frame
    * payload so that its payload length is divisible by N. For DATA
    * frame, due to flow control, padding is not always added according
-   * to this alignment. The option value must be greater than or equal
-   * to 8.
+   * to this alignment. Specifying 0 to this option disables padding.
    */
   NGHTTP2_OPT_PADDING_BOUNDARY = 1 << 3
 } nghttp2_opt;

lib/nghttp2_session.c

@@ -224,8 +224,7 @@ static int nghttp2_session_new(nghttp2_session **session_ptr,
     (*session_ptr)->opt_flags |=
       NGHTTP2_OPTMASK_NO_AUTO_CONNECTION_WINDOW_UPDATE;
   }
-  if((opt_set_mask & NGHTTP2_OPT_PADDING_BOUNDARY) &&
-     opt_set->padding_boundary >= 8) {
+  if(opt_set_mask & NGHTTP2_OPT_PADDING_BOUNDARY) {
     (*session_ptr)->padding_boundary = opt_set->padding_boundary;
   } else {
     (*session_ptr)->padding_boundary = NGHTTP2_PADDING_BOUNDARY;

src/nghttp.cc

@@ -1711,7 +1711,8 @@ void print_help(std::ostream& out)
       << "    -c, --header-table-size=<N>\n"
       << "                       Specify decoder header table size.\n"
       << "    -b, --padding=<BOUNDARY>\n"
-      << "                       Padding boundary for frame payload.\n"
+      << "                       Padding boundary for frame payload. Specify\n"
+      << "                       0 to disable padding.\n"
       << "    --color            Force colored log output.\n"
       << "    --continuation     Send large header to test CONTINUATION.\n"
       << std::endl;

src/nghttpd.cc

@@ -116,7 +116,8 @@ void print_help(std::ostream& out)
       << "                       PATH and PUSH_PATHs are relative to document\n"
       << "                       root. See --htdocs option.\n"
       << "    -b, --padding=<BOUNDARY>\n"
-      << "                       Padding boundary for frame payload.\n"
+      << "                       Padding boundary for frame payload. Specify\n"
+      << "                       0 to disable padding.\n"
       << "    -h, --help         Print this help.\n"
       << std::endl;
 }