nodejs/node · info

extra input\n

Error message

extra input\n

What it means

Informational verbose message at brotli.c:1267, printed only when verbosity > 0 AND context->allow_concatenated is true. After a brotli stream decodes successfully (BROTLI_DECODER_RESULT_SUCCESS), if there are still bytes remaining in the file, the tool treats this as a concatenated multi-stream brotli file. It destroys the current decoder, creates a fresh one via InitDecoder, and continues decoding the next stream. This message is not an error — it signals normal concatenated-stream processing.

Source

Thrown at deps/brotli/c/tools/brotli.c:1267

    } else if (result == BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT) {
      if (!ProvideOutput(context)) return BROTLI_FALSE;
    } else if (result == BROTLI_DECODER_RESULT_SUCCESS) {
      if (!FlushOutput(context)) return BROTLI_FALSE;
      BROTLI_BOOL has_more_input = (context->available_in != 0);
      int extra_char = EOF;
      if (!has_more_input) {
        extra_char = fgetc(context->fin);
        if (extra_char != EOF) {
          has_more_input = BROTLI_TRUE;
          context->input[0] = (uint8_t)extra_char;
          context->next_in = context->input;
          context->available_in = 1;
        }
      }
      if (has_more_input) {
        if (context->allow_concatenated) {
          if (context->verbosity > 0) {
            fprintf(stderr, "extra input\n");
          }
          if (!ProvideOutput(context)) return BROTLI_FALSE;
          BrotliDecoderDestroyInstance(context->decoder);
          context->decoder = NULL;
          if (!InitDecoder(context)) return BROTLI_FALSE;
          s = context->decoder;
        } else {
          fprintf(stderr, "corrupt input [%s]\n",
                  PrintablePath(context->current_input_path));
          if (context->verbosity > 0) {
            fprintf(stderr, "reason: extra input\n");
          }
          return BROTLI_FALSE;
        }
      } else {
        if (context->verbosity > 0) {
          context->end_time = clock();
          fprintf(stderr, "Decompressed ");

View on GitHub (pinned to 1b2de5e052)

Solutions

1. No action needed — this is expected behavior when decompressing concatenated brotli streams with -v enabled.
2. If the message is noisy, run without -v to suppress it.
3. If you did not expect concatenated streams, investigate whether the source inadvertently appended multiple brotli files together.

// This is informational, not an error. No validation needed.
// If you want to detect concatenated streams programmatically:
// after BrotliDecoderResult SUCCESS, check if fgetc(fin) != EOF.

When it happens

Trigger: Decompressing a file that contains two or more brotli streams concatenated back-to-back (a valid brotli convention). After the first stream reaches SUCCESS, the code peeks one extra byte with fgetc; if it is not EOF, has_more_input is set. With allow_concatenated enabled (the default for the brotli -d command), the tool logs this message and reinitializes the decoder for the next stream.

Common situations: Decompressing a file produced by concatenating multiple brotli-compressed chunks (common in web bundling, CDNI, or streaming compression pipelines). A developer runs 'brotli -d -v multi.br' and sees this informational line for each concatenated segment.

Related errors

• reason: comment mismatch\n
• reason: truncated input\n
• reason: extra input\n
• empty output file name for [%s] input file\n
• input file [%s] suffix mismatch\n

AI-assisted analysis of nodejs/node@1b2de5e052 (2026-08-13). Data as JSON: /api/errors/ca1926e74056a55b. Report an issue: GitHub.