René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"ungzipping buffer with trailing garbage throws error","articleBody":"One site sends a gzipped html page and I try to ungzip page for further processing but zlib throws error `incorrect header check`. Error happens due to extra data after gzipped page. Yes, gzipped data is not valid, since have trailing data, but in other hand, browser eat that normally.\n\nMinimal example:\n\n``` javascript\nvar zlib = require('zlib')\n\n// from test-zlib-from-gzip-with-trailing-garbage.js\nbufOk = Buffer.concat([\n    zlib.gzipSync(\"abc\"),\n    Buffer(10).fill(0)\n]);\n\nbufWrong = Buffer.concat([\n    zlib.gzipSync(\"abc\"),\n    Buffer(\"\\n \\n\\n\\n\\n \\n\")\n]);\n\n// wil not raise Error\nconsole.log(\"bufOk:\", zlib.gunzipSync(bufOk).toString());\n\n// will raise Error('incorrect header check')\nconsole.log(\"bufWrong:\", zlib.gunzipSync(bufWrong).toString());\n```\n\nAlso live example:\n\n``` javascript\nvar req = require('request')\nreq.get('http://irsural.ru', {gzip: true}, (err, res, body) =\u003e {\n    if (err != null) {\n        console.log('Error:', err);\n        return \n    }\n    console.log(body);\n});\n```\n\nIn other languages (for example, python - [requests](https://github.com/kennethreitz/requests/blob/efb4af01271c8c0ddf49457c7096a5bc91edbdad/requests/packages/urllib3/response.py#L50)) I can set `windowBits` to `16 + zlib.Z_MAX_WINDOWBITS` but `node` strictly restricted `windowBits` from 0 to 15 even in addon.\n## \n- **Version**: v6.2.2\n- **Platform**: linux, x86_64\n- **Subsystem**: zlib\n","author":{"url":"https://github.com/horpto","@type":"Person","name":"horpto"},"datePublished":"2016-06-30T16:38:49.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/7502/node/issues/7502"}