fix: avoid attaching botched content-length header#136
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Before this commit, `#{<<"content-length">> => 0}` attached to
response headers of body-less reponses can cause literal NULL
byte to appear in the response stream as part of this header.
This was possible because header-value was fed into a stream
verbatim, and sub-256 integer is a valid piece of `iodata()`.
E.g. in `cow_http1`:
```
headers(Headers) ->
[[N, <<": ">>, V, <<"\r\n">>] || {N, V} <- Headers]
```
thalesmg
reviewed
Mar 30, 2026
thalesmg
approved these changes
Mar 30, 2026
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Before this commit,
#{<<"content-length">> => 0}attached to response headers of body-less reponses can cause literal NULL byte to appear in the response stream as part of this header.This was possible because header-value was fed into a stream verbatim, and sub-256 integer is a valid piece of
iodata().E.g. in
cow_http1, as part ofcowboy_http:commands/3->cow_http:response/3->cow_http1:response/3call chain: