Delete pre-existing HTTP Header keys to avoid append #40
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If you re-use the
net/http
request object and passrequest.Header
to thetracer.Inject
function multiple times, values will actually get appended to already set headers.This is because the
TextMapWriter
interface in Go OpenTracing calls onlyhttp.Header.Add()
(as seen here) and the end implementation ofAdd()
inhttp.Header
states It appends to any existing values associated with key.This PR checks for and deletes any pre-existing keys on
Inject
.Thanks @vetinari for the heads up and a test to demonstrate.