Dubiously correct code in header_rewrite plugin.

[ywkaras]

This seems like it would cause a duplicate call to TSHttpTxnReenable() (since it's call in an operator exec() function).

trafficserver/plugins/header_rewrite/operators.cc

Line 537 in e31eca4

TSHttpTxnReenable(res.txnp, TS_EVENT_HTTP_CONTINUE);

This continuation function runs on transaction hooks, but it does not call TSHttpTxnReenable():

trafficserver/plugins/header_rewrite/operators.cc

Line 434 in e31eca4

cont_add_location(TSCont contp, TSEvent event, void *edata)

[ywkaras]

This is the pull request that introduced the code in question: #2495