Fixed misleading error text on TCP connect timeout - #155
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When poll()/select() reports a timeout while waiting for a non-blocking connect() to complete, requestAssociationTCP() appended the last network error code to the condition text. No error code has been set in that case, so the text was that of error code 0, resulting in messages like TCP Initialization Error: Success (Timeout) on POSIX platforms, or "No error (Timeout)" on Windows, which reads as both a failure and a success at the same time. Report the timeout on its own instead. This complements the fix in the rc < 0 branch (GitHub PR DCMTK#129), which caches the error code before it is reset by close()/closesocket().
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Problem
When a connection attempt times out,
requestAssociationTCP()produces a condition text thatclaims both failure and success at the same time:
(macOS/Linux; on Windows the same path yields
No error (Timeout).)In
dcmnet/libsrc/dulfsm.cc, the non-blockingconnect()is awaited withpoll()/select().A return value of
0means timeout, not error — no error code has been set — but the timeoutbranch appended
OFStandard::getLastNetworkErrorCode().message()anyway, which renders errorcode 0 as
"Success"/"No error".This is the sibling of #129, which fixed the
rc < 0branch by caching the error code beforeclose()/closesocket()resets it. That fix is inmaster; therc == 0timeout branch stillreports error code 0.
Fix
Drop the error-code text from the timeout branch and report the timeout on its own:
One-line change plus a comment explaining why no error code is reported there.
Reproducing
Any SCU with a connect timeout set (
DcmSCU::setConnectionTimeout()) against an unreachablehost that silently drops SYN, e.g.:
A host that actively refuses gets
ECONNREFUSEDvia thegetsockopt(SO_ERROR)branch, so thebogus text only shows on a genuine timeout.
Observed with 3.6.9 and reproducible on current
master; the affected lines are unchangedin 3.7.0.