Description:
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A script we use enabling users to download uploaded files from the webserver uses readfile() to accomplish this task.

At 2.000.000 bytes the script always stops sending output without any mention in any logs.

The behaviour started after upgrading from 5.0.3 to 5.0.4.

The system runs with default memory limit (not compiled with --enable-memory-limit) And changelog says nothing on this possible change of behaviour.

We do not use the outputbuffering system
We use session_start (as i have seen bugs reported on this earlier)

Reproduce code:
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readfile(file larger than 2.000.000 bytes)


Expected result:
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whole filecontent outputted.
Or some error if hitting some undocumented memorylimit

Actual result:
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In browser:

no result.
no file downloaded
no messages to user or to server
server stops sending, but client doesn't honor that

Using wget:
a 2.000.000 byte truncated file