Pipe write operations across a network are limited to 65,535 bytes per write.

Pipe write operations across a network are limited to 65,535 bytes per write. For more information regarding pipes, see the Remarks section.

Source: WriteFileEx function

I managed to run into exactly that limit today. Patch follows.

Symptom is that

• the writing end acts as if it had written all the bytes (in fact, it did)
• but the remainder of ~ 65535 bytes is just lost somewhere and never reaches the reading end

Consequently, the process at the reading end of the pipe gets stuck while waiting for the remaining bytes.