Throw an exception instead of trying to transmit a header frame that exceeds max frame size

[ibolotin]

Proposed Changes

Addresses issue #362
Instead of trying to transmit header frame that exceeds max frame size (that results in server shutdown of connection with frame_too_large error and breaks all open channels) - throw IllegalArgumentException stating that "Content headers exceeded max frame size"

Types of Changes

• Bugfix (non-breaking change which fixes issue Throw an exception instead of trying to transmit a header frame that exceeds max frame size #362)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation (correction or otherwise)
• Cosmetics (whitespace, appearance)

Checklist

• I have read the CONTRIBUTING.md document
• I have signed the CA (see https://cla.pivotal.io/sign/rabbitmq)
• All tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in related repositories

[ibolotin]

moved this code down to after size check to avoid leaving channel in invalid state in case exception was thrown

[michaelklishin]

This looks reasonable. I'll wait for @acogoluegnes' review before merging.

[acogoluegnes]

@ibolotin Thanks!