Working on the integration test suite for c_glib exposed a problem with ThriftFramedTransport: If the peer closes the connection unexpectedly, thrift_framed_transport_read_frame will fail with either a critical GLib warning or a segmentation fault.
The attached patches fix this issue. The changes are, in order:
1. Add a suitable test case to testframedtransport.c.
2. Modify thrift_framed_transport_read_frame and thrift_framed_transport_read_frame_slow so they check for and respond to errors returned from other Thrift methods. Additionally, thrift_framed_transport_read_frame_slow should now always return -1 in case of read error, which includes "successfully" reading zero bytes from the peer (which generally indicates a prematurely closed connection).
I've also taken the liberty of gently rewriting thrift_framed_transport_read_frame so it
- Correctly uses an unsigned integer variable to hold the frame's size,
- Uses thrift_transport_... functions to invoke class methods instead of the rather brittle practice of dereferencing class members directly, and
- Accurately reports success or failure.