* anders/diameter/SoC/OTP-10688: Add RFC 6733 commentary to SoC chapter Add RFC 6737 Capabilities Update dictionary Remove cruft from doc Makefile
Although it's neither built nor supported in code yet.
Also add comments to identify the corresponding OTP releases. Purposely don't use regexp version numbers to be explicit about previously released versions. (Could use them in one direction but then app suite needs to be adapted.)
Add a 'strict' target to compile with -Werror and fix a dependency. Reorder test suites alphabetically. The two suites that currently take the longest to run conveniently come last.
The workaround (commit 57d5564f) was to dialyzer only understanding nowarn_unused_function on individual functions. This is no longer the case as of R15B01 (commit 477fd95a).
RFC 3588 allowed only 3xxx result codes in an answer-message (that is,
an answer that sets the E-bit) while RFC 6733 also allows 5xxx result
codes. Setting request_errors = answer tells diameter to answer 5xxx
errors itself. Returning {answer_message, integer()} from a
handle_request callback allows both 3xxx and 5xxx result codes to be
set. {protocol_error, integer()} is retained for 3xxx result codes.
In particular, don't put an error tuple in the errors field of
a #diameter_packet{} when Result-Code and the E-bit are in conflict, put
{integer(), #diameter_avp{}}.
When receiving a request for which errors have been detected during decode, diameter previously used the errors list in the decoded diameter_packet record to unconditionally set Result-Code and Failed-AVP in the outgoing answer. It wasn't particularly delicate in doing so however and would happily set a 5xxx Result-Code even if a handle_request callback returned an answer-message, leading to an encode error. This behaviour became even less endearing as of commit ac452e28, which made it possible to handle_request to take place even for protocol errors. (ie. When a callback typically should return an answer-message.) This commit fixes the behaviour by only setting a value that's appropriate for the answer in question, either a 3xxx or a 5xxx, depending on if the answer's an answer-message or not. It also allows handle_request to prevent diameter from setting anything by setting errors = false in a returned diameter_packet. Ideally it should have been errors = [] but the empty list is the default value for the errors field and changing the default (ideally there shouldn't have been one) would require recompilation of all modules including diameter.hrl: choose the less attractive 'false' to avoid such backwards incompatibility. The request reception is also refactored somewhat to shorten some call chains.
Configuring the value 'callback' all errors detected in incoming requests to result in a handle_request callback. The default value 'answer_3xxx' is the previous behaviour in which diameter answers protocol errors without a callback.