Description:
See bug #29245 for background.
We need a tool to enforce cross-version compatibility in error numbers. Any error code which is defined in multiple versions must have the same value in all versions (except for ER_ERROR_LAST, which obviously will differ across versions).
A tool, either in the source tree itself (best, but perhaps too restrictive), or in PushBuild, must check this and disallow changes which break it (or complain very loudly if such a change does make it into the code).
How to repeat:
See bug #29245. For the correct method of adding error messages, see http://forge.mysql.com/wiki/MySQL_Internals_Error_Messages#Adding_an_error_message_in_mult...
Suggested fix:
Perhaps abi_check can be used for this purpose; however, we need to be able to add error messages in the proper way without causing a headache.