tor/changes/bug6174

  o Major bugfixes:
    - When we mark a circuit as unusable for new circuits, have it
      continue to be unusable for new circuits even if MaxCircuitDirtiness
      is increased too much at the wrong time, or the system clock jumped
      backwards. Fix for bug 6174; bugfix on 0.0.2pre26.
Stop frobbing timestamp_dirty as our sole means to mark circuits unusable In a number of places, we decrement timestamp_dirty by MaxCircuitDirtiness in order to mark a stream as "unusable for any new connections. This pattern sucks for a few reasons: * It is nonobvious. * It is error-prone: decrementing 0 can be a bad choice indeed. * It really wants to have a function. It can also introduce bugs if the system time jumps backwards, or if MaxCircuitDirtiness is increased. So in this patch, I add an unusable_for_new_conns flag to origin_circuit_t, make it get checked everywhere it should (I looked for things that tested timestamp_dirty), and add a new function to frob it. For now, the new function does still frob timestamp_dirty (after checking for underflow and whatnot), in case I missed any cases that should be checking unusable_for_new_conns. Fixes bug 6174. We first used this pattern in 516ef41ac1fd26f338c, which I think was in 0.0.2pre26 (but it could have been 0.0.2pre27). 2013-02-20 00:29:17 +01:00			`o Major bugfixes:`
			`- When we mark a circuit as unusable for new circuits, have it`
			`continue to be unusable for new circuits even if MaxCircuitDirtiness`
			`is increased too much at the wrong time, or the system clock jumped`
			`backwards. Fix for bug 6174; bugfix on 0.0.2pre26.`