Change lane:join() return values

* when no error is raised in the lane, lane:join() now precedes the lane returned values with true
* lane body is no longer forced to return something when used with join()
* adjusted all relevant unit tests accordingly

1 files changed, 3 insertions, 2 deletions

diff --git a/unit_tests/scripts/linda/wake_period.lua b/unit_tests/scripts/linda/wake_period.lua
index e4a900d..d2dccc3 100644
--- a/unit_tests/scripts/linda/wake_period.lua
+++ b/unit_tests/scripts/linda/wake_period.lua
@@ -6,7 +6,7 @@ local lanes = require_lanes_result_1
 local body = function(linda_)
         -- a blocking read that lasts longer than the tested wake_period values
         linda_:receive(2, "empty_slot")
-        return true
+        return "done"
 end
 
 -- if we don't cancel the lane, we should wait the whole duration
@@ -22,7 +22,8 @@ local function check_wake_duration(linda_, expected_, do_cancel_)
                 assert(result == false and reason == 'timeout', "unexpected cancel result")
         end
         -- this should wait until the linda wakes by itself before the actual receive timeout and sees the cancel request
-        h:join()
+        local r, ret = h:join()
+        assert(r == true and ret == "done")
         local t1 = lanes.now_secs()
         local delta = t1 - t0
         -- the linda should check for cancellation at about the expected period, not earlier