'coroutine.close'/'lua_resetthread' report original errors

Besides errors in closing methods, 'coroutine.close' and
'lua_resetthread' also consider the original error that stopped the
thread, if any.

testes/coroutine.lua

@@ -134,7 +134,8 @@ do
   local co = coroutine.create(print)
   assert(coroutine.resume(co, "testing 'coroutine.close'"))
   assert(coroutine.status(co) == "dead")
-  assert(coroutine.close(co))
+  local st, msg = coroutine.close(co)
+  assert(st and msg == nil)
 
   -- cannot close the running coroutine
   local st, msg = pcall(coroutine.close, coroutine.running())
@@ -151,6 +152,13 @@ do
   -- to-be-closed variables in coroutines
   local X
 
+  -- closing a coroutine after an error
+  local co = coroutine.create(error)
+  local st, msg = coroutine.resume(co, 100)
+  assert(not st and msg == 100)
+  st, msg = coroutine.close(co)
+  assert(not st and msg == 100)
+
   co = coroutine.create(function ()
     local x <close> = func2close(function (self, err)
       assert(err == nil); X = false

testes/cstack.lua

@@ -135,14 +135,18 @@ if T then
   local topB, sizeB   -- top and size Before overflow
   local topA, sizeA   -- top and size After overflow
   topB, sizeB = T.stacklevel()
+  collectgarbage("stop")    -- __gc should not be called with a full stack
   xpcall(f, err)
+  collectgarbage("restart")
   topA, sizeA = T.stacklevel()
   -- sizes should be comparable
   assert(topA == topB and sizeA < sizeB * 2)
   print(string.format("maximum stack size: %d", stack1))
   LIM = N      -- will stop recursion at maximum level
   N = 0        -- to count again
+  collectgarbage("stop")    -- __gc should not be called with a full stack
   f()
+  collectgarbage("restart")
   print"+"
 end
 

testes/locals.lua

@@ -362,7 +362,7 @@ end
 
 local function checkwarn (msg)
   if T then
-    assert(string.find(_WARN, msg))
+    assert(_WARN and string.find(_WARN, msg))
     _WARN = false    -- reset variable to check next warning
   end
 end
@@ -670,10 +670,13 @@ do
   -- error in a wrapped coroutine raising errors when closing a variable
   local x = 0
   local co = coroutine.wrap(function ()
-    local xx <close> = func2close(function () x = x + 1; error("@YYY") end)
+    local xx <close> = func2close(function ()
+      x = x + 1;
+      checkwarn("@XXX"); error("@YYY")
+    end)
     local xv <close> = func2close(function () x = x + 1; error("@XXX") end)
-      coroutine.yield(100)
-      error(200)
+    coroutine.yield(100)
+    error(200)
   end)
   assert(co() == 100); assert(x == 0)
   local st, msg = pcall(co); assert(x == 2)
@@ -683,10 +686,14 @@ do
   local x = 0
   local y = 0
   co = coroutine.wrap(function ()
-    local xx <close> = func2close(function () y = y + 1; error("YYY") end)
-    local xv <close> = func2close(function () x = x + 1; error("XXX") end)
-      coroutine.yield(100)
-      return 200
+    local xx <close> = func2close(function ()
+      y = y + 1; checkwarn("XXX"); error("YYY")
+    end)
+    local xv <close> = func2close(function ()
+      x = x + 1; error("XXX")
+    end)
+    coroutine.yield(100)
+    return 200
   end)
   assert(co() == 100); assert(x == 0)
   local st, msg = pcall(co)