3 files changed, 11 insertions, 6 deletions

diff --git a/ldebug.c b/ldebug.c
index b1f16ac9..d6f132ea 100644
--- a/ldebug.c
+++ b/ldebug.c
@@ -925,12 +925,12 @@ int luaG_traceexec (lua_State *L, const Instruction *pc) {
   }
   pc++;  /* reference is always next instruction */
   ci->u.l.savedpc = pc;  /* save 'pc' */
-  counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT));
+  counthook = (mask & LUA_MASKCOUNT) && (--L->hookcount == 0);
   if (counthook)
     resethookcount(L);  /* reset count */
   else if (!(mask & LUA_MASKLINE))
     return 1;  /* no line hook and count != 0; nothing to be done now */
-  if (ci->callstatus & CIST_HOOKYIELD) {  /* called hook last time? */
+  if (ci->callstatus & CIST_HOOKYIELD) {  /* hook yielded last time? */
     ci->callstatus &= ~CIST_HOOKYIELD;  /* erase mark */
     return 1;  /* do not call hook again (VM yielded, so it did not move) */
   }
@@ -952,7 +952,6 @@ int luaG_traceexec (lua_State *L, const Instruction *pc) {
   if (L->status == LUA_YIELD) {  /* did hook yield? */
     if (counthook)
       L->hookcount = 1;  /* undo decrement to zero */
-    ci->u.l.savedpc--;  /* undo increment (resume will increment it again) */
     ci->callstatus |= CIST_HOOKYIELD;  /* mark that it yielded */
     luaD_throw(L, LUA_YIELD);
   }
diff --git a/ldo.c b/ldo.c
index bd8d965f..ea052950 100644
--- a/ldo.c
+++ b/ldo.c
@@ -792,6 +792,10 @@ static void resume (lua_State *L, void *ud) {
     lua_assert(L->status == LUA_YIELD);
     L->status = LUA_OK;  /* mark that it is running (again) */
     if (isLua(ci)) {  /* yielded inside a hook? */
+      /* undo increment made by 'luaG_traceexec': instruction was not
+         executed yet */
+      lua_assert(ci->callstatus & CIST_HOOKYIELD);
+      ci->u.l.savedpc--;
       L->top.p = firstArg;  /* discard arguments */
       luaV_execute(L, ci);  /* just continue running Lua code */
     }
diff --git a/testes/coroutine.lua b/testes/coroutine.lua
index de7e46fb..e566c86e 100644
--- a/testes/coroutine.lua
+++ b/testes/coroutine.lua
@@ -610,18 +610,20 @@ else
     -- (bug in 5.2/5.3)
     c = coroutine.create(function (a, ...)
       T.sethook("yield 0", "l")   -- will yield on next two lines
-      assert(a == 10)
+      local b = a
       return ...
     end)
 
     assert(coroutine.resume(c, 1, 2, 3))   -- start coroutine
     local n,v = debug.getlocal(c, 0, 1)    -- check its local
-    assert(n == "a" and v == 1)
+    assert(n == "a" and v == 1 and debug.getlocal(c, 0, 2) ~= "b")
     assert(debug.setlocal(c, 0, 1, 10))     -- test 'setlocal'
     local t = debug.getinfo(c, 0)        -- test 'getinfo'
-    assert(t.currentline == t.linedefined + 1)
+    assert(t.currentline == t.linedefined + 2)
     assert(not debug.getinfo(c, 1))      -- no other level
     assert(coroutine.resume(c))          -- run next line
+    local n,v = debug.getlocal(c, 0, 2)    -- check next local
+    assert(n == "b" and v == 10)
     v = {coroutine.resume(c)}         -- finish coroutine
     assert(v[1] == true and v[2] == 2 and v[3] == 3 and v[4] == undef)
     assert(not coroutine.resume(c))