1 files changed, 36 insertions, 16 deletions

diff --git a/lgc.c b/lgc.c
index cada07d9..bbaa5ff7 100644
--- a/lgc.c
+++ b/lgc.c
@@ -126,7 +126,6 @@ static l_mem objsize (GCObject *o) {
       CClosure *cl = gco2ccl(o);
       res = sizeCclosure(cl->nupvalues);
       break;
-      break;
     }
     case LUA_VUSERDATA: {
       Udata *u = gco2u(o);
@@ -465,6 +464,8 @@ static void restartcollection (global_State *g) {
 ** TOUCHED1 objects need to be in the list. TOUCHED2 doesn't need to go
 ** back to a gray list, but then it must become OLD. (That is what
 ** 'correctgraylist' does when it finds a TOUCHED2 object.)
+** This function is a no-op in incremental mode, as objects cannot be
+** marked as touched in that mode.
 */
 static void genlink (global_State *g, GCObject *o) {
   lua_assert(isblack(o));
@@ -480,7 +481,8 @@ static void genlink (global_State *g, GCObject *o) {
 ** Traverse a table with weak values and link it to proper list. During
 ** propagate phase, keep it in 'grayagain' list, to be revisited in the
 ** atomic phase. In the atomic phase, if table has any white value,
-** put it in 'weak' list, to be cleared.
+** put it in 'weak' list, to be cleared; otherwise, call 'genlink'
+** to check table age in generational mode.
 */
 static void traverseweakvalue (global_State *g, Table *h) {
   Node *n, *limit = gnodelast(h);
@@ -501,6 +503,8 @@ static void traverseweakvalue (global_State *g, Table *h) {
     linkgclist(h, g->grayagain);  /* must retraverse it in atomic phase */
   else if (hasclears)
       linkgclist(h, g->weak);  /* has to be cleared later */
+  else
+    genlink(g, obj2gco(h));
 }
 
 
@@ -585,25 +589,41 @@ static void traversestrongtable (global_State *g, Table *h) {
 }
 
 
-static l_mem traversetable (global_State *g, Table *h) {
-  const char *weakkey, *weakvalue;
+/*
+** (result & 1) iff weak values; (result & 2) iff weak keys.
+*/
+static int getmode (global_State *g, Table *h) {
   const TValue *mode = gfasttm(g, h->metatable, TM_MODE);
-  TString *smode;
+  if (mode == NULL || !ttisshrstring(mode))
+    return 0;  /* ignore non-(short)string modes */
+  else {
+    const char *smode = getshrstr(tsvalue(mode));
+    const char *weakkey = strchr(smode, 'k');
+    const char *weakvalue = strchr(smode, 'v');
+    return ((weakkey != NULL) << 1) | (weakvalue != NULL);
+  }
+}
+
+
+static l_mem traversetable (global_State *g, Table *h) {
   markobjectN(g, h->metatable);
-  if (mode && ttisshrstring(mode) &&  /* is there a weak mode? */
-      (cast_void(smode = tsvalue(mode)),
-       cast_void(weakkey = strchr(getshrstr(smode), 'k')),
-       cast_void(weakvalue = strchr(getshrstr(smode), 'v')),
-       (weakkey || weakvalue))) {  /* is really weak? */
-    if (!weakkey)  /* strong keys? */
+  switch (getmode(g, h)) {
+    case 0:  /* not weak */
+      traversestrongtable(g, h);
+      break;
+    case 1:  /* weak values */
       traverseweakvalue(g, h);
-    else if (!weakvalue)  /* strong values? */
+      break;
+    case 2:  /* weak keys */
       traverseephemeron(g, h, 0);
-    else  /* all weak */
-      linkgclist(h, g->allweak);  /* nothing to traverse now */
+      break;
+    case 3:  /* all weak; nothing to traverse */
+      if (g->gcstate == GCSpropagate)
+        linkgclist(h, g->grayagain);  /* must visit again its metatable */
+      else
+        linkgclist(h, g->allweak);  /* must clear collected entries */
+      break;
   }
-  else  /* not weak */
-    traversestrongtable(g, h);
   return 1 + 2*sizenode(h) + h->asize;
 }