Fixed dangling 'StkId' in 'luaV_finishget'
Bug introduced in 05932567.
diff --git a/lobject.h b/lobject.h
index b42539c..169512f 100644
--- a/lobject.h
+++ b/lobject.h
@@ -256,6 +256,8 @@
#define l_isfalse(o) (ttisfalse(o) || ttisnil(o))
+#define tagisfalse(t) ((t) == LUA_VFALSE || novariant(t) == LUA_TNIL)
+
#define setbfvalue(obj) settt_(obj, LUA_VFALSE)
diff --git a/ltm.c b/ltm.c
index c28f912..236f3bb 100644
--- a/ltm.c
+++ b/ltm.c
@@ -116,8 +116,8 @@
}
-void luaT_callTMres (lua_State *L, const TValue *f, const TValue *p1,
- const TValue *p2, StkId res) {
+int luaT_callTMres (lua_State *L, const TValue *f, const TValue *p1,
+ const TValue *p2, StkId res) {
ptrdiff_t result = savestack(L, res);
StkId func = L->top.p;
setobj2s(L, func, f); /* push function (assume EXTRA_STACK) */
@@ -131,6 +131,7 @@
luaD_callnoyield(L, func, 1);
res = restorestack(L, result);
setobjs2s(L, res, --L->top.p); /* move result to its place */
+ return ttypetag(s2v(res)); /* return tag of the result */
}
@@ -139,15 +140,16 @@
const TValue *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */
if (notm(tm))
tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
- if (notm(tm)) return 0;
- luaT_callTMres(L, tm, p1, p2, res);
- return 1;
+ if (notm(tm))
+ return -1; /* tag method not found */
+ else /* call tag method and return the tag of the result */
+ return luaT_callTMres(L, tm, p1, p2, res);
}
void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2,
StkId res, TMS event) {
- if (l_unlikely(!callbinTM(L, p1, p2, res, event))) {
+ if (l_unlikely(callbinTM(L, p1, p2, res, event) < 0)) {
switch (event) {
case TM_BAND: case TM_BOR: case TM_BXOR:
case TM_SHL: case TM_SHR: case TM_BNOT: {
@@ -164,11 +166,14 @@
}
+/*
+** The use of 'p1' after 'callbinTM' is safe because, when a tag
+** method is not found, 'callbinTM' cannot change the stack.
+*/
void luaT_tryconcatTM (lua_State *L) {
- StkId top = L->top.p;
- if (l_unlikely(!callbinTM(L, s2v(top - 2), s2v(top - 1), top - 2,
- TM_CONCAT)))
- luaG_concaterror(L, s2v(top - 2), s2v(top - 1));
+ StkId p1 = L->top.p - 2; /* first argument */
+ if (l_unlikely(callbinTM(L, s2v(p1), s2v(p1 + 1), p1, TM_CONCAT) < 0))
+ luaG_concaterror(L, s2v(p1), s2v(p1 + 1));
}
@@ -200,17 +205,17 @@
*/
int luaT_callorderTM (lua_State *L, const TValue *p1, const TValue *p2,
TMS event) {
- if (callbinTM(L, p1, p2, L->top.p, event)) /* try original event */
- return !l_isfalse(s2v(L->top.p));
+ int tag = callbinTM(L, p1, p2, L->top.p, event); /* try original event */
+ if (tag >= 0) /* found tag method? */
+ return !tagisfalse(tag);
#if defined(LUA_COMPAT_LT_LE)
else if (event == TM_LE) {
- /* try '!(p2 < p1)' for '(p1 <= p2)' */
- L->ci->callstatus |= CIST_LEQ; /* mark it is doing 'lt' for 'le' */
- if (callbinTM(L, p2, p1, L->top.p, TM_LT)) {
- L->ci->callstatus ^= CIST_LEQ; /* clear mark */
- return l_isfalse(s2v(L->top.p));
- }
- /* else error will remove this 'ci'; no need to clear mark */
+ /* try '!(p2 < p1)' for '(p1 <= p2)' */
+ L->ci->callstatus |= CIST_LEQ; /* mark it is doing 'lt' for 'le' */
+ tag = callbinTM(L, p2, p1, L->top.p, TM_LT);
+ L->ci->callstatus ^= CIST_LEQ; /* clear mark */
+ if (tag >= 0) /* found tag method? */
+ return tagisfalse(tag);
}
#endif
luaG_ordererror(L, p1, p2); /* no metamethod found */
diff --git a/ltm.h b/ltm.h
index 3c49713..df05b74 100644
--- a/ltm.h
+++ b/ltm.h
@@ -81,8 +81,8 @@
LUAI_FUNC void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1,
const TValue *p2, const TValue *p3);
-LUAI_FUNC void luaT_callTMres (lua_State *L, const TValue *f,
- const TValue *p1, const TValue *p2, StkId p3);
+LUAI_FUNC int luaT_callTMres (lua_State *L, const TValue *f,
+ const TValue *p1, const TValue *p2, StkId p3);
LUAI_FUNC void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2,
StkId res, TMS event);
LUAI_FUNC void luaT_tryconcatTM (lua_State *L);
diff --git a/lvm.c b/lvm.c
index cfa9961..37023af 100644
--- a/lvm.c
+++ b/lvm.c
@@ -308,8 +308,8 @@
/* else will try the metamethod */
}
if (ttisfunction(tm)) { /* is metamethod a function? */
- luaT_callTMres(L, tm, t, key, val); /* call it */
- return ttypetag(s2v(val));
+ tag = luaT_callTMres(L, tm, t, key, val); /* call it */
+ return tag; /* return tag of the result */
}
t = tm; /* else try to access 'tm[key]' */
luaV_fastget(t, key, s2v(val), luaH_get, tag);
@@ -606,8 +606,8 @@
if (tm == NULL) /* no TM? */
return 0; /* objects are different */
else {
- luaT_callTMres(L, tm, t1, t2, L->top.p); /* call TM */
- return !l_isfalse(s2v(L->top.p));
+ int tag = luaT_callTMres(L, tm, t1, t2, L->top.p); /* call TM */
+ return !tagisfalse(tag);
}
}
@@ -914,7 +914,7 @@
/*
** Auxiliary function for arithmetic operations over floats and others
-** with two register operands.
+** with two operands.
*/
#define op_arithf_aux(L,v1,v2,fop) { \
lua_Number n1; lua_Number n2; \
diff --git a/testes/events.lua b/testes/events.lua
index 8d8563b..5360ac3 100644
--- a/testes/events.lua
+++ b/testes/events.lua
@@ -248,6 +248,15 @@
test(Op(1), Op(2), Op(3))
+do -- test nil as false
+ local x = setmetatable({12}, {__eq= function (a,b)
+ return a[1] == b[1] or nil
+ end})
+ assert(not (x == {20}))
+ assert(x == {12})
+end
+
+
-- test `partial order'
local function rawSet(x)
