Fix lua_checkstack to check against LUAI_MAXSTACK. Adds luaD_growstack and luaD_reallocstack

1 files changed, 13 insertions, 1 deletions

diff --git a/src/lapi.js b/src/lapi.js
index cea0568..79c666c 100644
--- a/src/lapi.js
+++ b/src/lapi.js
@@ -91,8 +91,20 @@ const index2addr_ = function(L, idx) {
 };
 
 const lua_checkstack = function(L, n) {
+    let res;
     let ci = L.ci;
-    let res = L.stack.length < luaconf.LUAI_MAXSTACK;
+    assert(n >= 0, "negative 'n'");
+    if (L.stack.length - L.top > n) /* stack large enough? */
+        res = true;
+    else { /* no; need to grow stack */
+        let inuse = L.top + lstate.EXTRA_STACK;
+        if (inuse > luaconf.LUAI_MAXSTACK - n)  /* can grow without overflow? */
+            res = false;  /* no */
+        else { /* try to grow stack */
+            ldo.luaD_growstack(L, n);
+            res = true;
+        }
+    }
 
     if (res && ci.top < L.top + n)
         ci.top = L.top + n;  /* adjust frame top */