src/loslib.js: Fix os.time() with out-of-range values

Fixes #126

2 files changed, 35 insertions, 10 deletions

diff --git a/src/loslib.js b/src/loslib.js
index 6c6b2f4..814d1b2 100644
--- a/src/loslib.js
+++ b/src/loslib.js
@@ -169,16 +169,20 @@ const os_date = function(L) {
 };
 
 const os_time = function(L) {
-    let t = new Date();
-    if (!lua_isnoneornil(L, 1))  /* called with arg */{
-        luaL_checktype(L, 1, LUA_TTABLE);  /* make sure table is at the top */
-        lua_settop(L, 1);
-        t.setSeconds(getfield(L, "sec", 0, 0));
-        t.setMinutes(getfield(L, "min", 0, 0));
-        t.setHours(getfield(L, "hour", 12, 0));
-        t.setDate(getfield(L, "day", -1, 0));
-        t.setMonth(getfield(L, "month", -1, 1));
-        t.setFullYear(getfield(L, "year", -1, 0));
+    let t;
+    if (lua_isnoneornil(L, 1))  /* called without args? */
+        t = new Date();  /* get current time */
+    else {
+        luaL_checktype(L, 1, LUA_TTABLE);
+        lua_settop(L, 1);  /* make sure table is at the top */
+        t = new Date(
+            getfield(L, "year", -1, 0),
+            getfield(L, "month", -1, 1),
+            getfield(L, "day", -1, 0),
+            getfield(L, "hour", 12, 0),
+            getfield(L, "min", 0, 0),
+            getfield(L, "sec", 0, 0)
+        )
         setallfields(L, t);
     }
 
diff --git a/test/loslib.test.js b/test/loslib.test.js
index a270d49..5f06a06 100644
--- a/test/loslib.test.js
+++ b/test/loslib.test.js
@@ -84,6 +84,27 @@ test('os.date', () => {
 });
 
 
+test('os.date normalisation', () => {
+    let L = lauxlib.luaL_newstate();
+    if (!L) throw Error("failed to create lua state");
+
+    let luaCode = `
+        return os.date('%Y-%m-%d', os.time({
+            day = 0,
+            month = 0,
+            year = 2014
+        }))
+    `;
+    {
+        lualib.luaL_openlibs(L);
+        expect(lauxlib.luaL_loadstring(L, to_luastring(luaCode))).toBe(lua.LUA_OK);
+        lua.lua_call(L, 0, -1);
+    }
+
+    expect(lua.lua_tojsstring(L, -1)).toBe("2013-11-30");
+});
+
+
 test('os.getenv', () => {
     let L = lauxlib.luaL_newstate();
     if (!L) throw Error("failed to create lua state");