vbscript: Added interp_add implementation.

dlls/vbscript/interp.c

@@ -393,8 +393,26 @@ static HRESULT interp_concat(exec_ctx_t *ctx)
 
 static HRESULT interp_add(exec_ctx_t *ctx)
 {
-    FIXME("\n");
-    return E_NOTIMPL;
+    variant_val_t r, l;
+    VARIANT v;
+    HRESULT hres;
+
+    TRACE("\n");
+
+    hres = stack_pop_val(ctx, &r);
+    if(FAILED(hres))
+        return hres;
+
+    hres = stack_pop_val(ctx, &l);
+    if(SUCCEEDED(hres)) {
+        hres = VarAdd(l.v, r.v, &v);
+        release_val(&l);
+    }
+    release_val(&r);
+    if(FAILED(hres))
+        return hres;
+
+    return stack_push(ctx, &v);
 }
 
 static HRESULT interp_sub(exec_ctx_t *ctx)

dlls/vbscript/tests/lang.vbs

@@ -70,4 +70,9 @@ Call ok(1 & 100000 = "1100000", "1 & 100000 = " & (1 & 100000))
 '    Call ok(true & false = "TrueFalse", "true & false = " & (true & false))
 'end if
 
+Call ok(2+2 = 4, "2+2 = " & (2+2))
+Call ok(false + 6 + true = 5, "false + 6 + true <> 5")
+Call ok(getVT(2+null) = "VT_NULL", "getVT(2+null) = " & getVT(2+null))
+Call ok(2+empty = 2, "2+empty = " & (2+empty))
+
 reportSuccess()