Add a variant of dukky_instanceof which can take an index

2 files changed, 32 insertions, 0 deletions

diff --git a/javascript/dukky.c b/javascript/dukky.c
index 6c8c531fe..3e70b02fd 100644
--- a/javascript/dukky.c
+++ b/javascript/dukky.c
@@ -37,6 +37,37 @@
 
 #include <dom/dom.h>
 
+
+duk_bool_t
+dukky_instanceof_at(duk_context *ctx, duk_idx_t _idx, const char *klass)
+{
+	duk_idx_t idx = duk_normalize_index(ctx, _idx);
+	/* ... ??? */
+	if (!duk_check_type(ctx, idx, DUK_TYPE_OBJECT)) {
+		return false;
+	}
+	/* ... obj */
+	duk_get_global_string(ctx, "\xFF\xFFNETSURF_DUKTAPE_PROTOTYPES");
+	/* ... obj protos */
+	duk_get_prop_string(ctx, idx, klass);
+	/* ... obj protos goalproto */
+	duk_get_prototype(ctx, idx);
+	/* ... obj protos goalproto proto? */
+	while (!duk_is_undefined(ctx, -1)) {
+		if (duk_strict_equals(ctx, -1, -2)) {
+			duk_pop_3(ctx);
+			return true;
+		}
+		duk_get_prototype(ctx, -1);
+		/* ... obj protos goalproto proto proto? */
+		duk_replace(ctx, -2);
+		/* ... obj protos goalproto proto? */
+	}
+	duk_pop_3(ctx);
+	/* ... obj */
+	return false;
+}
+
 static duk_ret_t dukky_populate_object(duk_context *ctx)
 {
 	/* ... obj args protoname nargs */
diff --git a/javascript/dukky.h b/javascript/dukky.h
index abe21ba35..f484e3a13 100644
--- a/javascript/dukky.h
+++ b/javascript/dukky.h
@@ -28,5 +28,6 @@ duk_ret_t dukky_create_object(duk_context *ctx, const char *name, int args);
 duk_bool_t dukky_push_node_stacked(duk_context *ctx);
 duk_bool_t dukky_push_node(duk_context *ctx, struct dom_node *node);
 void dukky_inject_not_ctr(duk_context *ctx, int idx, const char *name);
+duk_bool_t dukky_instanceof_at(duk_context *ctx, duk_idx_t _idx, const char *klass);
 
 #endif