--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/mujs/jserror.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,128 @@
+#include "jsi.h"
+
+#define QQ(X) #X
+#define Q(X) QQ(X)
+
+static int jsB_stacktrace(js_State *J, int skip)
+{
+	char buf[256];
+	int n = J->tracetop - skip;
+	if (n <= 0)
+		return 0;
+	for (; n > 0; --n) {
+		const char *name = J->trace[n].name;
+		const char *file = J->trace[n].file;
+		int line = J->trace[n].line;
+		if (line > 0) {
+			if (name[0])
+				snprintf(buf, sizeof buf, "\n\tat %s (%s:%d)", name, file, line);
+			else
+				snprintf(buf, sizeof buf, "\n\tat %s:%d", file, line);
+		} else
+			snprintf(buf, sizeof buf, "\n\tat %s (%s)", name, file);
+		js_pushstring(J, buf);
+		if (n < J->tracetop - skip)
+			js_concat(J);
+	}
+	return 1;
+}
+
+static void Ep_toString(js_State *J)
+{
+	const char *name = "Error";
+	const char *message = "";
+
+	if (!js_isobject(J, -1))
+		js_typeerror(J, "not an object");
+
+	if (js_hasproperty(J, 0, "name"))
+		name = js_tostring(J, -1);
+	if (js_hasproperty(J, 0, "message"))
+		message = js_tostring(J, -1);
+
+	if (name[0] == 0)
+		js_pushstring(J, message);
+	else if (message[0] == 0)
+		js_pushstring(J, name);
+	else {
+		js_pushstring(J, name);
+		js_pushstring(J, ": ");
+		js_concat(J);
+		js_pushstring(J, message);
+		js_concat(J);
+	}
+}
+
+static int jsB_ErrorX(js_State *J, js_Object *prototype)
+{
+	js_pushobject(J, jsV_newobject(J, JS_CERROR, prototype));
+	if (js_isdefined(J, 1)) {
+		js_pushstring(J, js_tostring(J, 1));
+		js_defproperty(J, -2, "message", JS_DONTENUM);
+	}
+	if (jsB_stacktrace(J, 1))
+		js_defproperty(J, -2, "stackTrace", JS_DONTENUM);
+	return 1;
+}
+
+static void js_newerrorx(js_State *J, const char *message, js_Object *prototype)
+{
+	js_pushobject(J, jsV_newobject(J, JS_CERROR, prototype));
+	js_pushstring(J, message);
+	js_setproperty(J, -2, "message");
+	if (jsB_stacktrace(J, 0))
+		js_setproperty(J, -2, "stackTrace");
+}
+
+#define DERROR(name, Name) \
+	static void jsB_##Name(js_State *J) { \
+		jsB_ErrorX(J, J->Name##_prototype); \
+	} \
+	void js_new##name(js_State *J, const char *s) { \
+		js_newerrorx(J, s, J->Name##_prototype); \
+	} \
+	void js_##name(js_State *J, const char *fmt, ...) { \
+		va_list ap; \
+		char buf[256]; \
+		va_start(ap, fmt); \
+		vsnprintf(buf, sizeof buf, fmt, ap); \
+		va_end(ap); \
+		js_newerrorx(J, buf, J->Name##_prototype); \
+		js_throw(J); \
+	}
+
+DERROR(error, Error)
+DERROR(evalerror, EvalError)
+DERROR(rangeerror, RangeError)
+DERROR(referenceerror, ReferenceError)
+DERROR(syntaxerror, SyntaxError)
+DERROR(typeerror, TypeError)
+DERROR(urierror, URIError)
+
+#undef DERROR
+
+void jsB_initerror(js_State *J)
+{
+	js_pushobject(J, J->Error_prototype);
+	{
+			jsB_props(J, "name", "Error");
+			jsB_propf(J, "Error.prototype.toString", Ep_toString, 0);
+	}
+	js_newcconstructor(J, jsB_Error, jsB_Error, "Error", 1);
+	js_defglobal(J, "Error", JS_DONTENUM);
+
+	#define IERROR(NAME) \
+		js_pushobject(J, J->NAME##_prototype); \
+		jsB_props(J, "name", Q(NAME)); \
+		js_newcconstructor(J, jsB_##NAME, jsB_##NAME, Q(NAME), 1); \
+		js_defglobal(J, Q(NAME), JS_DONTENUM);
+
+	IERROR(EvalError);
+	IERROR(RangeError);
+	IERROR(ReferenceError);
+	IERROR(SyntaxError);
+	IERROR(TypeError);
+	IERROR(URIError);
+
+	#undef IERROR
+}