--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/mujs/jsfunction.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,231 @@
+#include "jsi.h"
+
+static void jsB_Function(js_State *J)
+{
+	int i, top = js_gettop(J);
+	js_Buffer *sb = NULL;
+	const char *body;
+	js_Ast *parse;
+	js_Function *fun;
+
+	if (js_try(J)) {
+		js_free(J, sb);
+		jsP_freeparse(J);
+		js_throw(J);
+	}
+
+	/* p1, p2, ..., pn */
+	if (top > 2) {
+		for (i = 1; i < top - 1; ++i) {
+			if (i > 1)
+				js_putc(J, &sb, ',');
+			js_puts(J, &sb, js_tostring(J, i));
+		}
+		js_putc(J, &sb, ')');
+		js_putc(J, &sb, 0);
+	}
+
+	/* body */
+	body = js_isdefined(J, top - 1) ? js_tostring(J, top - 1) : "";
+
+	parse = jsP_parsefunction(J, "[string]", sb ? sb->s : NULL, body);
+	fun = jsC_compilefunction(J, parse);
+
+	js_endtry(J);
+	js_free(J, sb);
+	jsP_freeparse(J);
+
+	js_newfunction(J, fun, J->GE);
+}
+
+static void jsB_Function_prototype(js_State *J)
+{
+	js_pushundefined(J);
+}
+
+static void Fp_toString(js_State *J)
+{
+	js_Object *self = js_toobject(J, 0);
+	js_Buffer *sb = NULL;
+	int i;
+
+	if (!js_iscallable(J, 0))
+		js_typeerror(J, "not a function");
+
+	if (self->type == JS_CFUNCTION || self->type == JS_CSCRIPT) {
+		js_Function *F = self->u.f.function;
+
+		if (js_try(J)) {
+			js_free(J, sb);
+			js_throw(J);
+		}
+
+		js_puts(J, &sb, "function ");
+		js_puts(J, &sb, F->name);
+		js_putc(J, &sb, '(');
+		for (i = 0; i < F->numparams; ++i) {
+			if (i > 0) js_putc(J, &sb, ',');
+			js_puts(J, &sb, F->vartab[i]);
+		}
+		js_puts(J, &sb, ") { [byte code] }");
+		js_putc(J, &sb, 0);
+
+		js_pushstring(J, sb->s);
+		js_endtry(J);
+		js_free(J, sb);
+	} else if (self->type == JS_CCFUNCTION) {
+		if (js_try(J)) {
+			js_free(J, sb);
+			js_throw(J);
+		}
+
+		js_puts(J, &sb, "function ");
+		js_puts(J, &sb, self->u.c.name);
+		js_puts(J, &sb, "() { [native code] }");
+		js_putc(J, &sb, 0);
+
+		js_pushstring(J, sb->s);
+		js_endtry(J);
+		js_free(J, sb);
+	} else {
+		js_pushliteral(J, "function () { }");
+	}
+}
+
+static void Fp_apply(js_State *J)
+{
+	int i, n;
+
+	if (!js_iscallable(J, 0))
+		js_typeerror(J, "not a function");
+
+	js_copy(J, 0);
+	js_copy(J, 1);
+
+	if (js_isnull(J, 2) || js_isundefined(J, 2)) {
+		n = 0;
+	} else {
+		n = js_getlength(J, 2);
+		if (n < 0)
+			n = 0;
+		for (i = 0; i < n; ++i)
+			js_getindex(J, 2, i);
+	}
+
+	js_call(J, n);
+}
+
+static void Fp_call(js_State *J)
+{
+	int i, top = js_gettop(J);
+
+	if (!js_iscallable(J, 0))
+		js_typeerror(J, "not a function");
+
+	for (i = 0; i < top; ++i)
+		js_copy(J, i);
+
+	js_call(J, top - 2);
+}
+
+static void callbound(js_State *J)
+{
+	int top = js_gettop(J);
+	int i, fun, args, n;
+
+	fun = js_gettop(J);
+	js_currentfunction(J);
+	js_getproperty(J, fun, "__TargetFunction__");
+	js_getproperty(J, fun, "__BoundThis__");
+
+	args = js_gettop(J);
+	js_getproperty(J, fun, "__BoundArguments__");
+	n = js_getlength(J, args);
+	if (n < 0)
+		n = 0;
+	for (i = 0; i < n; ++i)
+		js_getindex(J, args, i);
+	js_remove(J, args);
+
+	for (i = 1; i < top; ++i)
+		js_copy(J, i);
+
+	js_call(J, n + top - 1);
+}
+
+static void constructbound(js_State *J)
+{
+	int top = js_gettop(J);
+	int i, fun, args, n;
+
+	fun = js_gettop(J);
+	js_currentfunction(J);
+	js_getproperty(J, fun, "__TargetFunction__");
+
+	args = js_gettop(J);
+	js_getproperty(J, fun, "__BoundArguments__");
+	n = js_getlength(J, args);
+	if (n < 0)
+		n = 0;
+	for (i = 0; i < n; ++i)
+		js_getindex(J, args, i);
+	js_remove(J, args);
+
+	for (i = 1; i < top; ++i)
+		js_copy(J, i);
+
+	js_construct(J, n + top - 1);
+}
+
+static void Fp_bind(js_State *J)
+{
+	int i, top = js_gettop(J);
+	int n;
+
+	if (!js_iscallable(J, 0))
+		js_typeerror(J, "not a function");
+
+	n = js_getlength(J, 0);
+	if (n > top - 2)
+		n -= top - 2;
+	else
+		n = 0;
+
+	/* Reuse target function's prototype for HasInstance check. */
+	js_getproperty(J, 0, "prototype");
+	js_newcconstructor(J, callbound, constructbound, "[bind]", n);
+
+	/* target function */
+	js_copy(J, 0);
+	js_defproperty(J, -2, "__TargetFunction__", JS_READONLY | JS_DONTENUM | JS_DONTCONF);
+
+	/* bound this */
+	js_copy(J, 1);
+	js_defproperty(J, -2, "__BoundThis__", JS_READONLY | JS_DONTENUM | JS_DONTCONF);
+
+	/* bound arguments */
+	js_newarray(J);
+	for (i = 2; i < top; ++i) {
+		js_copy(J, i);
+		js_setindex(J, -2, i - 2);
+	}
+	js_defproperty(J, -2, "__BoundArguments__", JS_READONLY | JS_DONTENUM | JS_DONTCONF);
+}
+
+void jsB_initfunction(js_State *J)
+{
+	J->Function_prototype->u.c.name = "Function.prototype";
+	J->Function_prototype->u.c.function = jsB_Function_prototype;
+	J->Function_prototype->u.c.constructor = NULL;
+	J->Function_prototype->u.c.length = 0;
+
+	js_pushobject(J, J->Function_prototype);
+	{
+		jsB_propf(J, "Function.prototype.toString", Fp_toString, 2);
+		jsB_propf(J, "Function.prototype.apply", Fp_apply, 2);
+		jsB_propf(J, "Function.prototype.call", Fp_call, 1);
+		jsB_propf(J, "Function.prototype.bind", Fp_bind, 1);
+	}
+	js_newcconstructor(J, jsB_Function, jsB_Function, "Function", 1);
+	js_defglobal(J, "Function", JS_DONTENUM);
+}