--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/source/pdf/pdf-js.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,1331 @@
+// Copyright (C) 2004-2022 Artifex Software, Inc.
+//
+// This file is part of MuPDF.
+//
+// MuPDF is free software: you can redistribute it and/or modify it under the
+// terms of the GNU Affero General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// MuPDF is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+// details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
+//
+// Alternative licensing terms are available from the licensor.
+// For commercial licensing, see <https://www.artifex.com/> or contact
+// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
+// CA 94129, USA, for further information.
+
+#include "mupdf/fitz.h"
+#include "mupdf/pdf.h"
+
+#if FZ_ENABLE_JS
+
+#include "mujs.h"
+
+#include <stdarg.h>
+#include <string.h>
+
+struct pdf_js
+{
+	fz_context *ctx;
+	pdf_document *doc;
+	pdf_obj *form;
+	js_State *imp;
+	pdf_js_console *console;
+	void *console_user;
+};
+
+FZ_NORETURN static void rethrow(pdf_js *js)
+{
+	js_newerror(js->imp, fz_convert_error(js->ctx, NULL));
+	js_throw(js->imp);
+}
+
+/* Unpack argument object with named arguments into actual parameters. */
+static pdf_js *unpack_arguments(js_State *J, ...)
+{
+	if (js_isobject(J, 1))
+	{
+		int i = 1;
+		va_list args;
+
+		js_copy(J, 1);
+
+		va_start(args, J);
+		for (;;)
+		{
+			const char *s = va_arg(args, const char *);
+			if (!s)
+				break;
+			js_getproperty(J, -1, s);
+			js_replace(J, i++);
+		}
+		va_end(args);
+
+		js_pop(J, 1);
+	}
+	return js_getcontext(J);
+}
+
+static void app_alert(js_State *J)
+{
+	pdf_js *js = unpack_arguments(J, "cMsg", "nIcon", "nType", "cTitle", "oDoc", "oCheckbox", NULL);
+	pdf_alert_event evt;
+
+	/* TODO: Currently we do not support app.openDoc() in javascript actions, hence
+	oDoc can only point to the current document (or not be passed). When mupdf
+	supports opening other documents oDoc must be converted to a pdf_document * that
+	can be passed to the callback. In the mean time, we just pas the current document.
+	*/
+	evt.doc = js->doc;
+
+	evt.message = js_tostring(J, 1);
+	evt.icon_type = js_tointeger(J, 2);
+	evt.button_group_type = js_tointeger(J, 3);
+	evt.title = js_isdefined(J, 4) ? js_tostring(J, 4) : "PDF alert";
+
+	evt.has_check_box = 0;
+	evt.check_box_message = NULL;
+	evt.initially_checked = 0;
+	evt.finally_checked = 0;
+
+	if (js_isobject(J, 6))
+	{
+		evt.has_check_box = 1;
+		evt.check_box_message = "Do not show this message again";
+		if (js_hasproperty(J, 6, "cMsg"))
+		{
+			if (js_iscoercible(J, -1))
+				evt.check_box_message = js_tostring(J, -1);
+			js_pop(J, 1);
+		}
+		if (js_hasproperty(J, 6, "bInitialValue"))
+		{
+			evt.initially_checked = js_tointeger(J, -1);
+			js_pop(J, 1);
+		}
+		if (js_hasproperty(J, 6, "bAfterValue"))
+		{
+			evt.finally_checked = js_tointeger(J, -1);
+			js_pop(J, 1);
+		}
+	}
+
+	/* These are the default buttons automagically "pressed"
+	when the dialog box window is closed in Acrobat. */
+	switch (evt.button_group_type)
+	{
+	default:
+	case PDF_ALERT_BUTTON_GROUP_OK:
+		evt.button_pressed = PDF_ALERT_BUTTON_OK;
+		break;
+	case PDF_ALERT_BUTTON_GROUP_OK_CANCEL:
+		evt.button_pressed = PDF_ALERT_BUTTON_CANCEL;
+		break;
+	case PDF_ALERT_BUTTON_GROUP_YES_NO:
+		evt.button_pressed = PDF_ALERT_BUTTON_YES;
+		break;
+	case PDF_ALERT_BUTTON_GROUP_YES_NO_CANCEL:
+		evt.button_pressed = PDF_ALERT_BUTTON_CANCEL;
+		break;
+	}
+
+	fz_try(js->ctx)
+		pdf_event_issue_alert(js->ctx, js->doc, &evt);
+	fz_catch(js->ctx)
+		rethrow(js);
+
+	if (js_isobject(J, 6))
+	{
+		js_pushboolean(js->imp, evt.finally_checked);
+		js_setproperty(js->imp, 6, "bAfterValue");
+	}
+
+	js_pushnumber(J, evt.button_pressed);
+}
+
+static void app_execMenuItem(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	const char *cMenuItem = js_tostring(J, 1);
+	fz_try(js->ctx)
+		pdf_event_issue_exec_menu_item(js->ctx, js->doc, cMenuItem);
+	fz_catch(js->ctx)
+		rethrow(js);
+}
+
+static void app_launchURL(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	const char *cUrl = js_tostring(J, 1);
+	int bNewFrame = js_toboolean(J, 1);
+	fz_try(js->ctx)
+		pdf_event_issue_launch_url(js->ctx, js->doc, cUrl, bNewFrame);
+	fz_catch(js->ctx)
+		rethrow(js);
+}
+
+static void field_finalize(js_State *J, void *p)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_drop_obj(js->ctx, p);
+}
+
+static void field_buttonSetCaption(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_obj *field = js_touserdata(J, 0, "Field");
+	const char *cCaption = js_tostring(J, 1);
+	fz_try(js->ctx)
+		pdf_field_set_button_caption(js->ctx, field, cCaption);
+	fz_catch(js->ctx)
+		rethrow(js);
+}
+
+static void field_getName(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_obj *field = js_touserdata(J, 0, "Field");
+	char *name = NULL;
+	fz_try(js->ctx)
+		name = pdf_load_field_name(js->ctx, field);
+	fz_catch(js->ctx)
+		rethrow(js);
+	if (js_try(J)) {
+		fz_free(js->ctx, name);
+		js_throw(J);
+	} else {
+		js_pushstring(J, name);
+		js_endtry(J);
+		fz_free(js->ctx, name);
+	}
+}
+
+static void field_setName(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	fz_warn(js->ctx, "Unexpected call to field_setName");
+}
+
+static void field_getDisplay(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_obj *field = js_touserdata(J, 0, "Field");
+	int display = 0;
+	fz_try(js->ctx)
+		display = pdf_field_display(js->ctx, field);
+	fz_catch(js->ctx)
+		rethrow(js);
+	js_pushnumber(J, display);
+}
+
+static void field_setDisplay(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_obj *field = js_touserdata(J, 0, "Field");
+	int display = js_tonumber(J, 1);
+	fz_try(js->ctx)
+		pdf_field_set_display(js->ctx, field, display);
+	fz_catch(js->ctx)
+		rethrow(js);
+}
+
+static pdf_obj *load_color(pdf_js *js, int idx)
+{
+	fz_context *ctx = js->ctx;
+	pdf_document *doc = js->doc;
+	js_State *J = js->imp;
+
+	pdf_obj *color = NULL;
+	int i, n;
+	float c;
+
+	n = js_getlength(J, idx);
+
+	/* The only legitimate color expressed as an array of length 1
+	 * is [T], meaning transparent. Return a NULL object to represent
+	 * transparent */
+	if (n <= 1)
+		return NULL;
+
+	fz_var(color);
+
+	fz_try(ctx)
+	{
+		color = pdf_new_array(ctx, doc, n-1);
+		for (i = 0; i < n-1; i++)
+		{
+			js_getindex(J, idx, i+1);
+			c = js_tonumber(J, -1);
+			js_pop(J, 1);
+
+			pdf_array_push_real(ctx, color, c);
+		}
+	}
+	fz_catch(ctx)
+	{
+		pdf_drop_obj(ctx, color);
+		rethrow(js);
+	}
+
+	return color;
+}
+
+static void field_getFillColor(js_State *J)
+{
+	js_pushundefined(J);
+}
+
+static void field_setFillColor(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_obj *field = js_touserdata(J, 0, "Field");
+	pdf_obj *color = load_color(js, 1);
+	fz_try(js->ctx)
+		pdf_field_set_fill_color(js->ctx, field, color);
+	fz_always(js->ctx)
+		pdf_drop_obj(js->ctx, color);
+	fz_catch(js->ctx)
+		rethrow(js);
+}
+
+static void field_getTextColor(js_State *J)
+{
+	js_pushundefined(J);
+}
+
+static void field_setTextColor(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_obj *field = js_touserdata(J, 0, "Field");
+	pdf_obj *color = load_color(js, 1);
+	fz_try(js->ctx)
+		pdf_field_set_text_color(js->ctx, field, color);
+	fz_always(js->ctx)
+		pdf_drop_obj(js->ctx, color);
+	fz_catch(js->ctx)
+		rethrow(js);
+}
+
+static void field_getBorderStyle(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_obj *field = js_touserdata(J, 0, "Field");
+	const char *border_style = NULL;
+	fz_try(js->ctx)
+		border_style = pdf_field_border_style(js->ctx, field);
+	fz_catch(js->ctx)
+		rethrow(js);
+	js_pushstring(J, border_style);
+}
+
+static void field_setBorderStyle(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_obj *field = js_touserdata(J, 0, "Field");
+	const char *border_style = js_tostring(J, 1);
+	fz_try(js->ctx)
+		pdf_field_set_border_style(js->ctx, field, border_style);
+	fz_catch(js->ctx)
+		rethrow(js);
+}
+
+static void field_getValue(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_obj *field = js_touserdata(J, 0, "Field");
+	const char *str = NULL;
+	char *end;
+	double num;
+
+	fz_try(js->ctx)
+		str = pdf_field_value(js->ctx, field);
+	fz_catch(js->ctx)
+		rethrow(js);
+
+	num = strtod(str, &end);
+	if (*str && *end == 0)
+		js_pushnumber(J, num);
+	else
+		js_pushstring(J, str);
+}
+
+static void field_setValue(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_obj *field = js_touserdata(J, 0, "Field");
+	const char *value = js_tostring(J, 1);
+
+	fz_try(js->ctx)
+		(void)pdf_set_field_value(js->ctx, js->doc, field, value, 0);
+	fz_catch(js->ctx)
+		rethrow(js);
+}
+
+static void field_getType(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_obj *field = js_touserdata(J, 0, "Field");
+	const char *type;
+
+	fz_try(js->ctx)
+		type = pdf_field_type_string(js->ctx, field);
+	fz_catch(js->ctx)
+		rethrow(js);
+
+	js_pushstring(J, type);
+}
+
+static void field_setType(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	fz_warn(js->ctx, "Unexpected call to field_setType");
+}
+
+static void doc_getField(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	fz_context *ctx = js->ctx;
+	const char *cName = js_tostring(J, 1);
+	pdf_obj *dict = NULL;
+
+	fz_try(ctx)
+		dict = pdf_lookup_field(ctx, js->form, cName);
+	fz_catch(ctx)
+		rethrow(js);
+
+	if (dict)
+	{
+		js_getregistry(J, "Field");
+		js_newuserdata(J, "Field", pdf_keep_obj(js->ctx, dict), field_finalize);
+	}
+	else
+	{
+		js_pushnull(J);
+	}
+}
+
+static void doc_getNumPages(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	int pages = pdf_count_pages(js->ctx, js->doc);
+	js_pushnumber(J, pages);
+}
+
+static void doc_setNumPages(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	fz_warn(js->ctx, "Unexpected call to doc_setNumPages");
+}
+
+static void doc_getMetaString(js_State *J, const char *key)
+{
+	pdf_js *js = js_getcontext(J);
+	char buf[256];
+	int ret;
+
+	fz_try(js->ctx)
+		ret = fz_lookup_metadata(js->ctx, &js->doc->super, key, buf, nelem(buf)) > 0;
+	fz_catch(js->ctx)
+		rethrow(js);
+
+	if (ret > 0)
+		js_pushstring(J, buf);
+	else
+		js_pushundefined(J);
+}
+
+static void doc_setMetaString(js_State *J, const char *key)
+{
+	pdf_js *js = js_getcontext(J);
+	const char *value = js_tostring(J, 1);
+	fz_set_metadata(js->ctx, &js->doc->super, key, value);
+}
+
+static void doc_getMetaDate(js_State *J, const char *key)
+{
+	pdf_js *js = js_getcontext(J);
+	char buf[256];
+	int ret;
+	double time;
+
+	fz_try(js->ctx)
+	{
+		ret = fz_lookup_metadata(js->ctx, &js->doc->super, key, buf, nelem(buf)) > 0;
+		if (ret > 0)
+			time = pdf_parse_date(js->ctx, buf);
+	}
+	fz_catch(js->ctx)
+		rethrow(js);
+
+	if (ret > 0)
+	{
+		js_getglobal(J, "Date");
+		js_pushnumber(J, time * 1000);
+		js_construct(J, 1);
+	}
+	else
+		js_pushundefined(J);
+}
+
+static void doc_setMetaDate(js_State *J, const char *key)
+{
+	pdf_js *js = js_getcontext(J);
+	int64_t time;
+	char value[40];
+
+	// Coerce the argument into a date object and extract the time value.
+	js_getglobal(J, "Date");
+	js_copy(J, 1);
+	js_construct(J, 1);
+	time = js_tonumber(J, -1) / 1000;
+	js_pop(J, 1);
+
+	fz_try(js->ctx)
+		if (pdf_format_date(js->ctx, time, value, nelem(value)))
+			fz_set_metadata(js->ctx, &js->doc->super, key, value);
+	fz_catch(js->ctx)
+		rethrow(js);
+}
+
+static void doc_getAuthor(js_State *J) { doc_getMetaString(J, FZ_META_INFO_AUTHOR); }
+static void doc_setAuthor(js_State *J) { doc_setMetaString(J, FZ_META_INFO_AUTHOR); }
+static void doc_getTitle(js_State *J) { doc_getMetaString(J, FZ_META_INFO_TITLE); }
+static void doc_setTitle(js_State *J) { doc_setMetaString(J, FZ_META_INFO_TITLE); }
+static void doc_getSubject(js_State *J) { doc_getMetaString(J, FZ_META_INFO_SUBJECT); }
+static void doc_setSubject(js_State *J) { doc_setMetaString(J, FZ_META_INFO_SUBJECT); }
+static void doc_getKeywords(js_State *J) { doc_getMetaString(J, FZ_META_INFO_KEYWORDS); }
+static void doc_setKeywords(js_State *J) { doc_setMetaString(J, FZ_META_INFO_KEYWORDS); }
+static void doc_getCreator(js_State *J) { doc_getMetaString(J, FZ_META_INFO_CREATOR); }
+static void doc_setCreator(js_State *J) { doc_setMetaString(J, FZ_META_INFO_CREATOR); }
+static void doc_getProducer(js_State *J) { doc_getMetaString(J, FZ_META_INFO_PRODUCER); }
+static void doc_setProducer(js_State *J) { doc_setMetaString(J, FZ_META_INFO_PRODUCER); }
+static void doc_getCreationDate(js_State *J) { doc_getMetaDate(J, FZ_META_INFO_CREATIONDATE); }
+static void doc_setCreationDate(js_State *J) { doc_setMetaDate(J, FZ_META_INFO_CREATIONDATE); }
+static void doc_getModDate(js_State *J) { doc_getMetaDate(J, FZ_META_INFO_MODIFICATIONDATE); }
+static void doc_setModDate(js_State *J) { doc_setMetaDate(J, FZ_META_INFO_MODIFICATIONDATE); }
+
+static void doc_resetForm(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	pdf_obj *field;
+	fz_context *ctx = js->ctx;
+	int i, n;
+
+	/* An array of fields has been passed in. Call pdf_reset_field on each item. */
+	if (js_isarray(J, 1))
+	{
+		n = js_getlength(J, 1);
+		for (i = 0; i < n; ++i)
+		{
+			js_getindex(J, 1, i);
+			field = pdf_lookup_field(ctx, js->form, js_tostring(J, -1));
+			if (field)
+				pdf_field_reset(ctx, js->doc, field);
+			js_pop(J, 1);
+		}
+	}
+
+	/* No argument or null passed in means reset all. */
+	else
+	{
+		n = pdf_array_len(ctx, js->form);
+		for (i = 0; i < n; i++)
+		{
+			fz_try(ctx)
+				pdf_field_reset(ctx, js->doc, pdf_array_get(ctx, js->form, i));
+			fz_catch(ctx)
+				rethrow(js);
+		}
+	}
+}
+
+static void doc_print(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	fz_try(js->ctx)
+		pdf_event_issue_print(js->ctx, js->doc);
+	fz_catch(js->ctx)
+		rethrow(js);
+}
+
+static void doc_mailDoc(js_State *J)
+{
+	pdf_js *js = unpack_arguments(J, "bUI", "cTo", "cCc", "cBcc", "cSubject", "cMessage", NULL);
+	pdf_mail_doc_event evt;
+
+	evt.ask_user = js_isdefined(J, 1) ? js_toboolean(J, 1) : 1;
+	evt.to = js_tostring(J, 2);
+	evt.cc = js_tostring(J, 3);
+	evt.bcc = js_tostring(J, 4);
+	evt.subject = js_tostring(J, 5);
+	evt.message = js_tostring(J, 6);
+
+	fz_try(js->ctx)
+		pdf_event_issue_mail_doc(js->ctx, js->doc, &evt);
+	fz_catch(js->ctx)
+		rethrow(js);
+}
+
+static void doc_calculateNow(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	fz_try(js->ctx)
+		pdf_calculate_form(js->ctx, js->doc);
+	fz_catch(js->ctx)
+		rethrow(js);
+}
+
+static void console_println(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	if (js->console && js->console->write)
+	{
+		int i, top = js_gettop(J);
+		js->console->write(js->console_user, "\n");
+		for (i = 1; i < top; ++i) {
+			const char *s = js_tostring(J, i);
+			if (i > 1)
+				js->console->write(js->console_user, " ");
+			js->console->write(js->console_user, s);
+		}
+	}
+	js_pushboolean(J, 1);
+}
+
+static void console_clear(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	if (js->console && js->console->clear)
+		js->console->clear(js->console_user);
+	js_pushundefined(J);
+}
+
+static void console_show(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	if (js->console && js->console->show)
+		js->console->show(js->console_user);
+	js_pushundefined(J);
+}
+
+static void console_hide(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	if (js->console && js->console->hide)
+		js->console->hide(js->console_user);
+	js_pushundefined(J);
+}
+
+static void util_printf_d(fz_context *ctx, fz_buffer *out, int ds, int sign, int pad, unsigned int w, int base, int value)
+{
+	static const char *digits = "0123456789abcdef";
+	char buf[50];
+	unsigned int a, i;
+	int m = 0;
+
+	if (w > sizeof buf)
+		w = sizeof buf;
+
+	if (value < 0)
+	{
+		sign = '-';
+		a = -value;
+	}
+	else
+	{
+		a = value;
+	}
+
+	i = 0;
+	do
+	{
+		buf[i++] = digits[a % base];
+		a /= base;
+		if (a > 0 && ++m == 3)
+		{
+			if (ds == 0) buf[i++] = ',';
+			if (ds == 2) buf[i++] = '.';
+			m = 0;
+		}
+	} while (a);
+
+	if (sign)
+	{
+		if (pad == '0')
+			while (i < w - 1)
+				buf[i++] = pad;
+		buf[i++] = sign;
+	}
+	while (i < w)
+		buf[i++] = pad;
+
+	while (i > 0)
+		fz_append_byte(ctx, out, buf[--i]);
+}
+
+static void util_printf_f(fz_context *ctx, fz_buffer *out, int ds, int sign, int pad, int special, unsigned int w, int p, double value)
+{
+	char buf[40], *point, *digits = buf;
+	size_t n = 0;
+	int m = 0;
+
+	fz_snprintf(buf, sizeof buf, "%.*f", p, value);
+
+	if (*digits == '-')
+	{
+		sign = '-';
+		++digits;
+	}
+
+	if (*digits != '.' && (*digits < '0' || *digits > '9'))
+	{
+		fz_append_string(ctx, out, "nan");
+		return;
+	}
+
+	n = strlen(digits);
+	if (sign)
+		++n;
+	point = strchr(digits, '.');
+	if (point)
+		m = 3 - (point - digits) % 3;
+	else
+	{
+		m = 3 - n % 3;
+		if (special)
+			++n;
+	}
+	if (m == 3)
+		m = 0;
+
+	if (pad == '0' && sign)
+		fz_append_byte(ctx, out, sign);
+	for (; n < w; ++n)
+		fz_append_byte(ctx, out, pad);
+	if (pad == ' ' && sign)
+		fz_append_byte(ctx, out, sign);
+
+	while (*digits && *digits != '.')
+	{
+		fz_append_byte(ctx, out, *digits++);
+		if (++m == 3 && *digits && *digits != '.')
+		{
+			if (ds == 0) fz_append_byte(ctx, out, ',');
+			if (ds == 2) fz_append_byte(ctx, out, '.');
+			m = 0;
+		}
+	}
+
+	if (*digits == '.' || special)
+	{
+		if (ds == 0 || ds == 1)
+			fz_append_byte(ctx, out, '.');
+		else
+			fz_append_byte(ctx, out, ',');
+	}
+
+	if (*digits == '.')
+	{
+		++digits;
+		while (*digits)
+			fz_append_byte(ctx, out, *digits++);
+	}
+}
+
+static void util_printf(js_State *J)
+{
+	pdf_js *js = js_getcontext(J);
+	fz_context *ctx = js->ctx;
+	const char *fmt = js_tostring(J, 1);
+	fz_buffer *out = NULL;
+	int ds, p, sign, pad, special;
+	unsigned int w;
+	int c, i = 1;
+	int failed = 0;
+	const char *str;
+
+	fz_var(out);
+	fz_try(ctx)
+	{
+		out = fz_new_buffer(ctx, 256);
+
+		while ((c = *fmt++) != 0)
+		{
+			if (c == '%')
+			{
+				c = *fmt++;
+
+				ds = 1;
+				if (c == ',')
+				{
+					c = *fmt++;
+					if (!c)
+						break;
+					ds = c - '0';
+				}
+
+				special = 0;
+				sign = 0;
+				pad = ' ';
+				while (c == ' ' || c == '+' || c == '0' || c == '#')
+				{
+					if (c == '+') sign = '+';
+					else if (c == ' ') sign = ' ';
+					else if (c == '0') pad = '0';
+					else if (c == '#') special = 1;
+					c = *fmt++;
+				}
+				if (!pad)
+					pad = ' ';
+				if (!c)
+					break;
+
+				w = 0;
+				while (c >= '0' && c <= '9')
+				{
+					w = w * 10 + (c - '0');
+					c = *fmt++;
+				}
+				if (!c)
+					break;
+
+				p = 0;
+				if (c == '.')
+				{
+					c = *fmt++;
+					while (c >= '0' && c <= '9')
+					{
+						p = p * 10 + (c - '0');
+						c = *fmt++;
+					}
+				}
+				else
+				{
+					special = 1;
+				}
+				if (!c)
+					break;
+
+				switch (c)
+				{
+				case '%':
+					fz_append_byte(ctx, out, '%');
+					break;
+				case 'x':
+					util_printf_d(ctx, out, ds, sign, pad, w, 16, js_tryinteger(J, ++i, 0));
+					break;
+				case 'd':
+					util_printf_d(ctx, out, ds, sign, pad, w, 10, js_tryinteger(J, ++i, 0));
+					break;
+				case 'f':
+					util_printf_f(ctx, out, ds, sign, pad, special, w, p, js_trynumber(J, ++i, 0));
+					break;
+				case 's':
+				default:
+					fz_append_string(ctx, out, js_trystring(J, ++i, ""));
+				}
+			}
+			else
+			{
+				fz_append_byte(ctx, out, c);
+			}
+		}
+
+		str = fz_string_from_buffer(ctx, out);
+		if (js_try(J))
+		{
+			failed = 1;
+		}
+		else
+		{
+			js_pushstring(J, str);
+			js_endtry(J);
+		}
+	}
+	fz_always(ctx)
+		fz_drop_buffer(ctx, out);
+	fz_catch(ctx)
+		rethrow(js);
+
+	if (failed)
+		js_throw(J);
+}
+
+static void addmethod(js_State *J, const char *name, js_CFunction fun, int n)
+{
+	const char *realname = strchr(name, '.');
+	realname = realname ? realname + 1 : name;
+	js_newcfunction(J, fun, name, n);
+	js_defproperty(J, -2, realname, JS_READONLY | JS_DONTENUM | JS_DONTCONF);
+}
+
+static void addproperty(js_State *J, const char *name, js_CFunction getfun, js_CFunction setfun)
+{
+	const char *realname = strchr(name, '.');
+	realname = realname ? realname + 1 : name;
+	js_newcfunction(J, getfun, name, 0);
+	js_newcfunction(J, setfun, name, 1);
+	js_defaccessor(J, -3, realname, JS_READONLY | JS_DONTENUM | JS_DONTCONF);
+}
+
+static int declare_dom(pdf_js *js)
+{
+	js_State *J = js->imp;
+
+	if (js_try(J))
+	{
+		return -1;
+	}
+
+	/* Allow access to the global environment via the 'global' name */
+	js_pushglobal(J);
+	js_defglobal(J, "global", JS_READONLY | JS_DONTCONF | JS_DONTENUM);
+
+	/* Create the 'event' object */
+	js_newobject(J);
+	js_defglobal(J, "event", JS_READONLY | JS_DONTCONF | JS_DONTENUM);
+
+	/* Create the 'util' object */
+	js_newobject(J);
+	{
+		// TODO: util.printd
+		// TODO: util.printx
+		addmethod(J, "util.printf", util_printf, 1);
+	}
+	js_defglobal(J, "util", JS_READONLY | JS_DONTCONF | JS_DONTENUM);
+
+	/* Create the 'app' object */
+	js_newobject(J);
+	{
+#ifdef _WIN32
+		js_pushstring(J, "WIN");
+#elif defined(__APPLE__)
+		js_pushstring(J, "MAC");
+#else
+		js_pushstring(J, "UNIX");
+#endif
+		js_defproperty(J, -2, "app.platform", JS_READONLY | JS_DONTENUM | JS_DONTCONF);
+
+		addmethod(J, "app.alert", app_alert, 6);
+		addmethod(J, "app.execMenuItem", app_execMenuItem, 1);
+		addmethod(J, "app.launchURL", app_launchURL, 2);
+	}
+	js_defglobal(J, "app", JS_READONLY | JS_DONTCONF | JS_DONTENUM);
+
+	/* Create the Field prototype object */
+	js_newobject(J);
+	{
+		addproperty(J, "Field.value", field_getValue, field_setValue);
+		addproperty(J, "Field.type", field_getType, field_setType);
+		addproperty(J, "Field.borderStyle", field_getBorderStyle, field_setBorderStyle);
+		addproperty(J, "Field.textColor", field_getTextColor, field_setTextColor);
+		addproperty(J, "Field.fillColor", field_getFillColor, field_setFillColor);
+		addproperty(J, "Field.display", field_getDisplay, field_setDisplay);
+		addproperty(J, "Field.name", field_getName, field_setName);
+		addmethod(J, "Field.buttonSetCaption", field_buttonSetCaption, 1);
+	}
+	js_setregistry(J, "Field");
+
+	/* Create the console object */
+	js_newobject(J);
+	{
+		addmethod(J, "console.println", console_println, 1);
+		addmethod(J, "console.clear", console_clear, 0);
+		addmethod(J, "console.show", console_show, 0);
+		addmethod(J, "console.hide", console_hide, 0);
+	}
+	js_defglobal(J, "console", JS_READONLY | JS_DONTCONF | JS_DONTENUM);
+
+	/* Put all of the Doc methods in the global object, which is used as
+	 * the 'this' binding for regular non-strict function calls. */
+	js_pushglobal(J);
+	{
+		addproperty(J, "Doc.numPages", doc_getNumPages, doc_setNumPages);
+		addproperty(J, "Doc.author", doc_getAuthor, doc_setAuthor);
+		addproperty(J, "Doc.title", doc_getTitle, doc_setTitle);
+		addproperty(J, "Doc.subject", doc_getSubject, doc_setSubject);
+		addproperty(J, "Doc.keywords", doc_getKeywords, doc_setKeywords);
+		addproperty(J, "Doc.creator", doc_getCreator, doc_setCreator);
+		addproperty(J, "Doc.producer", doc_getProducer, doc_setProducer);
+		addproperty(J, "Doc.creationDate", doc_getCreationDate, doc_setCreationDate);
+		addproperty(J, "Doc.modDate", doc_getModDate, doc_setModDate);
+		addmethod(J, "Doc.getField", doc_getField, 1);
+		addmethod(J, "Doc.resetForm", doc_resetForm, 0);
+		addmethod(J, "Doc.calculateNow", doc_calculateNow, 0);
+		addmethod(J, "Doc.print", doc_print, 0);
+		addmethod(J, "Doc.mailDoc", doc_mailDoc, 6);
+	}
+	js_pop(J, 1);
+
+	js_endtry(J);
+
+	return 0;
+}
+
+static int preload_helpers(pdf_js *js)
+{
+	if (js_try(js->imp))
+		return -1;
+
+	/* When testing on the cluster:
+	 * Use a fixed date for "new Date" and Date.now().
+	 * Sadly, this breaks uses of the Date function without the new keyword.
+	 * Return a fixed random sequence from Math.random().
+	 */
+#ifdef CLUSTER
+	js_dostring(js->imp,
+"var MuPDFOldDate = Date\n"
+"Date = function() { return new MuPDFOldDate(298252800000); }\n"
+"Date.now = function() { return 298252800000; }\n"
+"Date.UTC = function() { return 298252800000; }\n"
+"Date.parse = MuPDFOldDate.parse;\n"
+"Math.random = function() { return (Math.random.seed = Math.random.seed * 48271 % 2147483647) / 2147483647; }\n"
+"Math.random.seed = 217;\n"
+	);
+#endif
+
+	js_dostring(js->imp,
+#include "js/util.js.h"
+	);
+
+	js_endtry(js->imp);
+	return 0;
+}
+
+void pdf_drop_js(fz_context *ctx, pdf_js *js)
+{
+	if (js)
+	{
+		if (js->console && js->console->drop)
+			js->console->drop(js->console, js->console_user);
+		js_freestate(js->imp);
+		fz_free(ctx, js);
+	}
+}
+
+static void *pdf_js_alloc(void *actx, void *ptr, int n)
+{
+	return fz_realloc_no_throw(actx, ptr, n);
+}
+
+static void default_js_console_clear(void *user)
+{
+	fz_context *ctx = user;
+	fz_write_string(ctx, fz_stddbg(ctx), "--- clear console ---\n");
+}
+
+static void default_js_console_write(void *user, const char *message)
+{
+	fz_context *ctx = user;
+	fz_write_string(ctx, fz_stddbg(ctx), message);
+}
+
+static pdf_js_console default_js_console = {
+	NULL,
+	NULL,
+	NULL,
+	default_js_console_clear,
+	default_js_console_write,
+};
+
+static pdf_js *pdf_new_js(fz_context *ctx, pdf_document *doc)
+{
+	pdf_js *js = fz_malloc_struct(ctx, pdf_js);
+
+	js->ctx = ctx;
+	js->doc = doc;
+
+	fz_try(ctx)
+	{
+		pdf_obj *root, *acroform;
+
+		/* Find the form array */
+		root = pdf_dict_get(ctx, pdf_trailer(ctx, doc), PDF_NAME(Root));
+		acroform = pdf_dict_get(ctx, root, PDF_NAME(AcroForm));
+		js->form = pdf_dict_get(ctx, acroform, PDF_NAME(Fields));
+
+		/* Initialise the javascript engine, passing the fz_context for use in memory allocation. */
+		js->imp = js_newstate(pdf_js_alloc, ctx, 0);
+		if (!js->imp)
+			fz_throw(ctx, FZ_ERROR_LIBRARY, "cannot initialize javascript engine");
+
+		/* Also set our pdf_js context, so we can retrieve it in callbacks. */
+		js_setcontext(js->imp, js);
+
+		js->console = &default_js_console;
+		js->console_user = js->ctx;
+
+		if (declare_dom(js))
+			fz_throw(ctx, FZ_ERROR_LIBRARY, "cannot initialize dom interface");
+		if (preload_helpers(js))
+			fz_throw(ctx, FZ_ERROR_LIBRARY, "cannot initialize helper functions");
+	}
+	fz_catch(ctx)
+	{
+		pdf_drop_js(ctx, js);
+		fz_rethrow(ctx);
+	}
+
+	return js;
+}
+
+static void pdf_js_load_document_level(pdf_js *js)
+{
+	fz_context *ctx = js->ctx;
+	pdf_document *doc = js->doc;
+	pdf_obj *javascript;
+	int len, i;
+	int in_op = 0;
+
+	javascript = pdf_load_name_tree(ctx, doc, PDF_NAME(JavaScript));
+	len = pdf_dict_len(ctx, javascript);
+
+	fz_var(in_op);
+
+	fz_try(ctx)
+	{
+		pdf_begin_operation(ctx, doc, "Document level Javascript");
+		in_op = 1;
+		for (i = 0; i < len; i++)
+		{
+			pdf_obj *fragment = pdf_dict_get_val(ctx, javascript, i);
+			pdf_obj *code = pdf_dict_get(ctx, fragment, PDF_NAME(JS));
+			char *codebuf = pdf_load_stream_or_string_as_utf8(ctx, code);
+			char buf[100];
+			if (pdf_is_indirect(ctx, code))
+				fz_snprintf(buf, sizeof buf, "%d", pdf_to_num(ctx, code));
+			else
+				fz_snprintf(buf, sizeof buf, "Root/Names/JavaScript/Names/%d/JS", (i+1)*2);
+			pdf_js_execute(js, buf, codebuf, NULL);
+			fz_free(ctx, codebuf);
+		}
+		pdf_end_operation(ctx, doc);
+	}
+	fz_always(ctx)
+		pdf_drop_obj(ctx, javascript);
+	fz_catch(ctx)
+	{
+		if (in_op)
+			pdf_abandon_operation(ctx, doc);
+		fz_rethrow(ctx);
+	}
+}
+
+void pdf_js_event_init(pdf_js *js, pdf_obj *target, const char *value, int willCommit)
+{
+	if (js)
+	{
+		js_getglobal(js->imp, "event");
+		{
+			js_pushboolean(js->imp, 1);
+			js_setproperty(js->imp, -2, "rc");
+
+			js_pushboolean(js->imp, willCommit);
+			js_setproperty(js->imp, -2, "willCommit");
+
+			js_getregistry(js->imp, "Field");
+			js_newuserdata(js->imp, "Field", pdf_keep_obj(js->ctx, target), field_finalize);
+			js_setproperty(js->imp, -2, "target");
+
+			js_pushstring(js->imp, value);
+			js_setproperty(js->imp, -2, "value");
+		}
+		js_pop(js->imp, 1);
+	}
+}
+
+int pdf_js_event_result(pdf_js *js)
+{
+	int rc = 1;
+	if (js)
+	{
+		js_getglobal(js->imp, "event");
+		js_getproperty(js->imp, -1, "rc");
+		rc = js_tryboolean(js->imp, -1, 1);
+		js_pop(js->imp, 2);
+	}
+	return rc;
+}
+
+int pdf_js_event_result_validate(pdf_js *js, char **newtext)
+{
+	int rc = 1;
+	*newtext = NULL;
+	if (js)
+	{
+		js_getglobal(js->imp, "event");
+		js_getproperty(js->imp, -1, "rc");
+		rc = js_tryboolean(js->imp, -1, 1);
+		js_pop(js->imp, 1);
+		if (rc)
+		{
+			js_getproperty(js->imp, -1, "value");
+			*newtext = fz_strdup(js->ctx, js_trystring(js->imp, -1, ""));
+			js_pop(js->imp, 1);
+		}
+		js_pop(js->imp, 1);
+	}
+	return rc;
+}
+
+void pdf_js_event_init_keystroke(pdf_js *js, pdf_obj *target, pdf_keystroke_event *evt)
+{
+	if (js)
+	{
+		pdf_js_event_init(js, target, evt->value, evt->willCommit);
+		js_getglobal(js->imp, "event");
+		{
+			js_pushstring(js->imp, evt->change);
+			js_setproperty(js->imp, -2, "change");
+			js_pushnumber(js->imp, evt->selStart);
+			js_setproperty(js->imp, -2, "selStart");
+			js_pushnumber(js->imp, evt->selEnd);
+			js_setproperty(js->imp, -2, "selEnd");
+		}
+		js_pop(js->imp, 1);
+	}
+}
+
+int pdf_js_event_result_keystroke(pdf_js *js, pdf_keystroke_event *evt)
+{
+	int rc = 1;
+	if (js)
+	{
+		js_getglobal(js->imp, "event");
+		{
+			js_getproperty(js->imp, -1, "rc");
+			rc = js_tryboolean(js->imp, -1, 1);
+			js_pop(js->imp, 1);
+			if (rc)
+			{
+				js_getproperty(js->imp, -1, "change");
+				evt->newChange = fz_strdup(js->ctx, js_trystring(js->imp, -1, ""));
+				js_pop(js->imp, 1);
+				js_getproperty(js->imp, -1, "value");
+				evt->newValue = fz_strdup(js->ctx, js_trystring(js->imp, -1, ""));
+				js_pop(js->imp, 1);
+				js_getproperty(js->imp, -1, "selStart");
+				evt->selStart = js_tryinteger(js->imp, -1, 0);
+				js_pop(js->imp, 1);
+				js_getproperty(js->imp, -1, "selEnd");
+				evt->selEnd = js_tryinteger(js->imp, -1, 0);
+				js_pop(js->imp, 1);
+			}
+		}
+		js_pop(js->imp, 1);
+	}
+	return rc;
+}
+
+char *pdf_js_event_value(pdf_js *js)
+{
+	char *value = NULL;
+	if (js)
+	{
+		js_getglobal(js->imp, "event");
+		js_getproperty(js->imp, -1, "value");
+		value = fz_strdup(js->ctx, js_trystring(js->imp, -1, "undefined"));
+		js_pop(js->imp, 2);
+	}
+	return value;
+}
+
+void pdf_js_execute(pdf_js *js, const char *name, const char *source, char **result)
+{
+	fz_context *ctx;
+	js_State *J;
+
+	if (!js)
+		return;
+
+	ctx = js->ctx;
+	J = js->imp;
+
+	pdf_begin_implicit_operation(ctx, js->doc);
+	fz_try(ctx)
+	{
+		if (js_ploadstring(J, name, source)) {
+			if (result)
+				*result = fz_strdup(ctx, js_trystring(J, -1, "Error"));
+			js_pop(J, 1);
+		} else {
+			js_pushundefined(J);
+			if (js_pcall(J, 0)) {
+				if (result)
+					*result = fz_strdup(ctx, js_trystring(J, -1, "Error"));
+				js_pop(J, 1);
+			} else {
+				if (result)
+					*result = fz_strdup(ctx, js_tryrepr(J, -1, "can't convert to string"));
+				js_pop(J, 1);
+			}
+		}
+		pdf_end_operation(ctx, js->doc);
+	}
+	fz_catch(ctx)
+	{
+		pdf_abandon_operation(ctx, js->doc);
+		fz_rethrow(ctx);
+	}
+}
+
+pdf_js_console *pdf_js_get_console(fz_context *ctx, pdf_document *doc)
+{
+	return (doc && doc->js) ? doc->js->console : NULL;
+}
+
+void pdf_js_set_console(fz_context *ctx, pdf_document *doc, pdf_js_console *console, void *user)
+{
+	if (doc->js)
+	{
+		if (doc->js->console && doc->js->console->drop)
+			doc->js->console->drop(doc->js->console, doc->js->console_user);
+
+		doc->js->console = console;
+		doc->js->console_user = user;
+	}
+}
+
+void pdf_enable_js(fz_context *ctx, pdf_document *doc)
+{
+	if (!doc->js)
+	{
+		doc->js = pdf_new_js(ctx, doc);
+		pdf_js_load_document_level(doc->js);
+	}
+}
+
+void pdf_disable_js(fz_context *ctx, pdf_document *doc)
+{
+	pdf_drop_js(ctx, doc->js);
+	doc->js = NULL;
+}
+
+int pdf_js_supported(fz_context *ctx, pdf_document *doc)
+{
+	return doc->js != NULL;
+}
+
+#else /* FZ_ENABLE_JS */
+
+void pdf_drop_js(fz_context *ctx, pdf_js *js) { }
+void pdf_enable_js(fz_context *ctx, pdf_document *doc) { }
+void pdf_disable_js(fz_context *ctx, pdf_document *doc) { }
+int pdf_js_supported(fz_context *ctx, pdf_document *doc) { return 0; }
+void pdf_js_event_init(pdf_js *js, pdf_obj *target, const char *value, int willCommit) { }
+void pdf_js_event_init_keystroke(pdf_js *js, pdf_obj *target, pdf_keystroke_event *evt) { }
+int pdf_js_event_result_keystroke(pdf_js *js, pdf_keystroke_event *evt) { return 1; }
+int pdf_js_event_result(pdf_js *js) { return 1; }
+char *pdf_js_event_value(pdf_js *js) { return ""; }
+void pdf_js_execute(pdf_js *js, const char *name, const char *source, char **result) { }
+int pdf_js_event_result_validate(pdf_js *js, char **newvalue) { *newvalue=NULL; return 1; }
+pdf_js_console *pdf_js_get_console(fz_context *ctx, pdf_document *doc) { return NULL; }
+void pdf_js_set_console(fz_context *ctx, pdf_document *doc, pdf_js_console *console, void *user) { }
+
+#endif /* FZ_ENABLE_JS */