--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/mujs/jsstate.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,334 @@
+#include "jsi.h"
+
+#include <assert.h>
+#include <errno.h>
+
+static int js_ptry(js_State *J) {
+	if (J->trytop == JS_TRYLIMIT) {
+		J->stack[J->top].t.type = JS_TLITSTR;
+		J->stack[J->top].u.litstr = "exception stack overflow";
+		++J->top;
+		return 1;
+	}
+	return 0;
+}
+
+static void *js_defaultalloc(void *actx, void *ptr, int size)
+{
+	if (size == 0) {
+		free(ptr);
+		return NULL;
+	}
+	return realloc(ptr, (size_t)size);
+}
+
+static void js_defaultreport(js_State *J, const char *message)
+{
+	fputs(message, stderr);
+	fputc('\n', stderr);
+}
+
+static void js_defaultpanic(js_State *J)
+{
+	js_report(J, "uncaught exception");
+	/* return to javascript to abort */
+}
+
+int js_ploadstring(js_State *J, const char *filename, const char *source)
+{
+	if (js_ptry(J))
+		return 1;
+	if (js_try(J))
+		return 1;
+	js_loadstring(J, filename, source);
+	js_endtry(J);
+	return 0;
+}
+
+int js_ploadfile(js_State *J, const char *filename)
+{
+	if (js_ptry(J))
+		return 1;
+	if (js_try(J))
+		return 1;
+	js_loadfile(J, filename);
+	js_endtry(J);
+	return 0;
+}
+
+const char *js_trystring(js_State *J, int idx, const char *error)
+{
+	const char *s;
+	if (js_ptry(J)) {
+		js_pop(J, 1);
+		return error;
+	}
+	if (js_try(J)) {
+		js_pop(J, 1);
+		return error;
+	}
+	s = js_tostring(J, idx);
+	js_endtry(J);
+	return s;
+}
+
+double js_trynumber(js_State *J, int idx, double error)
+{
+	double v;
+	if (js_ptry(J)) {
+		js_pop(J, 1);
+		return error;
+	}
+	if (js_try(J)) {
+		js_pop(J, 1);
+		return error;
+	}
+	v = js_tonumber(J, idx);
+	js_endtry(J);
+	return v;
+}
+
+int js_tryinteger(js_State *J, int idx, int error)
+{
+	int v;
+	if (js_ptry(J)) {
+		js_pop(J, 1);
+		return error;
+	}
+	if (js_try(J)) {
+		js_pop(J, 1);
+		return error;
+	}
+	v = js_tointeger(J, idx);
+	js_endtry(J);
+	return v;
+}
+
+int js_tryboolean(js_State *J, int idx, int error)
+{
+	int v;
+	if (js_ptry(J)) {
+		js_pop(J, 1);
+		return error;
+	}
+	if (js_try(J)) {
+		js_pop(J, 1);
+		return error;
+	}
+	v = js_toboolean(J, idx);
+	js_endtry(J);
+	return v;
+}
+
+static void js_loadstringx(js_State *J, const char *filename, const char *source, int iseval)
+{
+	js_Ast *P;
+	js_Function *F;
+
+	if (js_try(J)) {
+		jsP_freeparse(J);
+		js_throw(J);
+	}
+
+	P = jsP_parse(J, filename, source);
+	F = jsC_compilescript(J, P, iseval ? J->strict : J->default_strict);
+	jsP_freeparse(J);
+	js_newscript(J, F, iseval ? (J->strict ? J->E : NULL) : J->GE);
+
+	js_endtry(J);
+}
+
+void js_loadeval(js_State *J, const char *filename, const char *source)
+{
+	js_loadstringx(J, filename, source, 1);
+}
+
+void js_loadstring(js_State *J, const char *filename, const char *source)
+{
+	js_loadstringx(J, filename, source, 0);
+}
+
+void js_loadfile(js_State *J, const char *filename)
+{
+	FILE *f;
+	char *s, *p;
+	int n, t;
+
+	f = fopen(filename, "rb");
+	if (!f) {
+		js_error(J, "cannot open file '%s': %s", filename, strerror(errno));
+	}
+
+	if (fseek(f, 0, SEEK_END) < 0) {
+		fclose(f);
+		js_error(J, "cannot seek in file '%s': %s", filename, strerror(errno));
+	}
+
+	n = ftell(f);
+	if (n < 0) {
+		fclose(f);
+		js_error(J, "cannot tell in file '%s': %s", filename, strerror(errno));
+	}
+
+	if (fseek(f, 0, SEEK_SET) < 0) {
+		fclose(f);
+		js_error(J, "cannot seek in file '%s': %s", filename, strerror(errno));
+	}
+
+	if (js_try(J)) {
+		fclose(f);
+		js_throw(J);
+	}
+	s = js_malloc(J, n + 1); /* add space for string terminator */
+	js_endtry(J);
+
+	t = fread(s, 1, (size_t)n, f);
+	if (t != n) {
+		js_free(J, s);
+		fclose(f);
+		js_error(J, "cannot read data from file '%s': %s", filename, strerror(errno));
+	}
+
+	s[n] = 0; /* zero-terminate string containing file data */
+
+	if (js_try(J)) {
+		js_free(J, s);
+		fclose(f);
+		js_throw(J);
+	}
+
+	/* skip first line if it starts with "#!" */
+	p = s;
+	if (p[0] == '#' && p[1] == '!') {
+		p += 2;
+		while (*p && *p != '\n')
+			++p;
+	}
+
+	js_loadstring(J, filename, p);
+
+	js_free(J, s);
+	fclose(f);
+	js_endtry(J);
+}
+
+int js_dostring(js_State *J, const char *source)
+{
+	if (js_ptry(J)) {
+		js_report(J, "exception stack overflow");
+		js_pop(J, 1);
+		return 1;
+	}
+	if (js_try(J)) {
+		js_report(J, js_trystring(J, -1, "Error"));
+		js_pop(J, 1);
+		return 1;
+	}
+	js_loadstring(J, "[string]", source);
+	js_pushundefined(J);
+	js_call(J, 0);
+	js_pop(J, 1);
+	js_endtry(J);
+	return 0;
+}
+
+int js_dofile(js_State *J, const char *filename)
+{
+	if (js_ptry(J)) {
+		js_report(J, "exception stack overflow");
+		js_pop(J, 1);
+		return 1;
+	}
+	if (js_try(J)) {
+		js_report(J, js_trystring(J, -1, "Error"));
+		js_pop(J, 1);
+		return 1;
+	}
+	js_loadfile(J, filename);
+	js_pushundefined(J);
+	js_call(J, 0);
+	js_pop(J, 1);
+	js_endtry(J);
+	return 0;
+}
+
+js_Panic js_atpanic(js_State *J, js_Panic panic)
+{
+	js_Panic old = J->panic;
+	J->panic = panic;
+	return old;
+}
+
+void js_report(js_State *J, const char *message)
+{
+	if (J->report)
+		J->report(J, message);
+}
+
+void js_setreport(js_State *J, js_Report report)
+{
+	J->report = report;
+}
+
+void js_setcontext(js_State *J, void *uctx)
+{
+	J->uctx = uctx;
+}
+
+void *js_getcontext(js_State *J)
+{
+	return J->uctx;
+}
+
+js_State *js_newstate(js_Alloc alloc, void *actx, int flags)
+{
+	js_State *J;
+
+	assert(sizeof(js_Value) == 16);
+	assert(soffsetof(js_Value, t.type) == 15);
+
+	if (!alloc)
+		alloc = js_defaultalloc;
+
+	J = alloc(actx, NULL, sizeof *J);
+	if (!J)
+		return NULL;
+	memset(J, 0, sizeof(*J));
+	J->actx = actx;
+	J->alloc = alloc;
+
+	if (flags & JS_STRICT)
+		J->strict = J->default_strict = 1;
+
+	J->trace[0].name = "-top-";
+	J->trace[0].file = "native";
+	J->trace[0].line = 0;
+
+	J->report = js_defaultreport;
+	J->panic = js_defaultpanic;
+
+	J->stack = alloc(actx, NULL, JS_STACKSIZE * sizeof *J->stack);
+	if (!J->stack) {
+		alloc(actx, J, 0);
+		return NULL;
+	}
+
+	J->gcmark = 1;
+	J->nextref = 0;
+	J->gcthresh = 0; /* reaches stability within ~ 2-5 GC cycles */
+
+	if (js_try(J)) {
+		js_freestate(J);
+		return NULL;
+	}
+
+	J->R = jsV_newobject(J, JS_COBJECT, NULL);
+	J->G = jsV_newobject(J, JS_COBJECT, NULL);
+	J->E = jsR_newenvironment(J, J->G, NULL);
+	J->GE = J->E;
+
+	jsB_init(J);
+
+	js_endtry(J);
+	return J;
+}