Add initial Lua scripting support

This is preliminary. There are still tons of issues, and any aspect
of scripting may change in the future. I decided to merge this
(preliminary) work now because it makes it easier to develop it, not
because it's done. lua.rst is clear enough about it (plus some
sarcasm).

This requires linking to Lua. Lua has no official pkg-config file, but
there are distribution specific .pc files, all with different names.
Adding a non-pkg-config based configure test was considered, but we'd
rather not.

One major complication is that libquvi links against Lua too, and if
the Lua version is different from mpv's, you will get a crash as soon
as libquvi uses Lua. (libquvi by design always runs when a file is
opened.) I would consider this the problem of distros and whoever
builds mpv, but to make things easier for users, we add a terrible
runtime test to the configure script, which probes whether libquvi
will crash. This is disabled when cross-compiling, but in that case
we hope the user knows what he is doing.

1 files changed, 678 insertions, 0 deletions

diff --git a/mpvcore/mp_lua.c b/mpvcore/mp_lua.c
new file mode 100644
index 0000000000..ec63134673
--- /dev/null
+++ b/mpvcore/mp_lua.c
@@ -0,0 +1,678 @@
+#include <assert.h>
+#include <string.h>
+
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+
+#include "talloc.h"
+
+#include "mp_common.h"
+#include "mp_lua.h"
+#include "mp_core.h"
+#include "mp_msg.h"
+#include "m_property.h"
+#include "m_option.h"
+#include "command.h"
+#include "input/input.h"
+#include "sub/sub.h"
+#include "osdep/timer.h"
+#include "path.h"
+#include "bstr.h"
+
+// List of builtin modules and their contents as strings.
+// All these are generated from mpvcore/lua/*.lua
+static const char *builtin_lua_scripts[][2] = {
+    {"mp.defaults",
+#   include "lua/defaults.inc"
+    },
+    {"mp.assdraw",
+#   include "lua/assdraw.inc"
+    },
+    {0}
+};
+
+// Represents a loaded script. Each has its own Lua state.
+struct script_ctx {
+    const char *name;
+    lua_State *state;
+    struct mp_log *log;
+    struct MPContext *mpctx;
+};
+
+struct lua_ctx {
+    struct script_ctx **scripts;
+    int num_scripts;
+};
+
+static struct script_ctx *find_script(struct lua_ctx *lctx, const char *name)
+{
+    for (int n = 0; n < lctx->num_scripts; n++) {
+        if (strcmp(lctx->scripts[n]->name, name) == 0)
+            return lctx->scripts[n];
+    }
+    return NULL;
+}
+
+static struct script_ctx *get_ctx(lua_State *L)
+{
+    lua_getfield(L, LUA_REGISTRYINDEX, "ctx");
+    struct script_ctx *ctx = lua_touserdata(L, -1);
+    lua_pop(L, 1);
+    assert(ctx);
+    return ctx;
+}
+
+static struct MPContext *get_mpctx(lua_State *L)
+{
+    return get_ctx(L)->mpctx;
+}
+
+static int wrap_cpcall(lua_State *L)
+{
+    lua_CFunction fn = lua_touserdata(L, -1);
+    lua_pop(L, 1);
+    return fn(L);
+}
+
+// Call the given function fn under a Lua error handler (similar to lua_cpcall).
+// Pass the given number of args from the Lua stack to fn.
+// Returns 0 (and empty stack) on success.
+// Returns LUA_ERR[RUN|MEM|ERR] otherwise, with the error value on the stack.
+static int mp_cpcall(lua_State *L, lua_CFunction fn, int args)
+{
+    // Don't use lua_pushcfunction() - it allocates memory on Lua 5.1.
+    // Instead, emulate C closures by making wrap_cpcall call fn.
+    lua_pushlightuserdata(L, fn); // args... fn
+    // Will always succeed if mp_lua_init() set it up correctly.
+    lua_getfield(L, LUA_REGISTRYINDEX, "wrap_cpcall"); // args... fn wrap_cpcall
+    lua_insert(L, -(args + 2)); // wrap_cpcall args... fn
+    return lua_pcall(L, args + 1, 0, 0);
+}
+
+static void report_error(lua_State *L)
+{
+    const char *err = lua_tostring(L, -1);
+    mp_msg(MSGT_CPLAYER, MSGL_WARN, "[lua] Error: %s\n",
+           err ? err : "[unknown]");
+    lua_pop(L, 1);
+}
+
+static void add_functions(struct script_ctx *ctx);
+
+static char *script_name_from_filename(void *talloc_ctx, struct lua_ctx *lctx,
+                                       const char *fname)
+{
+    fname = mp_basename(fname);
+    if (fname[0] == '@')
+        fname += 1;
+    char *name = talloc_strdup(talloc_ctx, fname);
+    // Drop .lua extension
+    char *dot = strrchr(name, '.');
+    if (dot)
+        *dot = '\0';
+    // Turn it into a safe identifier - this is used with e.g. dispatching
+    // input via: "send scriptname ..."
+    for (int n = 0; name[n]; n++) {
+        char c = name[n];
+        if (!(c >= 'A' && c <= 'Z') && !(c >= 'a' && c <= 'z') &&
+            !(c >= '0' && c <= '9'))
+            name[n] = '_';
+    }
+    // Make unique (stupid but simple)
+    while (find_script(lctx, name))
+        name = talloc_strdup_append(name, "_");
+    return name;
+}
+
+static int load_file(struct script_ctx *ctx, const char *fname)
+{
+    int r = 0;
+    lua_State *L = ctx->state;
+    if (luaL_loadfile(L, fname) || lua_pcall(L, 0, 0, 0)) {
+        report_error(L);
+        r = -1;
+    }
+    assert(lua_gettop(L) == 0);
+    return r;
+}
+
+static int load_builtin(lua_State *L)
+{
+    const char *name = luaL_checkstring(L, 1);
+    for (int n = 0; builtin_lua_scripts[n][0]; n++) {
+        if (strcmp(name, builtin_lua_scripts[n][0]) == 0) {
+            if (luaL_loadstring(L, builtin_lua_scripts[n][1]))
+                lua_error(L);
+            lua_call(L, 0, 1);
+            return 1;
+        }
+    }
+    return 0;
+}
+
+// Execute "require " .. name
+static bool require(lua_State *L, const char *name)
+{
+    char buf[80];
+    // Lazy, but better than calling the "require" function manually
+    snprintf(buf, sizeof(buf), "require '%s'", name);
+    if (luaL_loadstring(L, buf) || lua_pcall(L, 0, 0, 0)) {
+        report_error(L);
+        return false;
+    }
+    return true;
+}
+
+static void mp_lua_load_script(struct MPContext *mpctx, const char *fname)
+{
+    struct lua_ctx *lctx = mpctx->lua_ctx;
+    struct script_ctx *ctx = talloc_ptrtype(NULL, ctx);
+    *ctx = (struct script_ctx) {
+        .mpctx = mpctx,
+        .name = script_name_from_filename(ctx, lctx, fname),
+    };
+    char *log_name = talloc_asprintf(ctx, "lua/%s", ctx->name);
+    ctx->log = mp_log_new(ctx, mpctx->log, log_name);
+
+    lua_State *L = ctx->state = luaL_newstate();
+    if (!L)
+        goto error_out;
+
+    // used by get_ctx()
+    lua_pushlightuserdata(L, ctx); // ctx
+    lua_setfield(L, LUA_REGISTRYINDEX, "ctx"); // -
+
+    lua_pushcfunction(L, wrap_cpcall); // closure
+    lua_setfield(L, LUA_REGISTRYINDEX, "wrap_cpcall"); // -
+
+    luaL_openlibs(L);
+
+    lua_newtable(L); // mp
+    lua_pushvalue(L, -1); // mp mp
+    lua_setglobal(L, "mp"); // mp
+
+    add_functions(ctx); // mp
+
+    lua_pushstring(L, ctx->name); // mp name
+    lua_setfield(L, -2, "script_name"); // mp
+
+    lua_pop(L, 1); // -
+
+    // Add a preloader for each builtin Lua module
+    lua_getglobal(L, "package"); // package
+    assert(lua_type(L, -1) == LUA_TTABLE);
+    lua_getfield(L, -1, "preload"); // package preload
+    assert(lua_type(L, -1) == LUA_TTABLE);
+    for (int n = 0; builtin_lua_scripts[n][0]; n++) {
+        lua_pushcfunction(L, load_builtin); // package preload load_builtin
+        lua_setfield(L, -2, builtin_lua_scripts[n][0]);
+    }
+    lua_pop(L, 2); // -
+
+    assert(lua_gettop(L) == 0);
+
+    if (!require(L, "mp.defaults")) {
+        report_error(L);
+        goto error_out;
+    }
+
+    assert(lua_gettop(L) == 0);
+
+    if (fname[0] == '@') {
+        if (!require(L, fname))
+            goto error_out;
+    } else {
+        if (load_file(ctx, fname) < 0)
+            goto error_out;
+    }
+
+    MP_TARRAY_APPEND(lctx, lctx->scripts, lctx->num_scripts, ctx);
+    return;
+
+error_out:
+    if (ctx->state)
+        lua_close(ctx->state);
+    talloc_free(ctx);
+}
+
+static void kill_script(struct script_ctx *ctx)
+{
+    if (!ctx)
+        return;
+    struct lua_ctx *lctx = ctx->mpctx->lua_ctx;
+    lua_close(ctx->state);
+    for (int n = 0; n < lctx->num_scripts; n++) {
+        if (lctx->scripts[n] == ctx) {
+            MP_TARRAY_REMOVE_AT(lctx->scripts, lctx->num_scripts, n);
+            break;
+        }
+    }
+    talloc_free(ctx);
+}
+
+static const char *log_level[] = {
+    [MSGL_FATAL] = "fatal",
+    [MSGL_ERR] = "error",
+    [MSGL_WARN] = "warn",
+    [MSGL_INFO] = "info",
+    [MSGL_V] = "verbose",
+    [MSGL_DBG2] = "debug",
+};
+
+static int script_log(lua_State *L)
+{
+    struct script_ctx *ctx = get_ctx(L);
+
+    const char *level = luaL_checkstring(L, 1);
+    int msgl = -1;
+    for (int n = 0; n < MP_ARRAY_SIZE(log_level); n++) {
+        if (log_level[n] && strcasecmp(log_level[n], level) == 0) {
+            msgl = n;
+            break;
+        }
+    }
+    if (msgl < 0)
+        luaL_error(L, "Invalid log level '%s'", level);
+
+    int last = lua_gettop(L);
+    lua_getglobal(L, "tostring"); // args... tostring
+    for (int i = 2; i <= last; i++) {
+        lua_pushvalue(L, -1); // args... tostring tostring
+        lua_pushvalue(L, i); // args... tostring tostring args[i]
+        lua_call(L, 1, 1); // args... tostring str
+        const char *s = lua_tostring(L, -1);
+        if (s == NULL)
+            return luaL_error(L, "Invalid argument");
+        mp_msg_log(ctx->log, msgl, "%s%s", s, i > 0 ? " " : "");
+        lua_pop(L, 1);  // args... tostring
+    }
+    mp_msg_log(ctx->log, msgl, "\n");
+
+    return 0;
+}
+
+static int script_find_config_file(lua_State *L)
+{
+    const char *s = luaL_checkstring(L, 1);
+    char *path = mp_find_user_config_file(s);
+    if (path) {
+        lua_pushstring(L, path);
+    } else {
+        lua_pushnil(L);
+    }
+    talloc_free(path);
+    return 1;
+}
+
+static int run_event(lua_State *L)
+{
+    lua_getglobal(L, "mp_event"); // name arg mp_event
+    if (lua_isnil(L, -1))
+        return 0;
+    lua_insert(L, -3); // mp_event name arg
+    lua_call(L, 2, 0);
+    return 0;
+}
+
+void mp_lua_event(struct MPContext *mpctx, const char *name, const char *arg)
+{
+    // There is no proper subscription mechanism yet, so all scripts get it.
+    struct lua_ctx *lctx = mpctx->lua_ctx;
+    for (int n = 0; n < lctx->num_scripts; n++) {
+        struct script_ctx *ctx = lctx->scripts[n];
+        lua_State *L = ctx->state;
+        lua_pushstring(L, name);
+        if (arg) {
+            lua_pushstring(L, arg);
+        } else {
+            lua_pushnil(L);
+        }
+        if (mp_cpcall(L, run_event, 2) != 0)
+            report_error(L);
+    }
+}
+
+static int run_script_dispatch(lua_State *L)
+{
+    int id = lua_tointeger(L, 1);
+    const char *event = lua_tostring(L, 2);
+    lua_getglobal(L, "mp_script_dispatch");
+    if (lua_isnil(L, -1))
+        return 0;
+    lua_pushinteger(L, id);
+    lua_pushstring(L, event);
+    lua_call(L, 2, 0);
+    return 0;
+}
+
+void mp_lua_script_dispatch(struct MPContext *mpctx, char *script_name,
+                            int id, char *event)
+{
+    struct script_ctx *ctx = find_script(mpctx->lua_ctx, script_name);
+    if (!ctx) {
+        mp_msg(MSGT_CPLAYER, MSGL_V,
+               "Can't find script '%s' when handling input.\n", script_name);
+        return;
+    }
+    lua_State *L = ctx->state;
+    lua_pushinteger(L, id);
+    lua_pushstring(L, event);
+    if (mp_cpcall(L, run_script_dispatch, 2) != 0)
+        report_error(L);
+}
+
+static int script_send_command(lua_State *L)
+{
+    struct MPContext *mpctx = get_mpctx(L);
+    const char *s = luaL_checkstring(L, 1);
+
+    mp_cmd_t *cmd = mp_input_parse_cmd(bstr0((char*)s), "<lua>");
+    if (!cmd)
+        luaL_error(L, "error parsing command");
+    mp_input_queue_cmd(mpctx->input, cmd);
+
+    return 0;
+}
+
+static int script_property_list(lua_State *L)
+{
+    const struct m_option *props = mp_get_property_list();
+    lua_newtable(L);
+    for (int i = 0; props[i].name; i++) {
+        lua_pushinteger(L, i + 1);
+        lua_pushstring(L, props[i].name);
+        lua_settable(L, -3);
+    }
+    return 1;
+}
+
+static int script_property_string(lua_State *L)
+{
+    const struct m_option *props = mp_get_property_list();
+    struct MPContext *mpctx = get_mpctx(L);
+    const char *name = luaL_checkstring(L, 1);
+    int type = lua_tointeger(L, lua_upvalueindex(1))
+               ? M_PROPERTY_PRINT : M_PROPERTY_GET_STRING;
+
+    char *result = NULL;
+    if (m_property_do(props, name, type, &result, mpctx) >= 0 && result) {
+        lua_pushstring(L, result);
+        talloc_free(result);
+        return 1;
+    }
+    if (type == M_PROPERTY_PRINT) {
+        lua_pushstring(L, "");
+        return 1;
+    }
+    return 0;
+}
+
+static int script_set_osd_ass(lua_State *L)
+{
+    struct MPContext *mpctx = get_mpctx(L);
+    int res_x = luaL_checkinteger(L, 1);
+    int res_y = luaL_checkinteger(L, 2);
+    const char *text = luaL_checkstring(L, 3);
+    if (!mpctx->osd->external ||
+        strcmp(mpctx->osd->external, text) != 0 ||
+        mpctx->osd->external_res_x != res_x ||
+        mpctx->osd->external_res_y != res_y)
+    {
+        talloc_free(mpctx->osd->external);
+        mpctx->osd->external = talloc_strdup(mpctx->osd, text);
+        mpctx->osd->external_res_x = res_x;
+        mpctx->osd->external_res_y = res_y;
+        osd_changed(mpctx->osd, OSDTYPE_EXTERNAL);
+    }
+    return 0;
+}
+
+static int script_get_osd_resolution(lua_State *L)
+{
+    struct MPContext *mpctx = get_mpctx(L);
+    int w, h;
+    osd_object_get_resolution(mpctx->osd, mpctx->osd->objs[OSDTYPE_EXTERNAL],
+                              &w, &h);
+    lua_pushnumber(L, w);
+    lua_pushnumber(L, h);
+    return 2;
+}
+
+static int script_get_screen_size(lua_State *L)
+{
+    struct MPContext *mpctx = get_mpctx(L);
+    struct osd_object *obj = mpctx->osd->objs[OSDTYPE_EXTERNAL];
+    double aspect = 1.0 * obj->vo_res.w / MPMAX(obj->vo_res.h, 1) /
+                    obj->vo_res.display_par;
+    lua_pushnumber(L, obj->vo_res.w);
+    lua_pushnumber(L, obj->vo_res.h);
+    lua_pushnumber(L, aspect);
+    return 3;
+}
+
+static int script_get_mouse_pos(lua_State *L)
+{
+    struct MPContext *mpctx = get_mpctx(L);
+    float px, py;
+    mp_get_osd_mouse_pos(mpctx, &px, &py);
+    double sw, sh;
+    osd_object_get_scale_factor(mpctx->osd, mpctx->osd->objs[OSDTYPE_EXTERNAL],
+                                &sw, &sh);
+    lua_pushnumber(L, px * sw);
+    lua_pushnumber(L, py * sh);
+    return 2;
+}
+
+static int script_get_timer(lua_State *L)
+{
+    lua_pushnumber(L, mp_time_sec());
+    return 1;
+}
+
+static int script_get_chapter_list(lua_State *L)
+{
+    struct MPContext *mpctx = get_mpctx(L);
+    lua_newtable(L); // list
+    int num = get_chapter_count(mpctx);
+    for (int n = 0; n < num; n++) {
+        double time = chapter_start_time(mpctx, n);
+        char *name = chapter_display_name(mpctx, n);
+        lua_newtable(L); // list ch
+        lua_pushnumber(L, time); // list ch time
+        lua_setfield(L, -2, "time"); // list ch
+        lua_pushstring(L, name); // list ch name
+        lua_setfield(L, -2, "name"); // list ch
+        lua_pushinteger(L, n + 1); // list ch n1
+        lua_insert(L, -2); // list n1 ch
+        lua_settable(L, -3); // list
+        talloc_free(name);
+    }
+    return 1;
+}
+
+static const char *stream_type(enum stream_type t)
+{
+    switch (t) {
+    case STREAM_VIDEO: return "video";
+    case STREAM_AUDIO: return "audio";
+    case STREAM_SUB:   return "sub";
+    default:           return "unknown";
+    }
+}
+
+static int script_get_track_list(lua_State *L)
+{
+    struct MPContext *mpctx = get_mpctx(L);
+    lua_newtable(L); // list
+    for (int n = 0; n < mpctx->num_tracks; n++) {
+        struct track *track = mpctx->tracks[n];
+        lua_newtable(L); // list track
+
+        lua_pushstring(L, stream_type(track->type));
+        lua_setfield(L, -2, "type");
+        lua_pushinteger(L, track->user_tid);
+        lua_setfield(L, -2, "id");
+        lua_pushboolean(L, track->default_track);
+        lua_setfield(L, -2, "default");
+        lua_pushboolean(L, track->attached_picture);
+        lua_setfield(L, -2, "attached_picture");
+        if (track->lang) {
+            lua_pushstring(L, track->lang);
+            lua_setfield(L, -2, "language");
+        }
+        if (track->title) {
+            lua_pushstring(L, track->title);
+            lua_setfield(L, -2, "title");
+        }
+        lua_pushboolean(L, track->is_external);
+        lua_setfield(L, -2, "external");
+        if (track->external_filename) {
+            lua_pushstring(L, track->external_filename);
+            lua_setfield(L, -2, "external_filename");
+        }
+        lua_pushboolean(L, track->auto_loaded);
+        lua_setfield(L, -2, "auto_loaded");
+
+        lua_pushinteger(L, n + 1); // list track n1
+        lua_insert(L, -2); // list n1 track
+        lua_settable(L, -3); // list
+    }
+    return 1;
+}
+
+static int script_input_define_section(lua_State *L)
+{
+    struct MPContext *mpctx = get_mpctx(L);
+    char *section = (char *)luaL_checkstring(L, 1);
+    char *contents = (char *)luaL_checkstring(L, 2);
+    mp_input_define_section(mpctx->input, section, "<script>", contents, true);
+    return 0;
+}
+
+static int script_input_enable_section(lua_State *L)
+{
+    struct MPContext *mpctx = get_mpctx(L);
+    char *section = (char *)luaL_checkstring(L, 1);
+    char *sflags = (char *)luaL_optstring(L, 2, "");
+    bstr bflags = bstr0(sflags);
+    int flags = 0;
+    while (bflags.len) {
+        bstr val;
+        bstr_split_tok(bflags, "|", &val, &bflags);
+        if (bstr_equals0(val, "allow-hide-cursor")) {
+            flags |= MP_INPUT_ALLOW_HIDE_CURSOR;
+        } else if (bstr_equals0(val, "allow-vo-dragging")) {
+            flags |= MP_INPUT_ALLOW_VO_DRAGGING;
+        } else if (bstr_equals0(val, "exclusive")) {
+            flags |= MP_INPUT_EXCLUSIVE;
+        } else {
+            luaL_error(L, "invalid flag: '%.*s'", BSTR_P(val));
+        }
+    }
+    mp_input_enable_section(mpctx->input, section, flags);
+    return 0;
+}
+
+static int script_input_disable_section(lua_State *L)
+{
+    struct MPContext *mpctx = get_mpctx(L);
+    char *section = (char *)luaL_checkstring(L, 1);
+    mp_input_disable_section(mpctx->input, section);
+    return 0;
+}
+
+static int script_input_set_section_mouse_area(lua_State *L)
+{
+    struct MPContext *mpctx = get_mpctx(L);
+
+    double sw, sh;
+    struct osd_object *obj = mpctx->osd->objs[OSDTYPE_EXTERNAL];
+    osd_object_get_scale_factor(mpctx->osd, obj, &sw, &sh);
+
+    char *section = (char *)luaL_checkstring(L, 1);
+    int x0 = luaL_checkinteger(L, 2) / sw;
+    int y0 = luaL_checkinteger(L, 3) / sh;
+    int x1 = luaL_checkinteger(L, 4) / sw;
+    int y1 = luaL_checkinteger(L, 5) / sh;
+    mp_input_set_section_mouse_area(mpctx->input, section, x0, y0, x1, y1);
+    return 0;
+}
+
+static int script_format_time(lua_State *L)
+{
+    double t = luaL_checknumber(L, 1);
+    const char *fmt = luaL_optstring(L, 2, "%H:%M:%S");
+    char *r = mp_format_time_fmt(fmt, t);
+    if (!r)
+        luaL_error(L, "Invalid time format string '%s'", fmt);
+    lua_pushstring(L, r);
+    talloc_free(r);
+    return 1;
+}
+
+struct fn_entry {
+    const char *name;
+    int (*fn)(lua_State *L);
+};
+
+#define FN_ENTRY(name) {#name, script_ ## name}
+
+static struct fn_entry fn_list[] = {
+    FN_ENTRY(log),
+    FN_ENTRY(find_config_file),
+    FN_ENTRY(send_command),
+    FN_ENTRY(property_list),
+    FN_ENTRY(set_osd_ass),
+    FN_ENTRY(get_osd_resolution),
+    FN_ENTRY(get_screen_size),
+    FN_ENTRY(get_mouse_pos),
+    FN_ENTRY(get_timer),
+    FN_ENTRY(get_chapter_list),
+    FN_ENTRY(get_track_list),
+    FN_ENTRY(input_define_section),
+    FN_ENTRY(input_enable_section),
+    FN_ENTRY(input_disable_section),
+    FN_ENTRY(input_set_section_mouse_area),
+    FN_ENTRY(format_time),
+};
+
+// On stack: mp table
+static void add_functions(struct script_ctx *ctx)
+{
+    lua_State *L = ctx->state;
+
+    for (int n = 0; n < MP_ARRAY_SIZE(fn_list); n++) {
+        lua_pushcfunction(L, fn_list[n].fn);
+        lua_setfield(L, -2, fn_list[n].name);
+    }
+
+    lua_pushinteger(L, 0);
+    lua_pushcclosure(L, script_property_string, 1);
+    lua_setfield(L, -2, "property_get");
+
+    lua_pushinteger(L, 1);
+    lua_pushcclosure(L, script_property_string, 1);
+    lua_setfield(L, -2, "property_get_string");
+}
+
+void mp_lua_init(struct MPContext *mpctx)
+{
+    mpctx->lua_ctx = talloc_zero(NULL, struct lua_ctx);
+    // Load scripts from options
+    char **files = mpctx->opts->lua_files;
+    for (int n = 0; files && files[n]; n++) {
+        if (files[n][0])
+            mp_lua_load_script(mpctx, files[n]);
+    }
+}
+
+void mp_lua_uninit(struct MPContext *mpctx)
+{
+    if (mpctx->lua_ctx) {
+        while (mpctx->lua_ctx->num_scripts)
+            kill_script(mpctx->lua_ctx->scripts[0]);
+        talloc_free(mpctx->lua_ctx);
+        mpctx->lua_ctx = NULL;
+    }
+}