[syslinux:master] lua: make the file operations methods

[syslinux-bot for Ferenc Wágner]

Commit-ID:  be151c64e724d8a8d250b9a2dd9426a584ed76bc
Gitweb:     http://www.syslinux.org/commit/be151c64e724d8a8d250b9a2dd9426a584ed76bc
Author:     Ferenc Wágner <wferi at niif.hu>
AuthorDate: Fri, 10 Oct 2014 11:29:12 +0200
Committer:  Ferenc Wágner <wferi at niif.hu>
CommitDate: Sun, 12 Oct 2014 10:13:14 +0200

lua: make the file operations methods

This also enables manual unloading of files by callig f:__gc().

Signed-off-by: Ferenc Wágner <wferi at niif.hu>

---
 com32/lua/src/syslinux.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/com32/lua/src/syslinux.c b/com32/lua/src/syslinux.c
index 22fd0df..6b57144 100644
--- a/com32/lua/src/syslinux.c
+++ b/com32/lua/src/syslinux.c
@@ -262,6 +262,8 @@ static int sl_unloadfile (lua_State *L)
 
     free (file->name);
     free (file->data);
+    /* the __gc method may also be (repeatedly) called before garbage collection, so: */
+    file->name = file->data = NULL;
     return 0;
 }
 
@@ -423,8 +425,6 @@ static const luaL_Reg syslinuxlib[] = {
     {"sleep", sl_sleep},
     {"msleep", sl_msleep},
     {"loadfile", sl_loadfile},
-    {"filesize", sl_filesize},
-    {"filename", sl_filename},
     {"initramfs_init", sl_initramfs_init},
     {"initramfs_load_archive", sl_initramfs_load_archive},
     {"initramfs_add_file", sl_initramfs_add_file},
@@ -441,6 +441,8 @@ static const luaL_Reg syslinuxlib[] = {
 
 static const luaL_Reg file_methods[] = {
     {"__gc", sl_unloadfile},
+    {"name", sl_filename},
+    {"size", sl_filesize},
     {NULL, NULL}
 };
 
@@ -450,6 +452,9 @@ LUALIB_API int luaopen_syslinux(lua_State * L)
 {
 
     luaL_newmetatable(L, SYSLINUX_FILE);
+    lua_pushstring (L, "__index");
+    lua_pushvalue (L, -2);
+    lua_settable (L, -3);
     luaL_setfuncs (L, file_methods, 0);
 
     luaL_newlib(L, syslinuxlib);