Ensure iconv contexts get cleaned up, also test it

2 files changed, 63 insertions, 7 deletions

diff --git a/luxio.c b/luxio.c
index 043716f..c1566cd 100644
--- a/luxio.c
+++ b/luxio.c
@@ -3703,6 +3703,51 @@ luxio_LOG_MASK(lua_State *L)
 	return 1;
 }
 
+/*** Character set conversion.
+@section iconv
+*/
+
+#define LUXIO_ICONV_METATABLE "luxio.iconv"
+
+static int
+luxio__iconv_gc(lua_State *L)
+{
+	iconv_t *ic = (iconv_t*)(lua_touserdata(L, 1));
+	if (*ic != NULL && *ic != (iconv_t)(-1)) {
+		iconv_close(*ic);
+		*ic = NULL;
+	}
+	return 0;
+}
+
+static int
+luxio__iconv_tostring(lua_State *L)
+{
+	iconv_t *ic = (iconv_t*)(lua_touserdata(L, 1));
+	lua_pushfstring(L, "<iconv %p>", *ic);
+	return 1;
+}
+
+static iconv_t*
+luxio__create_iconv(lua_State *L)
+{
+	iconv_t *r = lua_newuserdata(L, sizeof(iconv_t));
+	int create = luaL_newmetatable(L, LUXIO_ICONV_METATABLE);
+
+	if (create != 0) {
+		lua_pushcfunction(L, luxio__iconv_gc);
+		lua_setfield(L, -2, "__gc");
+		lua_pushcfunction(L, luxio__iconv_tostring);
+		lua_setfield(L, -2, "__tostring");
+	}
+
+	*r = NULL;
+
+	lua_setmetatable(L, -2);
+
+	return r;
+}
+
 /*** Allocate descriptor for character set conversion.
 @tparam string tocode
 @tparam string fromcode
@@ -3715,16 +3760,18 @@ luxio_iconv_open(lua_State *L)
 {
 	const char *tocode = luaL_checkstring(L, 1);
 	const char *fromcode = luaL_checkstring(L, 2);
-	iconv_t r = iconv_open(tocode, fromcode);
+	iconv_t *r = luxio__create_iconv(L);
 
-	if (r == (iconv_t)-1) {
+	*r = iconv_open(tocode, fromcode);
+
+	if (*r == (iconv_t)-1) {
 		lua_pushnumber(L, -1);
 		lua_pushnumber(L, errno);
 		return 2;
-	} else {
-		lua_pushlightuserdata(L, (void *)r);
-		return 1;
 	}
+
+	/* On the top of the stack is the iconv userdata */
+	return 1;
 }
 
 /*** Close a previously-allocated iconv descriptor.
@@ -3736,7 +3783,10 @@ luxio_iconv_open(lua_State *L)
 static int
 luxio_iconv_close(lua_State *L)
 {
-	iconv_t c = (iconv_t)lua_touserdata(L, 1);
+	iconv_t *_c = (iconv_t*)lua_touserdata(L, 1);
+	iconv_t c = *_c;
+
+	*_c = NULL;
 
 	if (iconv_close(c) == -1) {
 		lua_pushnumber(L, -1);
@@ -3763,7 +3813,8 @@ luxio_iconv(lua_State *L)
 {
 	/* based on Alexandre Erwin Ittner <alexandre@ittner.com.br>'s code */
 	/* either returns completed string, or -1, errno, partial result */
-    iconv_t cd = (iconv_t)lua_touserdata(L, 1);
+    iconv_t *_cd = (iconv_t*)lua_touserdata(L, 1);
+    iconv_t cd = *_cd;
     size_t ibleft;
     char *inbuf = (char* )luaL_checklstring(L, 2, &ibleft);
     char outbufs[ICONV_BUF_SIZE];
diff --git a/tests/test-iconv.lua b/tests/test-iconv.lua
new file mode 100644
index 0000000..6a14ac1
--- /dev/null
+++ b/tests/test-iconv.lua
@@ -0,0 +1,5 @@
+luxio = require 'luxio'
+
+cd = luxio.iconv_open("UTF-8", "ISO-8859-1")
+assert(luxio.iconv(cd, "\163") == "£")
+luxio.iconv_close(cd)