bug: Fix version incompatibility

Even between minor versions, Lua simply removes or renames functions.

src/lua_libpulse_glib/context.c

@@ -1,6 +1,7 @@
 #include "context.h"
 
 #include "pulseaudio.h"
+#include "lua_util.h"
 
 #include <pulse/context.h>
 #include <pulse/error.h>
@@ -196,7 +197,7 @@ int context_subscribe(lua_State* L) {
     lua_pa_context* ctx = luaL_checkudata(L, 1, LUA_PA_CONTEXT);
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
-    size_t pos = lua_objlen(ctx->event_callback_data->L, 1) + 1;
+    size_t pos = lua_rawlen(ctx->event_callback_data->L, 1) + 1;
     // Duplicate the callback function, so we can move it over to the other thread
     lua_pushvalue(L, 2);
     lua_xmove(L, ctx->event_callback_data->L, 1);
@@ -211,7 +212,7 @@ int context_unsubscribe(lua_State* L) {
     lua_pa_context* ctx = luaL_checkudata(L, 1, LUA_PA_CONTEXT);
     lua_State* thread_L = ctx->event_callback_data->L;
     size_t pos = 0;
-    size_t len = lua_objlen(thread_L, 1);
+    size_t len = lua_rawlen(thread_L, 1);
 
     if (len == 0) {
         return 0;

src/lua_libpulse_glib/introspection.c

@@ -55,7 +55,7 @@ void sink_info_callback(pa_context* c, const pa_sink_info* info, int eol, void*
 
     if (data->is_list) {
         if (!eol) {
-            int i = lua_objlen(L, 2);
+            int i = lua_rawlen(L, 2);
             lua_pushinteger(L, i + 1);
             sink_info_to_lua(L, info);
             lua_settable(L, 2);
@@ -446,7 +446,7 @@ void source_info_callback(pa_context* c, const pa_source_info* info, int eol, vo
 
     if (data->is_list) {
         if (!eol) {
-            int i = lua_objlen(L, 2);
+            int i = lua_rawlen(L, 2);
             lua_pushinteger(L, i + 1);
             source_info_to_lua(L, info);
             lua_settable(L, 2);
@@ -827,7 +827,7 @@ void sink_input_info_callback(pa_context* c, const pa_sink_input_info* info, int
 
     if (data->is_list) {
         if (!eol) {
-            int i = lua_objlen(L, 2);
+            int i = lua_rawlen(L, 2);
             lua_pushinteger(L, i + 1);
             sink_input_info_to_lua(L, info);
             lua_settable(L, 2);
@@ -1100,7 +1100,7 @@ void source_output_info_callback(pa_context* c, const pa_source_output_info* inf
 
     if (data->is_list) {
         if (!eol) {
-            int i = lua_objlen(L, 2);
+            int i = lua_rawlen(L, 2);
             lua_pushinteger(L, i + 1);
             source_output_info_to_lua(L, info);
             lua_settable(L, 2);

src/lua_libpulse_glib/lua_util.h

@@ -6,6 +6,13 @@
 
 #define LUA_MOD_EXPORT extern
 
+#if LUA_VERSION_NUM <= 501
+#define lua_rawlen lua_objlen
+#endif
+
+#if LUA_VERSION_NUM > 501
+#define lua_equal(L, i1, i2) lua_compare(L, i1, i2, LUA_OPEQ)
+#endif
 
 typedef struct luaU_enumfield {
     const char* name;

src/lua_libpulse_glib/volume.c

@@ -35,7 +35,7 @@ int volume_to_lua(lua_State* L, const pa_cvolume* pa_volume) {
 pa_cvolume* volume_from_lua(lua_State* L, int index) {
     switch (lua_type(L, index)) {
     case LUA_TTABLE: {
-        uint8_t channels = (uint8_t) lua_objlen(L, index);
+        uint8_t channels = (uint8_t) lua_rawlen(L, index);
         if (channels > PA_CHANNELS_MAX) {
             channels = PA_CHANNELS_MAX;
         }
@@ -82,7 +82,7 @@ int volume__eq(lua_State* L) {
 
 int volume__index(lua_State* L) {
     volume_t* volume = luaL_checkudata(L, 1, LUA_PA_VOLUME);
-    int index = luaL_checkint(L, 2);
+    int index = (int) luaL_checkinteger(L, 2);
     luaL_argcheck(L, index >= 1 && index <= (PA_CHANNELS_MAX + 1), 2, "channel index out of bounds");
     lua_pushinteger(L, volume->inner.values[index - 1]);
     return 1;