drawable/drawin: Pass both lua_State and stack index around

A stack index without the corresponding lua_State pointer is useless, because it
could reference another coroutine than the main thread and thus just assuming
globalconf.L is wrong. Fix this by also passing around the corresponding
lua_State pointer.

This improves the result for the following test:

  coroutine.resume(coroutine.create(function()
      drawin({}).visible = true
  end))

Signed-off-by: Uli Schlachter <psychon@znc.in>

objects/client.c

@@ -797,7 +797,7 @@ client_resize_do(client_t *c, area_t geometry, bool force_notice, bool honor_hin
         area.y += geometry.y;
         if (hide_titlebars)
             area.width = area.height = 0;
-        drawable_set_geometry(drawable, -1, area);
+        drawable_set_geometry(globalconf.L, -1, area);
 
         /* Pop the client and the drawable */
         lua_pop(globalconf.L, 2);

objects/drawable.c

@@ -61,8 +61,9 @@ drawable_wipe(drawable_t *d)
 }
 
 void
-drawable_set_geometry(drawable_t *d, int didx, area_t geom)
+drawable_set_geometry(lua_State *L, int didx, area_t geom)
 {
+    drawable_t *d = luaA_checkudata(L, didx, &drawable_class);
     area_t old = d->geometry;
     d->geometry = geom;
 
@@ -77,17 +78,17 @@ drawable_set_geometry(drawable_t *d, int didx, area_t geom)
         d->surface = cairo_xcb_surface_create(globalconf.connection,
                                               d->pixmap, globalconf.visual,
                                               geom.width, geom.height);
-        luaA_object_emit_signal(globalconf.L, didx, "property::surface", 0);
+        luaA_object_emit_signal(L, didx, "property::surface", 0);
     }
 
     if (old.x != geom.x)
-        luaA_object_emit_signal(globalconf.L, didx, "property::x", 0);
+        luaA_object_emit_signal(L, didx, "property::x", 0);
     if (old.y != geom.y)
-        luaA_object_emit_signal(globalconf.L, didx, "property::y", 0);
+        luaA_object_emit_signal(L, didx, "property::y", 0);
     if (old.width != geom.width)
-        luaA_object_emit_signal(globalconf.L, didx, "property::width", 0);
+        luaA_object_emit_signal(L, didx, "property::width", 0);
     if (old.height != geom.height)
-        luaA_object_emit_signal(globalconf.L, didx, "property::height", 0);
+        luaA_object_emit_signal(L, didx, "property::height", 0);
 }
 
 /** Get a drawable's surface

objects/drawable.h

@@ -48,7 +48,7 @@ struct drawable_t
 typedef struct drawable_t drawable_t;
 
 drawable_t *drawable_allocator(lua_State *, drawable_refresh_callback *, void *);
-void drawable_set_geometry(drawable_t *, int, area_t);
+void drawable_set_geometry(lua_State *, int, area_t);
 void drawable_class_setup(lua_State *);
 
 #endif

objects/drawin.c

@@ -72,11 +72,12 @@ drawin_wipe(drawin_t *w)
 }
 
 static void
-drawin_update_drawing(drawin_t *w, int widx)
+drawin_update_drawing(lua_State *L, int widx)
 {
-    luaA_object_push_item(globalconf.L, widx, w->drawable);
-    drawable_set_geometry(w->drawable, -1, w->geometry);
-    lua_pop(globalconf.L, 1);
+    drawin_t *w = luaA_checkudata(L, widx, &drawin_class);
+    luaA_object_push_item(L, widx, w->drawable);
+    drawable_set_geometry(L, -1, w->geometry);
+    lua_pop(L, 1);
 }
 
 /** Refresh the window content by copying its pixmap data to its window.
@@ -124,7 +125,7 @@ drawin_moveresize(lua_State *L, int udx, area_t geometry)
         mask_vals |= XCB_CONFIG_WINDOW_HEIGHT;
     }
 
-    drawin_update_drawing(w, udx);
+    drawin_update_drawing(L, udx);
 
     /* Activate BMA */
     client_ignore_enterleave_events();
@@ -168,8 +169,9 @@ drawin_refresh_pixmap_partial(drawin_t *drawin,
 }
 
 static void
-drawin_map(drawin_t *drawin, int widx)
+drawin_map(lua_State *L, int widx)
 {
+    drawin_t *drawin = luaA_checkudata(L, widx, &drawin_class);
     /* Activate BMA */
     client_ignore_enterleave_events();
     /* Map the drawin */
@@ -182,7 +184,7 @@ drawin_map(drawin_t *drawin, int widx)
     drawin_array_append(&globalconf.drawins, drawin);
     /* Make sure it has a surface */
     if(drawin->drawable->surface == NULL)
-        drawin_update_drawing(drawin, widx);
+        drawin_update_drawing(L, widx);
 }
 
 static void
@@ -225,7 +227,7 @@ drawin_set_visible(lua_State *L, int udx, bool v)
 
         if(drawin->visible)
         {
-            drawin_map(drawin, udx);
+            drawin_map(L, udx);
             /* duplicate drawin */
             lua_pushvalue(L, udx);
             /* ref it */