Merge branch 'better-error-handling'

Closes https://github.com/awesomeWM/awesome/pull/311

event.c

@@ -116,11 +116,11 @@ event_handle_mousegrabber(int x, int y, uint16_t mask)
     if(globalconf.mousegrabber != LUA_REFNIL)
     {
         lua_State *L = globalconf_get_lua_State();
-        lua_rawgeti(L, LUA_REGISTRYINDEX, globalconf.mousegrabber);
         mousegrabber_handleevent(L, x, y, mask);
-        if(lua_pcall(L, 1, 1, 0))
+        lua_rawgeti(L, LUA_REGISTRYINDEX, globalconf.mousegrabber);
+        if(!luaA_dofunction(L, 1, 1))
         {
-            warn("error running function: %s", lua_tostring(L, -1));
+            warn("Stopping mousegrabber.");
             luaA_mousegrabber_stop(L);
         }
         else if(!lua_isboolean(L, -1) || !lua_toboolean(L, -1))
@@ -599,16 +599,17 @@ event_handle_key(xcb_key_press_event_t *ev)
 
     if(globalconf.keygrabber != LUA_REFNIL)
     {
-        lua_rawgeti(L, LUA_REGISTRYINDEX, globalconf.keygrabber);
         if(keygrabber_handlekpress(L, ev))
         {
-            if(lua_pcall(L, 3, 1, 0))
+            lua_rawgeti(L, LUA_REGISTRYINDEX, globalconf.keygrabber);
+
+            if(!luaA_dofunction(L, 3, 1))
             {
-                warn("error running function: %s", lua_tostring(L, -1));
+                warn("Stopping keygrabber.");
                 luaA_keygrabber_stop(L);
             }
+            lua_pop(L, 1);
         }
-        lua_pop(L, 1);  /* pop returned value or function if not called */
     }
     else
     {

lib/awful/keygrabber.lua

@@ -20,9 +20,9 @@ local keygrabbing = false
 
 
 local function grabber(mod, key, event)
-    for i, g in ipairs(grabbers) do
+    for i, keygrabber_function in ipairs(grabbers) do
         -- continue if the grabber explicitly returns false
-        if g(mod, key, event) ~= false then
+        if keygrabber_function(mod, key, event) ~= false then
             break
         end
     end

lib/awful/widget/tasklist.lua

@@ -161,8 +161,8 @@ function tasklist.new(screen, filter, buttons, style, update_function, base_widg
         -- Add a delayed callback for the first update.
         if not queued_update then
             timer.delayed_call(function()
+                queued_update = false
                 tasklist_update(screen, w, buttons, filter, data, style, uf)
-                queued_update = nil
             end)
             queued_update = true
         end

lib/beautiful/init.lua

@@ -103,7 +103,8 @@ function beautiful.init(config)
         if type(config) == 'string' then
             -- Expand the '~' $HOME shortcut
             config = config:gsub("^~/", homedir .. "/")
-            success, theme = pcall(function() return dofile(config) end)
+            success, theme = xpcall(function() return dofile(config) end,
+                                    debug.traceback)
         elseif type(config) == 'table' then
             success = true
             theme = config

lib/gears/timer.lua

@@ -37,12 +37,11 @@ function timer:start()
         return
     end
     self.data.source_id = glib.timeout_add(glib.PRIORITY_DEFAULT, self.data.timeout * 1000, function()
-        local success, message = pcall(function()
-            self:emit_signal("timeout")
-        end)
-        if not success then
-            print(message)
-        end
+        local success, message = xpcall(function()
+                self:emit_signal("timeout")
+            end, function(err)
+                print(debug.traceback("Error during executing timeout handler: "..tostring(err)))
+            end)
         return true
     end)
 end
@@ -107,10 +106,11 @@ end
 local delayed_calls = {}
 capi.awesome.connect_signal("refresh", function()
     for _, callback in ipairs(delayed_calls) do
-        local success, message = pcall(unpack(callback))
-        if not success then
-            print(message)
-        end
+        local success, message = xpcall(function()
+                callback[1](unpack(callback, 2))
+            end, function(err)
+                print(debug.traceback("Error during delayed call: "..tostring(err)))
+            end)
     end
     delayed_calls = {}
 end)

luaa.h

@@ -56,6 +56,9 @@ luaA_warn(lua_State *L, const char *fmt, ...)
     vfprintf(stderr, fmt, ap);
     va_end(ap);
     fprintf(stderr, "\n");
+
+    luaL_traceback(L, L, NULL, 2);
+    fprintf(stderr, "%s\n", lua_tostring(L, -1));
 }
 
 static inline int
@@ -63,6 +66,8 @@ luaA_typerror(lua_State *L, int narg, const char *tname)
 {
     const char *msg = lua_pushfstring(L, "%s expected, got %s",
                                       tname, luaL_typename(L, narg));
+    luaL_traceback(L, L, NULL, 2);
+    lua_concat(L, 2);
     return luaL_argerror(L, narg, msg);
 }
 

tests/_runner.lua

@@ -29,7 +29,9 @@ runner.run_steps = function(steps)
     local step_as_string = step..'/'..#steps..' (@'..step_count..')'
 
     -- Call the current step's function.
-    local success, result = pcall(steps[step], step_count)
+    local success, result = xpcall(function()
+        return steps[step](step_count)
+      end, debug.traceback)
 
     if not success then
       io.stderr:write('Error: running function for step '