Make gears.object:emit_signal fail proof (Fix #3667)

lib/gears/object.lua

@@ -14,6 +14,7 @@ local pairs = pairs
 local type = type
 local error = error
 local properties = require("gears.object.properties")
+local protected_call = require("gears.protected_call")
 
 local object = { properties = properties, mt = {} }
 
@@ -132,13 +133,13 @@ end
 function object:emit_signal(name, ...)
     local sig = find_signal(self, name)
     for func in pairs(sig.strong) do
-        func(self, ...)
+        protected_call(func, self, ...)
     end
     for func in pairs(sig.weak) do
-        func(self, ...)
+        protected_call(func, self, ...)
     end
     for _, func in ipairs(self._global_receivers) do
-        func(name, self, ...)
+        protected_call(func, name, self, ...)
     end
 end
 
@@ -158,7 +159,7 @@ function object._setup_class_signals(t, args)
             assert(name)
             for _, func in pairs(conns[name] or {}) do
                 if condition(...) then return end
-                func(...)
+                protected_call(func, ...)
             end
         end
     end

spec/gears/object_spec.lua

@@ -4,6 +4,7 @@
 ---------------------------------------------------------------------------
 
 local object = require("gears.object")
+local gdebug = require("gears.debug")
 
 describe("gears.object", function()
     local obj
@@ -185,6 +186,29 @@ describe("gears.object", function()
             object{enable_auto_signals=true, enable_properties=false}
         end)
     end)
+
+    it(
+        "signal callback with exception shouldn't break the emit_signal function",
+        function()
+            -- Stop the error reporting during tests
+            local orig_print_error = gdebug.print_error
+            gdebug.print_error = function() end
+
+            local cb = spy.new(function() end)
+            obj:connect_signal("error", function()
+                error "error"
+            end)
+            obj:connect_signal("error", function()
+                cb()
+            end)
+
+            obj:emit_signal "error"
+            assert.spy(cb).was_called()
+
+            -- Restore gdebug
+            gdebug.print_error = orig_print_error
+        end
+    )
 end)
 
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