Protect against nullicons

engine/findicons.py

@@ -152,7 +152,7 @@ if __name__ == "__main__":
     print(SEARCH_DIRECTORIES)
     print()
 
-    for exe in ("ZynAddSubFx", "patroneo", "jack_mixer", "carla", "ardour6", "synthv1"):
+    for exe in ("zynaddsubfx", "patroneo", "jack_mixer", "carla", "ardour6", "synthv1"):
         r = findIconPath(exe)
         if r:
             print (f"{exe} Best resolution: {r[0]}")

qtgui/mainwindow.py

@@ -261,7 +261,7 @@ class MainWindow(QtWidgets.QMainWindow):
         for entry in programs:
             exe = entry["argodejoExec"]
 
-            if "argodejoIconPath" in entry:
+            if "argodejoIconPath" in entry and entry["argodejoIconPath"]: #not null
                 icon = QtGui.QIcon(entry["argodejoIconPath"])
                 assert not icon.isNull()
             else: