Fix - Fall back to English for untranslated tabcmd strings

dodo.py

@@ -226,6 +226,13 @@ def generate_mo():
     """
 
     def check_mo():
+        # The sample translations below include ja/ko/zh text, which a Windows console
+        # (cp1252) cannot print. Force UTF-8 so validation output is readable everywhere.
+        # doit replaces sys.stdout with its own writer while a task runs, so reconfigure
+        # the underlying console stream as well.
+        for stream in (sys.stdout, sys.__stdout__):
+            if hasattr(stream, "reconfigure"):
+                stream.reconfigure(encoding="utf-8", errors="replace")
         print("\n****** Validate all generated .mo files")
         for current_locale in LOCALES:
             LANG_DIR = os.path.join("tabcmd", "locales")

tabcmd/execution/localize.py

@@ -79,6 +79,12 @@ def define_locale_dir(logger):
 def _load_language(current_locale, domain, logger):
     locale_dir = define_locale_dir(logger)
     language: gettext.NullTranslations = gettext.translation(domain, locale_dir, languages=[current_locale])
+    if current_locale != "en":
+        # Messages not yet translated fall back to English instead of showing the raw key.
+        try:
+            language.add_fallback(gettext.translation(domain, locale_dir, languages=["en"]))
+        except Exception as e:
+            logger.debug("Could not load English fallback catalog: {}".format(e))
     language.install()  # I believe this is the expensive call
     _ = language.gettext
     return _

tests/test_localize.py

@@ -0,0 +1,13 @@
+import logging
+import unittest
+
+from tabcmd.execution import localize
+
+
+class LocalizeFallbackTests(unittest.TestCase):
+    def test_untranslated_key_falls_back_to_english(self):
+        key = "session.errors.password_file_not_found"
+        translate = localize._load_language("de", "tabcmd", logging.getLogger("test"))
+        text = translate(key)
+        assert text != key, text
+        assert "{0}" in text, text