Fix system locale detection on MS Windows.

Some system locales were not correctly identified on Microsoft Windows
causing Gramps to open in English even though a translation is available
for the locale.

gramps/gen/utils/win32locale.py

@@ -117,12 +117,21 @@ def _check_mswin_locale(loc):
 
 
 def _check_mswin_locale_reverse(loc):
-    for newloc, msloc in _LOCALE_NAMES.items():
-        if msloc and newloc == msloc[0]:
-            return (newloc, msloc[1])
+    (lang, country) = loc.split("_")
     # US English is the outlier, all other English locales want real English:
-    if loc.startswith("English") and loc != "English_United States":
+    if lang == "English" and country != "United States":
         return ("en_GB", "1252")
+
+    for newloc, msloc in _LOCALE_NAMES.items():
+        if not msloc[0] is None and loc == msloc[0]:
+            return (newloc, msloc[1])
+
+    # Didn't get a full language-country match, find the first locale
+    # with the same language:
+    for newloc, msloc in _LOCALE_NAMES.items():
+        if loc == msloc[2] or lang == msloc[2]:
+            return (newloc, msloc[1])
+
     return (None, None)
 
 
@@ -137,17 +146,17 @@ def _set_lang(glocale):
             LOG.debug("%%LANG%% value %s not usable", os.environ["LANG"])
     if not glocale.lang:
         locale.setlocale(locale.LC_ALL, "")
-        locale_tuple = locale.getlocale()
-        lang = locale_tuple[0]
-        loc = _check_mswin_locale_reverse(lang)
-        if loc[0]:
-            glocale.lang = loc[0]
-            glocale.encoding = loc[1]
-        else:
-            (lang, loc) = _check_mswin_locale(locale.getlocale()[0])
-            if lang:
+        (pylang, pyenc) = locale.getlocale()
+        # Sometimes getlocale returns a Microsoft locale code
+        (lang, enc) = _check_mswin_locale_reverse(pylang)
+        if not lang is None:
+            glocale.lang = lang
+            glocale.encoding = enc
+        else:  # and sometimes it returns a POSIX locale
+            (lang, enc) = _check_mswin_locale(pylang)
+            if not lang is None:
                 glocale.lang = lang
-                glocale.encoding = loc[1]
+                glocale.encoding = enc
             else:
                 LOG.debug("No usable locale found in environment")