[3.11] bpo-18319: gettext() can retrieve a message even if a plural form exists (GH-19869) (GH-107107)

(cherry picked from commit 5463252)

Co-authored-by: Gilles Bassière <[email protected]>

Author: miss-islington

Lib/gettext.py

@@ -422,10 +422,12 @@ def gettext(self, message):
         missing = object()
         tmsg = self._catalog.get(message, missing)
         if tmsg is missing:
-            if self._fallback:
-                return self._fallback.gettext(message)
-            return message
-        return tmsg
+            tmsg = self._catalog.get((message, self.plural(1)), missing)
+        if tmsg is not missing:
+            return tmsg
+        if self._fallback:
+            return self._fallback.gettext(message)
+        return message
 
     def ngettext(self, msgid1, msgid2, n):
         try:

Lib/test/test_gettext.py

@@ -320,6 +320,8 @@ def test_plural_forms1(self):
         eq(x, 'Hay %s fichero')
         x = gettext.ngettext('There is %s file', 'There are %s files', 2)
         eq(x, 'Hay %s ficheros')
+        x = gettext.gettext('There is %s file')
+        eq(x, 'Hay %s fichero')
 
     def test_plural_context_forms1(self):
         eq = self.assertEqual
@@ -340,6 +342,8 @@ def test_plural_forms2(self):
         eq(x, 'Hay %s fichero')
         x = t.ngettext('There is %s file', 'There are %s files', 2)
         eq(x, 'Hay %s ficheros')
+        x = t.gettext('There is %s file')
+        eq(x, 'Hay %s fichero')
 
     def test_plural_context_forms2(self):
         eq = self.assertEqual

Misc/NEWS.d/next/Library/2020-05-03-00-33-15.bpo-18319.faPTlx.rst

@@ -0,0 +1,2 @@
+Ensure ``gettext(msg)`` retrieve translations even if a plural form exists. In
+other words: ``gettext(msg) == ngettext(msg, '', 1)``.