properties: fix mozila properties encoding space

This ancient workaround for Pootle is no longer needed.

Fixes #3232

tests/translate/convert/test_po2prop.py

@@ -194,7 +194,7 @@ def test_mozilla_all_whitespace(self):
         proptemplate = """accesskey-accept=
 accesskey-help=H
 """
-        propexpected = """accesskey-accept=
+        propexpected = r"""accesskey-accept=\u0020
 accesskey-help=م
 """
         propfile = self.merge2prop(proptemplate, posource, personality="mozilla")

tests/translate/misc/test_quote.py

@@ -127,10 +127,10 @@ def test_escapespace():
 
     @staticmethod
     def test_mozillaescapemarginspaces():
-        assert quote.mozillaescapemarginspaces(" ") == ""
+        assert quote.mozillaescapemarginspaces(" ") == r"\u0020"
         assert quote.mozillaescapemarginspaces("A") == "A"
-        assert quote.mozillaescapemarginspaces(" abc ") == "\\u0020abc\\u0020"
-        assert quote.mozillaescapemarginspaces("  abc ") == "\\u0020 abc\\u0020"
+        assert quote.mozillaescapemarginspaces(" abc ") == r"\u0020abc\u0020"
+        assert quote.mozillaescapemarginspaces("  abc ") == r"\u0020 abc\u0020"
 
     @staticmethod
     def test_mozilla_control_escapes():

tests/translate/storage/test_properties.py

@@ -356,6 +356,19 @@ def test_newlines_startend(self):
         propregen = self.propregen(propsource)
         assert propsource + "\n" == propregen
 
+    def test_space(self):
+        r"""Check that we preserve \n that appear at start and end of properties."""
+        propsource = r"""space=\u0020
+endspace=,\u0020
+"""
+        store = self.propparse(propsource, personality="mozilla")
+        assert len(store.units) == 2
+        assert store.units[0].source == " "
+        assert store.units[1].source == ", "
+        store.units[0].source = " "
+        store.units[1].source = ", "
+        assert bytes(store).decode("utf-8") == propsource
+
     def test_whitespace_handling(self):
         """Check that we remove extra whitespace around property."""
         whitespaces = (

translate/misc/quote.py

@@ -404,13 +404,6 @@ def mozillaescapemarginspaces(source: str) -> str:
     """Escape leading and trailing spaces for Mozilla .properties files."""
     if not source:
         return ""
-
-    if len(source) == 1 and source.isspace():
-        # FIXME: This is hack for people using white-space to mark empty
-        # Mozilla strings translated, drop this once we have better way to
-        # handle this in Pootle.
-        return ""
-
     if len(source) == 1:
         return escapespace(source)
     return escapespace(source[0]) + source[1:-1] + escapespace(source[-1])