Allow catalog updates without new fuzzy flags

babel/messages/catalog.py

@@ -906,6 +906,7 @@ def update(
         update_header_comment: bool = False,
         keep_user_comments: bool = True,
         update_creation_date: bool = True,
+        no_fuzzy_flags: bool = False,
     ) -> None:
         """Update the catalog based on the given template catalog.
 
@@ -961,6 +962,9 @@ def update(
         :param update_header_comment: whether to copy the header comment from the template
         :param keep_user_comments: whether to keep user comments from the old catalog
         :param update_creation_date: whether to copy the creation date from the template
+        :param no_fuzzy_flags: do not mark messages as fuzzy solely because their
+                              IDs were matched approximately. Existing fuzzy
+                              flags and flags caused by plural changes are kept.
         """
         messages = self._messages
         remaining = messages.copy()
@@ -984,7 +988,7 @@ def _merge(
             message = message.clone()
             fuzzy = False
             if oldkey != newkey:
-                fuzzy = True
+                fuzzy = not no_fuzzy_flags
                 fuzzy_matches.add(oldkey)
                 oldmsg = messages.get(oldkey)
                 assert oldmsg is not None

babel/messages/frontend.py

@@ -713,6 +713,8 @@ class UpdateCatalog(CommandMixin):
          'do not use fuzzy matching'),
         ('update-header-comment', None,
          'update target header comment'),
+        ('no-fuzzy-flags', None,
+         'do not mark fuzzy matches as fuzzy'),
         ('previous', None,
          'keep previous msgids of translated messages'),
         ('check=', None,
@@ -730,6 +732,7 @@ class UpdateCatalog(CommandMixin):
         'no-fuzzy-matching',
         'previous',
         'update-header-comment',
+        'no-fuzzy-flags',
         'check',
         'ignore-pot-creation-date',
     ]
@@ -747,6 +750,7 @@ def initialize_options(self):
         self.init_missing = False
         self.no_fuzzy_matching = False
         self.update_header_comment = False
+        self.no_fuzzy_flags = False
         self.previous = False
         self.check = False
         self.ignore_pot_creation_date = False
@@ -830,6 +834,7 @@ def run(self):
                 template,
                 no_fuzzy_matching=self.no_fuzzy_matching,
                 update_header_comment=self.update_header_comment,
+                no_fuzzy_flags=self.no_fuzzy_flags,
                 update_creation_date=not self.ignore_pot_creation_date,
             )
 

docs/cmdline.rst

@@ -236,6 +236,7 @@ a PO template file::
                             do not use fuzzy matching
       --update-header-comment
                             update target header comment
+      --no-fuzzy-flags       do not mark fuzzy matches as fuzzy
       --previous            keep previous msgids of translated messages
 
 
@@ -248,6 +249,16 @@ If neither the ``output_file`` nor the ``locale`` option is set, this command
 looks for all catalog files in the base directory that match the given domain,
 and updates each of them.
 
+When correcting source text without changing its meaning, such as fixing a
+spelling error, ``--no-fuzzy-flags`` reuses approximately matched translations
+without adding a ``fuzzy`` flag just because the message ID changed. Use this
+option only when the existing translations are known to remain valid. Existing
+``fuzzy`` flags are preserved, and changes to the singular/plural structure or
+the number of plural translations still mark a message as fuzzy.
+
+This differs from ``--no-fuzzy-matching``, which disables approximate matching
+and therefore does not reuse translations for changed message IDs.
+
 concat
 ======
 

tests/messages/frontend/test_frontend.py

@@ -25,7 +25,7 @@
     ExtractMessages,
     UpdateCatalog,
 )
-from babel.messages.pofile import write_po
+from babel.messages.pofile import read_po, write_po
 from tests.messages.consts import project_dir
 from tests.messages.utils import CUSTOM_EXTRACTOR_COOKIE
 
@@ -239,6 +239,35 @@ def test_update_catalog_boolean_args():
     assert cmdinst.previous is False  # Mutually exclusive with no_fuzzy_matching
 
 
+@pytest.mark.parametrize('no_fuzzy_flags', [False, True])
+def test_update_catalog_no_fuzzy_flags(tmp_path, no_fuzzy_flags):
+    template = Catalog()
+    template.add('Save changes')
+    template.add('Existing fuzzy')
+    cat = Catalog(locale='de', fuzzy=False)
+    cat.add('Save chnages', 'Speichern')
+    cat.add('Existing fuzzy', 'Ungeprüft', flags=['fuzzy'])
+    pot = tmp_path / 'messages.pot'
+    po = tmp_path / 'de.po'
+    for path, value in [(pot, template), (po, cat)]:
+        with path.open('wb') as file:
+            write_po(file, value)
+
+    cmd = configure_cli_command([
+        'update', '-i', str(pot), '-o', str(po), '-l', 'de', '--previous',
+        *(['--no-fuzzy-flags'] if no_fuzzy_flags else []),
+    ])
+    cmd.run()
+
+    with po.open('rb') as file:
+        result = read_po(file)
+    assert result['Save changes'].string == 'Speichern'
+    assert result['Save changes'].fuzzy is (not no_fuzzy_flags)
+    assert result['Existing fuzzy'].fuzzy
+    assert not result.obsolete
+    assert '#| msgid "Save chnages"' in po.read_text(encoding='utf-8')
+
+
 def test_compile_catalog_dir(tmp_path):
     """
     Test that `compile` can compile all locales in a directory.

tests/messages/test_catalog.py

@@ -15,6 +15,8 @@
 import pickle
 from io import StringIO
 
+import pytest
+
 from babel.dates import UTC, format_datetime
 from babel.messages import catalog, pofile
 from babel.util import FixedOffsetTimezone
@@ -158,6 +160,56 @@ def test_catalog_update_fuzzy_matching_with_case_change():
     assert cat['foo'].fuzzy is True
 
 
+@pytest.mark.parametrize('no_fuzzy_flags', [False, True])
+@pytest.mark.parametrize('already_fuzzy', [False, True])
+@pytest.mark.parametrize('context', [None, 'button'])
+@pytest.mark.parametrize('plural', [False, True])
+def test_catalog_update_no_fuzzy_flags(no_fuzzy_flags, already_fuzzy, context, plural):
+    cat = catalog.Catalog(locale='de')
+    old_id = ('Save chnages', 'Save all chnages') if plural else 'Save chnages'
+    new_id = ('Save changes', 'Save all changes') if plural else 'Save changes'
+    translation = ('Speichern', 'Alle speichern') if plural else 'Speichern'
+    flags = {'fuzzy'} if already_fuzzy else set()
+    cat.add(old_id, translation, context=context, flags=flags, user_comments=['Keep this'])
+    tmpl = catalog.Catalog()
+    tmpl.add(new_id, context=context, locations=[('main.py', 42)])
+
+    cat.update(tmpl, no_fuzzy_flags=no_fuzzy_flags)
+
+    message = cat.get(new_id, context=context)
+    assert message.string == translation
+    assert message.fuzzy is (already_fuzzy or not no_fuzzy_flags)
+    assert message.previous_id == (list(old_id) if plural else [old_id])
+    assert message.user_comments == ['Keep this']
+    assert message.locations == [('main.py', 42)]
+    assert not cat.obsolete
+    assert not tmpl.get(new_id, context=context).fuzzy
+
+
+@pytest.mark.parametrize(('old_id', 'translation', 'new_id'), [
+    ('item', 'Ding', ('item', 'items')),
+    (('item', 'items'), ('Ding', 'Dinge'), 'item'),
+    (('item', 'items'), ('Ding',), ('item', 'items')),
+])
+def test_catalog_update_no_fuzzy_flags_preserves_plural_checks(old_id, translation, new_id):
+    cat = catalog.Catalog(locale='de')
+    cat.add(old_id, translation)
+    tmpl = catalog.Catalog()
+    tmpl.add(new_id)
+    cat.update(tmpl, no_fuzzy_flags=True)
+    assert cat[new_id].fuzzy
+
+
+def test_catalog_update_no_fuzzy_flags_with_no_matching():
+    cat = catalog.Catalog(locale='de')
+    cat.add('Save chnages', 'Speichern')
+    tmpl = catalog.Catalog()
+    tmpl.add('Save changes')
+    cat.update(tmpl, no_fuzzy_matching=True, no_fuzzy_flags=True)
+    assert not cat['Save changes'].string
+    assert 'Save chnages' in cat.obsolete
+
+
 def test_catalog_update_fuzzy_matching_with_char_change():
     cat = catalog.Catalog()
     cat.add('fo', 'Voh')