[PATCH 2/2] python-cffi: use config_pairs API in ConfigIterator

[David Bremner <david@tethera.net>]

This returns all of the config keys with non-empty values, not just
those that happen to be stored in the database.
---
 bindings/python-cffi/notmuch2/_build.py   | 16 +++++-----
 bindings/python-cffi/notmuch2/_config.py  | 37 +++++++++++++++--------
 bindings/python-cffi/tests/test_config.py | 22 ++++++++------
 test/T055-path-config.sh                  |  1 -
 4 files changed, 44 insertions(+), 32 deletions(-)

diff --git a/bindings/python-cffi/notmuch2/_build.py b/bindings/python-cffi/notmuch2/_build.py
index a55b484f..349bb79d 100644
--- a/bindings/python-cffi/notmuch2/_build.py
+++ b/bindings/python-cffi/notmuch2/_build.py
@@ -97,7 +97,7 @@ ffibuilder.cdef(
     typedef struct _notmuch_string_map_iterator notmuch_message_properties_t;
     typedef struct _notmuch_directory notmuch_directory_t;
     typedef struct _notmuch_filenames notmuch_filenames_t;
-    typedef struct _notmuch_config_list notmuch_config_list_t;
+    typedef struct _notmuch_config_pairs notmuch_config_pairs_t;
     typedef struct _notmuch_indexopts notmuch_indexopts_t;
 
     const char *
@@ -325,18 +325,18 @@ ffibuilder.cdef(
     notmuch_database_set_config (notmuch_database_t *db, const char *key, const char *value);
     notmuch_status_t
     notmuch_database_get_config (notmuch_database_t *db, const char *key, char **value);
-    notmuch_status_t
-    notmuch_database_get_config_list (notmuch_database_t *db, const char *prefix, notmuch_config_list_t **out);
+    notmuch_config_pairs_t *
+    notmuch_config_get_pairs (notmuch_database_t *db, const char *prefix);
     notmuch_bool_t
-    notmuch_config_list_valid (notmuch_config_list_t *config_list);
+    notmuch_config_pairs_valid (notmuch_config_pairs_t *config_list);
     const char *
-    notmuch_config_list_key (notmuch_config_list_t *config_list);
+    notmuch_config_pairs_key (notmuch_config_pairs_t *config_list);
     const char *
-    notmuch_config_list_value (notmuch_config_list_t *config_list);
+    notmuch_config_pairs_value (notmuch_config_pairs_t *config_list);
     void
-    notmuch_config_list_move_to_next (notmuch_config_list_t *config_list);
+    notmuch_config_pairs_move_to_next (notmuch_config_pairs_t *config_list);
     void
-    notmuch_config_list_destroy (notmuch_config_list_t *config_list);
+    notmuch_config_pairs_destroy (notmuch_config_pairs_t *config_list);
     """
 )
 
diff --git a/bindings/python-cffi/notmuch2/_config.py b/bindings/python-cffi/notmuch2/_config.py
index 29de6495..d73539c5 100644
--- a/bindings/python-cffi/notmuch2/_config.py
+++ b/bindings/python-cffi/notmuch2/_config.py
@@ -13,27 +13,39 @@ class ConfigIter(base.NotmuchIter):
     def __init__(self, parent, iter_p):
         super().__init__(
             parent, iter_p,
-            fn_destroy=capi.lib.notmuch_config_list_destroy,
-            fn_valid=capi.lib.notmuch_config_list_valid,
-            fn_get=capi.lib.notmuch_config_list_key,
-            fn_next=capi.lib.notmuch_config_list_move_to_next)
+            fn_destroy=capi.lib.notmuch_config_pairs_destroy,
+            fn_valid=capi.lib.notmuch_config_pairs_valid,
+            fn_get=capi.lib.notmuch_config_pairs_key,
+            fn_next=capi.lib.notmuch_config_pairs_move_to_next)
 
     def __next__(self):
-        item = super().__next__()
-        return base.BinString.from_cffi(item)
-
+        # skip pairs whose value is NULL
+        while capi.lib.notmuch_config_pairs_valid (super()._iter_p):
+            val_p = capi.lib.notmuch_config_pairs_value (super()._iter_p)
+            key_p = capi.lib.notmuch_config_pairs_key (super()._iter_p)
+            key = base.BinString.from_cffi(key_p)
+            capi.lib.notmuch_config_pairs_move_to_next (super()._iter_p)
+            if val_p != capi.ffi.NULL and base.BinString.from_cffi(val_p) != "":
+                return key
+        self._destroy()
+        raise StopIteration
 
 class ConfigMapping(base.NotmuchObject, collections.abc.MutableMapping):
-    """The config key/value pairs stored in the database.
+    """The config key/value pairs loaded from the database, config file,
+    and and/or defaults.
 
     The entries are exposed as a :class:`collections.abc.MutableMapping` object.
     Note that setting a value to an empty string is the same as deleting it.
 
+    Mutating (deleting or updating values) in the map persists only in
+    the database, which can be shadowed by config files.
+
     :param parent: the parent object
     :param ptr_name: the name of the attribute on the parent which will
        return the memory pointer.  This allows this object to
        access the pointer via the parent's descriptor and thus
        trigger :class:`MemoryPointer`'s memory safety.
+
     """
 
     def __init__(self, parent, ptr_name):
@@ -77,11 +89,10 @@ class ConfigMapping(base.NotmuchObject, collections.abc.MutableMapping):
 
         :raises NullPointerError: If the iterator can not be created.
         """
-        configlist_pp = capi.ffi.new('notmuch_config_list_t**')
-        ret = capi.lib.notmuch_database_get_config_list(self._ptr(), b'', configlist_pp)
-        if ret != capi.lib.NOTMUCH_STATUS_SUCCESS:
-            raise errors.NotmuchError(ret)
-        return ConfigIter(self._parent, configlist_pp[0])
+        config_pairs_p = capi.lib.notmuch_config_get_pairs(self._ptr(), b'')
+        if config_pairs_p == capi.ffi.NULL:
+            raise KeyError
+        return ConfigIter(self._parent, config_pairs_p)
 
     def __len__(self):
         return sum(1 for t in self)
diff --git a/bindings/python-cffi/tests/test_config.py b/bindings/python-cffi/tests/test_config.py
index 67b0dea4..c62aeb98 100644
--- a/bindings/python-cffi/tests/test_config.py
+++ b/bindings/python-cffi/tests/test_config.py
@@ -34,20 +34,22 @@ class TestIter:
             print(repr(val))
 
     def test_iter(self, db):
-        assert list(db.config) == []
-        db.config['spam'] = 'ham'
-        db.config['eggs'] = 'bacon'
-        assert set(db.config) == {'spam', 'eggs'}
-        assert set(db.config.keys()) == {'spam', 'eggs'}
-        assert set(db.config.values()) == {'ham', 'bacon'}
-        assert set(db.config.items()) == {('spam', 'ham'), ('eggs', 'bacon')}
+        import re
+        prefix = re.compile(r"^TEST[.]")
+        assert [ x for x in list(db.config) if prefix.match(x) ] == []
+        db.config['TEST.spam'] = 'TEST.ham'
+        db.config['TEST.eggs'] = 'TEST.bacon'
+        assert { x for x in set(db.config) if prefix.match(x) } == {'TEST.spam', 'TEST.eggs'}
+        assert { x for x in set(db.config.keys()) if prefix.match (x) } == {'TEST.spam', 'TEST.eggs'}
+        assert { x for x in set(db.config.values()) if prefix.match (x) } == {'TEST.ham', 'TEST.bacon'}
+        assert { (x, y) for (x,y) in set(db.config.items()) if prefix.match(x) } == {('TEST.spam', 'TEST.ham'), ('TEST.eggs', 'TEST.bacon')}
 
     def test_len(self, db):
-        assert len(db.config) == 0
+        defaults = len(db.config)
         db.config['spam'] = 'ham'
-        assert len(db.config) == 1
+        assert len(db.config) == defaults + 1
         db.config['eggs'] = 'bacon'
-        assert len(db.config) == 2
+        assert len(db.config) == defaults + 2
 
     def test_del(self, db):
         db.config['spam'] = 'ham'
diff --git a/test/T055-path-config.sh b/test/T055-path-config.sh
index 71823039..4897c814 100755
--- a/test/T055-path-config.sh
+++ b/test/T055-path-config.sh
@@ -294,7 +294,6 @@ EOF
    test_expect_equal_file EXPECTED OUTPUT
 
    test_begin_subtest "Config list from python ($config)"
-   test_subtest_known_broken
    test_python <<EOF > OUTPUT
 from notmuch2 import Database
 db=Database(config=Database.CONFIG.SEARCH)
-- 
2.34.1