backport bugfixes from 0.3.6

CHANGELOG.md

@@ -4,6 +4,14 @@
 
 + Added `ValueProperty`, abstract superclass for `ConfigProperty`.
 
+## 0.3.6
+
+- Fixed `ConfigValue` behavior with multiple sources. It used to iterate through all the sources, possibly overwriting; now, iteration stops at first non-missing value.
+
+## 0.3.5
+
+- Fixed cb32 handling. Now leading zeros in SIQ's are stripped, and `.from_cb32()` was implemented.
+
 ## 0.3.4
 
 - Bug fixes in `.flask_restx` regarding error handling

src/suou/classtools.py

@@ -170,10 +170,11 @@ class ValueProperty(Generic[_T]):
                         if srckey != 'default':
                             logger.info(f'value {self._name} found in {srckey} source')
                         break
-            if self._required and (not v or v is MISSING):
-                raise self._not_found(f'required config {self._srcs['default']} not set!')
-            if v is MISSING:
-                v = self._default
+            if not _not_missing(v):
+                if self._required:
+                    raise self._not_found(f'required config {self._srcs['default']} not set!')
+                else:
+                    v = self._default
             if callable(self._cast):
                 v = self._cast(v) if v is not None else self._cast()
             self._val = v