Fix TimedeltaConverter allowing negative values by default (#6354)

Co-authored-by: zephyrkul <[email protected]>

redbot/core/commands/converter.py

@@ -334,6 +334,7 @@ class TimedeltaConverter(dpy_commands.Converter):
             If provided, any parsed value higher than this will raise an exception
         minimum : Optional[datetime.timedelta]
             If provided, any parsed value lower than this will raise an exception
+            Defaults to 0 seconds, pass None explicitly to allow negative values
         allowed_units : Optional[List[str]]
             If provided, you can constrain a user to expressing the amount of time
             in specific units. The units you can choose to provide are the same as the
@@ -344,7 +345,14 @@ class TimedeltaConverter(dpy_commands.Converter):
             apply.
         """
 
-        def __init__(self, *, minimum=None, maximum=None, allowed_units=None, default_unit=None):
+        def __init__(
+            self,
+            *,
+            minimum=timedelta(seconds=0),
+            maximum=None,
+            allowed_units=None,
+            default_unit=None,
+        ):
             self.allowed_units = allowed_units
             self.default_unit = default_unit
             self.minimum = minimum
@@ -372,7 +380,7 @@ def get_timedelta_converter(
         *,
         default_unit: Optional[str] = None,
         maximum: Optional[timedelta] = None,
-        minimum: Optional[timedelta] = None,
+        minimum: Optional[timedelta] = timedelta(seconds=0),
         allowed_units: Optional[List[str]] = None,
     ) -> Type[timedelta]:
         ...
@@ -383,7 +391,7 @@ def get_timedelta_converter(
         *,
         default_unit: Optional[str] = None,
         maximum: Optional[timedelta] = None,
-        minimum: Optional[timedelta] = None,
+        minimum: Optional[timedelta] = timedelta(seconds=0),
         allowed_units: Optional[List[str]] = None,
     ) -> Type[timedelta]:
         """
@@ -398,6 +406,7 @@ def get_timedelta_converter(
             If provided, any parsed value higher than this will raise an exception
         minimum : Optional[datetime.timedelta]
             If provided, any parsed value lower than this will raise an exception
+            Defaults to 0 seconds, pass None explicitly to allow negative values
         allowed_units : Optional[List[str]]
             If provided, you can constrain a user to expressing the amount of time
             in specific units. The units you can choose to provide are the same as the