Refactor FlagConverter to handle positional flags correctly

discord/ext/commands/flags.py

@@ -523,32 +523,10 @@ def parse_flags(cls, argument: str, *, ignore_extra: bool = True) -> Dict[str, L
         result: Dict[str, List[str]] = {}
         flags = cls.__commands_flags__
         aliases = cls.__commands_flag_aliases__
-        positional_flag = cls.__commands_flag_positional__
         last_position = 0
-        last_flag: Optional[Flag] = None
+        last_flag = cls.__commands_flag_positional__
 
         case_insensitive = cls.__commands_flag_case_insensitive__
-
-        if positional_flag is not None:
-            match = cls.__commands_flag_regex__.search(argument)
-            if match is not None:
-                begin, end = match.span(0)
-                value = argument[:begin].strip()
-                last_position = begin
-            else:
-                value = argument.strip()
-                last_position = len(argument)
-
-            if value:
-                name = positional_flag.name.casefold() if case_insensitive else positional_flag.name
-
-                try:
-                    values = result[name]
-                except KeyError:
-                    result[name] = [value]
-                else:
-                    values.append(value)
-
         for match in cls.__commands_flag_regex__.finditer(argument):
             begin, end = match.span(0)
             key = match.group('flag')
@@ -559,19 +537,25 @@ def parse_flags(cls, argument: str, *, ignore_extra: bool = True) -> Dict[str, L
                 key = aliases[key]
 
             flag = flags.get(key)
-            if last_position and last_flag is not None:
-                value = argument[last_position : begin - 1].lstrip()
-                if not value:
+
+            if last_flag is not None and (last_position or last_flag.positional):
+                if last_position:
+                    value = argument[last_position : begin - 1].lstrip()
+                else:
+                    value = argument[last_position : begin].strip()
+
+                if not value and last_position:
                     raise MissingFlagArgument(last_flag)
 
-                name = last_flag.name.casefold() if case_insensitive else last_flag.name
+                if last_position or value:
+                    name = last_flag.name.casefold() if case_insensitive else last_flag.name
 
-                try:
-                    values = result[name]
-                except KeyError:
-                    result[name] = [value]
-                else:
-                    values.append(value)
+                    try:
+                        values = result[name]
+                    except KeyError:
+                        result[name] = [value]
+                    else:
+                        values.append(value)
 
             last_position = end
             last_flag = flag