ade: Provide conventional handling for the -- pseudo-option

The common convention of passing "--" as a separator between
arguments for this command and arguments for the wrapped command
did not work, because it would also pass the "--" through. For
instance, "ade configure --native -- --device=foo" should pass
"--device=foo" to the configure script instead of interpreting it
as ade's own --device option.

Signed-off-by: Simon McVittie <smcv@collabora.com>
Reviewed-by: André Magalhães <andre.magalhaes@collabora.co.uk>
Differential Revision: https://phabricator.apertis.org/D6796

tools/ade

@@ -1647,6 +1647,13 @@ if __name__ == '__main__':
     obj = Ade()
     args, extra = root_parser.parse_known_args(namespace=obj)
     if hasattr(obj, 'args'):
+        if obj.args and obj.args[0] == '--':
+            # REMAINING arguments include the "--" if the user supplied one.
+            # Remove it. If there is more than one instance "--", this still
+            # does the right thing, by passing n-1 instances to the next
+            # layer of wrapped tools.
+            obj.args = obj.args[1:]
+
         obj.args += extra
     elif extra:
         # Re-parse the command line without unknown arguments allowed,