In modern aircraft, damage of hydraulic tubes can be repaired by Permaswage/Harrison provided by maintenance manuel. However, What is Permaswage / Harrison? It's a name of company?
A quick google for "Permaswage/Harrison" reveals that
Permaswage is the technology leader in the fluid fitting industry providing proprietary and standard components, tooling, and training to all major aerospace companies globally.
"Harrison" seems to refer to a variety of internal swage fittings that are separable ridge tube end fittings commonly used in aerospace fluid transfer applications:
They are also referred as “Harrison”, “Stanley Aviation” or “Sierracin” fittings, due to the history of the product.
From this, I would deduce that one can use these products to effect a repair to hydraulic lines with these methods/products because:
Internal swaging is a mechanical method for the attachment of fittings to tubing. This is accomplished by forming tubing outward into grooves within the fitting.
--From the "Harrison" link