Bug report

Bug description:

On Windows,urllib.request.url2pathname() mishandles an uncommon file URI variant encoding a UNC path. Specifically, a URI withfive leading slashes should be converted to a UNC path withtwo leading slashes, buturl2pathname() returns a path withthree leading slashes. Such URIs are created by software that simply prependsfile:/// to a Windows path. SeeRFC 8089 E.3.2, final example.

>>>fromurllib.requestimporturl2pathname>>>url2pathname('/////server/share')'\\\\\\server\\share'# expected: '\\\\server\\share'

CPython versions tested on:

CPython main branch

Operating systems tested on:

Windows

Linked PRs

• GH-127078:url2pathname(): handle extra slash before UNC drive in URL path #127132
• [3.13] GH-127078:url2pathname(): handle extra slash before UNC drive in URL path (GH-127132) #127135
• [3.12] GH-127078:url2pathname(): handle extra slash before UNC drive in URL path (GH-127132) #127136