tree 3a4b93a3fb2f37601a5cf46c8265f83e3b0f3bb5
parent 97bb4ef64c29fed61e544a0fdeda96218358463c
author Vaclav Brozek <vabr@chromium.org> 1620276026 +0000
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> 1620276026 +0000

Reland Canonicalise file:///./s: as file:///S: on Win

The original CL
https://chromium-review.googlesource.com/c/chromium/src/+/2860002
was reverted, because of a missed update in one test
expectation, which only showed on Win 7.

In the meantime, a sync from WPT resolved that failing
expectation
(https://chromium-review.googlesource.com/c/chromium/src/+/2871329)
so this CL also undoes the Win7 disabling of the
test
(https://chromium-review.googlesource.com/c/chromium/src/+/2874645).

Original CL description:

============
Canonicalise file:///./s: as file:///S: on Win

Chrome on Windows converts drive letters to upper case.
Currently it only recognises drive letters appearing
at the start of the path, optionally after a block of
slashes.

This leads to an inconsistency, where canonicalized URLs
are themselves not canonical. Example:
1. file:///./s: canonicalizes as file:///s:, because the
   initial "s:" is not recognised as a drive letter (there
   is "." in the path prefix preceding it).
2. However, file:///s: itself canonicalizes as file:///S:,
   because now the "s:" is at the beginning and thus
   recognised as a drive letter and converted to upper case.

That is bad, because canonicalzed URLs must be canonical,
following their very definition.

The associated bug https://crbug.com/1083031 discusses
various approaches to fix this, and the consensus among
domenic@, rsleevi@ and vabr@ was that the least bad solution
to ensure that canonicalizer URLs are canonical is to
treat each drive letter specification in the path as such
as long as the path segment preceding it has the canonical
form "/". This fixes the above problem with the non-canonical
results of canonicalization.

The fix comes with a cost of increasing the number of failing
web conformance tests for Chrome on Windows. However, it does
not really create a new problem:

First, already today, Chrome on Win canonicalizes
file://////s: as file:///S:, while outside of Win the result
is file:///s:.

Second, already today, Chrome on Win canonicalizes
file:///s: as file:///S:. This is, in fact, _the_ problem and
has been raised in https://github.com/whatwg/url/issues/515.
============

Bug: 1083031
Bug: 1205779
Change-Id: I40abdbf0e260fc4d9f1c908450b4eb2541b5b10a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2874649
Auto-Submit: Vaclav Brozek <vabr@chromium.org>
Commit-Queue: Mike West <mkwst@chromium.org>
Reviewed-by: Domenic Denicola <domenic@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#879692}