fix: path was url decoded but it should not for browser - #176029

…189835)

When the framework reports new route information via the
`routeInformationUpdated`
navigation message, the web engine rebuilds the URL and runs
`Uri.decodeComponent`
over the whole string before handing it to the browser history
(introduced in
flutter-team-archive/engine#40250). This strips one level of percent-encoding from
the address
bar on every report:

| Framework reports | Address bar before | Address bar after this PR |
|---|---|---|
| `/item/foo%2Fbar` | `/item/foo/bar` — refresh/share resolves to a
different route | `/item/foo%2Fbar` |
| `?q=x%26y` | `?q=x&y` — value splits into two query parameters |
`?q=x%26y` |
| `?color=%23ffffff` | `?color=#ffffff` — rest of the URL becomes a
fragment | `?color=%23ffffff` |

Because routers decode path parameters exactly once, this also made
`GoRouterState.pathParameters` differ between in-app navigation and a
subsequent
browser refresh of the same URL: each round trip through the engine
silently
dropped one encoding level.

## Fix

`handleNavigationMessage` keeps the scheme/authority stripping, but now
reassembles
the URL from the raw (still encoded) `path`, `query`, and `fragment`
components
instead of decoding the result. The browser's address bar now reflects
exactly what
the framework reported.

This supersedes flutter#176029, which was closed for inactivity (missing
tests). Unlike
that attempt, this PR also avoids reconstructing the query via
`Uri(queryParameters:)`, which re-encoded values differently than
reported
(e.g. `%20` in a query value came back as `+`), and it adds a regression
test.

## Tests

Adds a regression test to `lib/web_ui/test/engine/routing_test.dart`
asserting
that `%20`, `%2F`, and `%26` in path, query, and fragment survive the
round trip
into browser history unchanged. The existing `routeInformationUpdated
can handle
uri` test (scheme/authority stripping) is unaffected and still passes.

Fixes flutter#180373
Fixes flutter#171757
Fixes flutter#147857
Fixes flutter#155992

cc @mdebbar (you triaged flutter#176029 and invited a re-open — this picks that
up with tests)

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [AI contribution guidelines] and understand my
responsibilities, or I am not using AI tools.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

If this change needs to override an active code freeze, provide a
comment explaining why. The code freeze workflow can be overridden by
code reviewers. See pinned issues for any active code freezes with
guidance.

**Note**: The Flutter team is currently trialing the use of [Gemini Code
Assist for
GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code).
Comments from the `gemini-code-assist` bot should not be taken as
authoritative feedback from the Flutter team. If you find its comments
useful you can update your code accordingly, but if you are unsure or
disagree with the feedback, please feel free to wait for a Flutter team
member's review for guidance on which automated comments should be
addressed.

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[AI contribution guidelines]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

---------

Co-authored-by: Mouad Debbar <[email protected]>
Co-authored-by: zhongliugo <[email protected]>

…189835)

When the framework reports new route information via the
`routeInformationUpdated`
navigation message, the web engine rebuilds the URL and runs
`Uri.decodeComponent`
over the whole string before handing it to the browser history
(introduced in
flutter-team-archive/engine#40250). This strips one level of percent-encoding from
the address
bar on every report:

| Framework reports | Address bar before | Address bar after this PR |
|---|---|---|
| `/item/foo%2Fbar` | `/item/foo/bar` — refresh/share resolves to a
different route | `/item/foo%2Fbar` |
| `?q=x%26y` | `?q=x&y` — value splits into two query parameters |
`?q=x%26y` |
| `?color=%23ffffff` | `?color=#ffffff` — rest of the URL becomes a
fragment | `?color=%23ffffff` |

Because routers decode path parameters exactly once, this also made
`GoRouterState.pathParameters` differ between in-app navigation and a
subsequent
browser refresh of the same URL: each round trip through the engine
silently
dropped one encoding level.

## Fix

`handleNavigationMessage` keeps the scheme/authority stripping, but now
reassembles
the URL from the raw (still encoded) `path`, `query`, and `fragment`
components
instead of decoding the result. The browser's address bar now reflects
exactly what
the framework reported.

This supersedes flutter#176029, which was closed for inactivity (missing
tests). Unlike
that attempt, this PR also avoids reconstructing the query via
`Uri(queryParameters:)`, which re-encoded values differently than
reported
(e.g. `%20` in a query value came back as `+`), and it adds a regression
test.

## Tests

Adds a regression test to `lib/web_ui/test/engine/routing_test.dart`
asserting
that `%20`, `%2F`, and `%26` in path, query, and fragment survive the
round trip
into browser history unchanged. The existing `routeInformationUpdated
can handle
uri` test (scheme/authority stripping) is unaffected and still passes.

Fixes flutter#180373
Fixes flutter#171757
Fixes flutter#147857
Fixes flutter#155992

cc @mdebbar (you triaged flutter#176029 and invited a re-open — this picks that
up with tests)

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [AI contribution guidelines] and understand my
responsibilities, or I am not using AI tools.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

If this change needs to override an active code freeze, provide a
comment explaining why. The code freeze workflow can be overridden by
code reviewers. See pinned issues for any active code freezes with
guidance.

**Note**: The Flutter team is currently trialing the use of [Gemini Code
Assist for
GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code).
Comments from the `gemini-code-assist` bot should not be taken as
authoritative feedback from the Flutter team. If you find its comments
useful you can update your code accordingly, but if you are unsure or
disagree with the feedback, please feel free to wait for a Flutter team
member's review for guidance on which automated comments should be
addressed.

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[AI contribution guidelines]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

---------

Co-authored-by: Mouad Debbar <[email protected]>
Co-authored-by: zhongliugo <[email protected]>