sharp v0.27.0 should land tomorrow with support for AVIF (see lovell/sharp#2289 (comment)).

Changed reference from 'master' to 'main' branch under DPS section in line with GitHub's recent switch from master to main branch as base repo branch names.

Co-authored-by: Luis Alvarez D. <[email protected]>
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

This makes sure redirects to the index route properly end with a trailing slash or don't based on the `trailingSlash` config to ensure an additional redirect doesn't need to take place un-necessarily. 

Fixes: #19405

This ensures we show an error for string values for `revalidate` since we currently don't handle these and instead it results in `revalidate: false` being used. This also adds tests for our `revalidate` checks to ensure they are triggered correctly and not triggered for valid values. 

x-ref: #20310

Upgraded all `http` links to `https` that support the `https` protocol.

Llinks
-----
- https://github.com/
- https://koajs.com
- https://ant.design
- https://www.carbondesignsystem.com/components/overview
- https://themes.carbondesignsystem.com
- https://knexjs.org
- https://jxnblk.com/rebass
- https://i.imgur.com/JCxtWSj.gif
- https://react.semantic-ui.com
- https://stomp.github.io
- https://videojs.com

Hi ✌️

I've seen that many people have problem with implement Google Tag Manager, I've created an example of how insert "Google Tag Manager" in a NextJs app

I've looked at the example code and saw some consistent issues related to code style. The changes applied to this PR fixes the following points:

- Differences of line breaks styles between multiple files
- Differences of if statements styles
- Unnecessary comment
- A typo on a JSDocs

---

There were line breaks between statements on `pages/index.js`
````
export async function getServerSideProps(context) {
  const { client } = await connectToDatabase()

  const isConnected = await client.isConnected() 

  return {
    props: { isConnected },
  }
}
```` 

And this wasn't being applied to the MongoDB utility:

````
export async function connectToDatabase() {
  if (cached.conn) return cached.conn
  if (!cached.promise) {
    const conn = {}
    const opts = {
      useNewUrlParser: true,
      useUnifiedTopology: true,
    }
{...}
````

And also, as shown in the snippet above, there are different styles of if statements being used. 

With that being said, the reason I made this PR is because I think that this kind of inconsistent arises questions when a contributor looks to the codebase, even if this is a simple example.

This PR fixes some typos found on examples docs

![image](https://user-images.githubusercontent.com/49720317/103223063-07b23000-4958-11eb-8bf9-09c39231a092.png)

About page import wrong pathname causing warning like this.

Change README from outdated @emotion/core to @emotion/react

Co-authored-by: Joe Haddad <[email protected]>

Normally I wouldn't make a PR for a minor version upgrade, but the 2.0.2 version contains some important performance improvements.
tailwindlabs/tailwindcss#3032

This makes sure the query isn't dropped when doing a history navigation with i18n. Additional tests have been added to ensure this is working correctly as well. 

Fixes: #20212

This makes sure we don't generate the wrong locale source variant for the rewrite requiring a `/` on the end which won't ever be added causing the rewrite to never match. Additional tests have been added to ensure this specific rewrite is working correctly. 


Fixes: #20508

This PR is an alternative to #20247 which contains tests for the expected behavior.

---

Fixes #20198
Closes #20247

* Docs typo fix

* Update docs/basic-features/environment-variables.md

Co-authored-by: Lachlan Campbell <[email protected]>

Co-authored-by: Joe Haddad <[email protected]>
Co-authored-by: Lachlan Campbell <[email protected]>
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

* Update with-msw example

* Update README

* Update examples/with-msw/README.md

* lint fix

Co-authored-by: Luis Alvarez D <[email protected]>
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

* Update with-mongodb to be TypeScript-friendly

I slightly modified the approach so TypeScript can correctly infer types without actually having to type anything but the global:

**index.d.ts**
```ts
import { Db, MongoClient } from "mongodb";

declare global {
  namespace NodeJS {
    interface Global {
      mongoCache: {
        conn: {
          client: MongoClient | null;
          db: Db | null;
        }
        promise: Promise<MongoClient> | null;
      };
    }
  }
}
```

* lint

Co-authored-by: Joe Haddad <[email protected]>

…19135)

This ensures we handle encoding/decoding for SSG prerendered/fallback pages correctly. Since we only encode path delimiters when outputting to the disk we need to match this encoding when building the `ssgCacheKey` to look-up the prerendered pages. This also fixes non-ascii prerendered paths (e.g. 商業日語) not matching correctly. 

This does not resolve 👉  #10084 and further investigation will be needed before addressing non-ascii paths for non-SSG pages. 

The encoding output was tested against https://tst-encoding-l7amu5b9c.vercel.app/ to ensure the values will match correctly on Vercel. 

Closes: #17582
Closes: #17642
x-ref: #14717

This tweaks the new i18n query history test to address intermittent failures in CI

x-ref: #19197 (comment)
x-ref: #19135 (comment)
x-ref: #20379 (comment)

This removes `import type` usage from our core files since `import type` requires a higher TypeScript version than currently expected.

Fixes: #19300

I don't think the docs should still mention the `priority` prop because the feature no longer exists since this was merged -  #19118

It certainly caught me out! 😬 #20438

Closes: #20545

Fixes: #15278

> Bug report

> When using next dev with emacs, as you develop, emacs creates symbolic link files starting with .# as lock files. Next.js seems to attempt to load these but fails, spewing out errors constantly.

Prevents dev server from crashing when emacs creates lockfiles

tested with:

- GNU Emacs 27.1
- OSX 11.1
- Node v15.4.0

[DebugEngine stopped working](styletron/styletron#366) with v9.5 since the devtool is strictly set to eval and this option is not customizable. Unfortunately there is currently no way to fix this.

This fixes `next/image` to properly ignore inherited styles applied to the `img` tag by a parent element.

Image styling should **always** be done by a wrapper element—not to the image itself!

---

Fixes #19817
Fixes #19964

* Updated example readme

* Updated with-passport example

* Updated profile page for with-passport

* Updated with-passport-and-next-connect

* Updated with-magic

* Updated with-magic readme

* Updated with-iron-session

* Updated next version in with-iron-session

Co-authored-by: Lee Robinson <[email protected]>

Sharp 0.26.3 updates prebuild-install to ^6.0.0 which fixes an incompatibility with NPM 7.

See lovell/sharp#2419 and prebuild/prebuild-install#128

Fixes #20585
Closes #20406 as it duplicates Babel dependencies
Closes #18926 as it's outdated

Fetch is always polyfilled in legacy browsers by `@next/polyfill-nomodule`, so we do not need to import unfetch for IE11 support.

Fixes #20588

Follow-up to #20357 with additional tracers.

```
images: {
    domains: ['example.com'],
    path: 'https://example.com/myaccount/',
},
```
Those `domains` and `path` look a lot alike for me and so, I was confused. I found out that the domains are ignored if the Loader is set, which makes sense.

This ensures the default path used for the `next/image` component includes the `basePath` when configured. Additional tests have also been added to ensure the image component is working correctly with `basePath` configured.

Fixes: #19711

This moves the scroll reset behavior to happen synchronously with the DOM commit, instead of a few ticks after the render completes.

This is necessary for components that read scroll state on mount.

---

Fixes #6462

This refactors to instead of throwing a specific error when a SSG data route 404s, we return it through props and render the 404 outside of the error handling flow. No additional tests have been added as existing tests should cover this. 

Closes: #19243

This ensures we detect the `basePath` correctly for the index `basePath` route when either a `hash` or a `query` are present in the provided path. This also adds this specific test to our basePath test suite. 

Fixes: #19294
Fixes: #19437
Closes: #19444

This ensures we detect domain specific locales and redirect them client-side. Tests have been added in the `i18n` suite to ensure the domain redirect is applied correctly during a client-side navigation

Fixes: #19174

Closes #20036.

Fixes #19935

This pull request makes `Router#push` and `Router#replace` function identically to `<Link />`, i.e. reset scroll when the new render is complete.

Users can opt out of this new behavior via:
```tsx
const path = '/my-page'
router.push(path, path, { scroll: false })
```

---

Fixes #3249

https://blog.twitter.com/engineering/en_us/topics/infrastructure/2019/capping-image-fidelity-on-ultra-high-resolution-devices.html

> This means that most OLED screens that say they are 3x resolution, are actually 3x in the green color, but only 1.5x in the red and blue colors. Showing a 3x resolution image in the app vs a 2x resolution image will be visually the same, though the 3x image takes significantly more data. Even true 3x resolution screens are wasteful as the human eye cannot see that level of detail without something like a magnifying glass.

> ![image](https://user-images.githubusercontent.com/616428/103366340-61b61100-4a90-11eb-9c16-8467f8930247.png)

Even the iPhone doesn't have true 3x DPI!

related: #18756

This pull request adds an `elements.delete` operation to the `useIntersection`'s cleanup function: `unobserve`.

Without this delete operation, next.js holds onto an unreachable reference of every observed element indefinitely (automatically every Link and Image is observed, so that means every rendered Link and Image element adds to the leak). I found this memory leak when building out an infinite feed in next.js with thousands of Link elements.

The final code block of the `unobserve` function body:

```tsx
  // Destroy observer when there's nothing left to watch:
  if (elements.size === 0) {
    observer.disconnect()
    observers.delete(id)
  }
```

Is effectively unreachable without this delete operation, as the `elements` map will never decrease in size as it is currently. This means that there will always be at least one IntersectionObserver instance in memory if useIntersection has been used once, regardless of if there are currently any components still using the hook.

* Update dbConnect.js

The previous logic was in my opinion prone to errors in situations when different calls to this function from different locations may happen at the same time ( like a race condition  ). If the readyState is anything but not 0, then we must not try to perform a new connection as this may cause consequent connections!

I hope this makes sense

* Update examples/with-mongodb-mongoose/utils/dbConnect.js

* Lint fix and minor changes

Co-authored-by: Luis Alvarez D <[email protected]>
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

The HTML Living Standard explicitly says `href` should be omitted to prevent the loading of an incorrectly sized image:
https://html.spec.whatwg.org/multipage/semantics.html#attr-link-imagesrcset

![image](https://user-images.githubusercontent.com/616428/103378205-8a013800-4aaf-11eb-9085-10f547263fed.png)

Since it's in the spec, I assume this is valid-enough HTML.

This also dedupes preloads which the old implementation did not.

---

Fixes #18756
x-ref #19118
Fixes #18720

Co-authored-by: Joe Haddad <[email protected]>

Follow-up to #20594 this ensures non-notFound SSG data 404s do cause a hard navigation as this signals a new deployment has occurred and a hard navigation will load the new deployment's version of the page. 

Closes: #20623

partially fixes #20341

- Makes sure that font fallback does not get repeated for every request.
- Adds a test for the same.

* bump dependencies to latest versions

* use tailwindcss class names

* use next/image component

* pass in height & width. update tailwindcss classes

* update tailwindcss classes

* mention tailwindcss 2.0

This upgrades to the version of ncc with subbundling support.

This ensures we render the locale domain on the `href` when using `next/link` previously the provided `href` was stilling being rendered which differed from the resulting `href` that was navigated to. 

Fixes: #20612

Building off [this Slack conversation](https://vercel.slack.com/archives/CGD3XGSD7/p1597329727013900), this PR adds a top-level section to the documentation on authentication patterns.

Please provide any and all comments! A few open thoughts I have:

- ~Should this include code snippets from the related providers or stay very high-level? At what point do we delegate to the examples folder?~ Keep things high level and delegate to examples folder 
- ~Should this include any related cards at the bottom?~ Added to the bottom
- ~Should other places in the documentation link back to here?~ Added link from routing
- Should it be a top-level route, or be underneath advanced?

…20633)

This pull request adjusts our experimental scroll restoration behavior to use `sessionStorage` as opposed to `History#replaceState` to track scroll position.

In addition, **it eliminates a scroll event listener** and only captures when a `pushState` event happens (thereby leaving state that needs snapshotted).

These merely adjusts implementation detail, and is covered by existing tests:
```
test/integration/scroll-back-restoration/
```

---

Fixes #16690
Fixes #17073
Fixes #20486

Adds an `isReady` field on `next/router` specifying whether the router fields are updated client-side and ready for use. Should only be used inside of `useEffect` methods and not for conditionally rendering on the server.

Closes: #8259
Closes: #9370

This example illustrates how to integrate mdbreact (material design bootstrap for react) with next.js

This bundles ally.js into Next.js itself to upgrade a dependency they have pinned.

I tried every other major focus trap solution, even those used by some modal libraries, and they all failed.

`ally.js` is the only library that can do it correctly, so we're going to stick with it.

I also removed the `maintain/disabled` as we have a backdrop that would effectively result in the same. This reduces CPU strain.

---

Fixes #19893
Fixes #14369
Closes #14372

### Don‘t use rem in react-dev-overlay.
If we create a nextjs project and use css rem. We could set the html fontsize to any 'px'.  The react-dev-overlay components styles will be affected so that the style becomes larger or smaller.

![image](https://user-images.githubusercontent.com/10840654/95490394-c189a800-09ca-11eb-816a-8bcaf6bcb657.png)
## So i suggest change the rem to px.
## After modification：
![image](https://user-images.githubusercontent.com/10840654/95490703-2e9d3d80-09cb-11eb-8369-7ec650fa6c52.png)

---

Fixes #18680

This PR fixes a bug where we'd accidentally pass-through the user-provided `srcSet` if the image was lazy, just to then replace it when we hydrate.

---

Fixes #19041

In order to get this example working, I needed to remove the invocation as described here: vercel/next-plugins#309 (comment)

* Update error when internal href and external as are used

* Update to handle error outside invariant

* Update err.sh components

This updates the blog-starter-typescript example to use the latest version of Tailwind CSS (2.0.2)

Notes:
Followed the upgrade guide here: https://tailwindcss.com/docs/upgrading-to-v2 
And Next / PostCSS guide here: https://nextjs.org/docs/advanced-features/customizing-postcss-config

Fixes #20500

This PR removes some left over traces of the `next/data` experiment, as it has been superseded by RSC.

This PR fixes a bug where `next/babel` would accidentally enable development transforms for a production build (`next build`).

This is tested by the two updated unit tests (which removed a workaround for this bug, and one now properly enables dev transforms).

---

Fixes #18929
Fixes #19001
x-ref #19046
x-ref #17032

Currently there is no way to add multiple meta tags with the same name attribute to the head of a page. This PR modifies the Head component to allow multiple meta tags with the same name if they have unique keys. 

This is important for integrating with certain services like Google Scholar and Swiftype.

Fixes #10183

Added the `locale` prop in the Link documentation. At the moment it is only stated in the i18n doc.

Follow-up to #20628 this ensures `isReady` is not initially true when the query isn't present but the page is an automatically statically optimized dynamic route

Updates the env documentation to mention `.vercelignore` when using the Vercel CLI. Also clears up parts of the other paragraphs and updates the links as these topics now have dedicated pages in the Vercel docs.