REST API JavaScript Client: Support an empty string for nonce

[ocean90]

Related to #43265, #40422.

Example:

myApi = wp.api.init( {
        versionString: 'my-api/v1/'
        nonce: ''
} );

In this case I don't want the client to include a nonce in requests at all. But because of the args.nonce || wpApiSettings.nonce || '' line it always falls back to wpApiSettings.nonce.

A use case would be a read-only endpoint on another site in a multisite.

[ocean90]

Fall back to empty string if wpApiSettings.nonce isn't set.

[ocean90]

Moving to 4.9.5 to follow #42948.

@adamsilverstein What's missing here?

[adamsilverstein]

@ocean90 looks good, nothing missing. I’m afk for a week, feel free to commit.

[ocean90]

In 42852:

REST API JavaScript Client: Support an empty string for nonce to disable sending the X-WP-Nonce header.

Passing a nonce argument with an empty string to wp.api.init() now does no longer fall back to wpApiSettings.nonce. This makes it possible to stop sending nonce headers, for example to a read-only endpoint on another site in a multisite install.

Props adamsilverstein, FPCSJames, ocean90, swissspidy.
Fixes #42948, #43266.

[ocean90]

In 42854:

REST API JavaScript Client: Support an empty string for nonce to disable sending the X-WP-Nonce header.

Passing a nonce argument with an empty string to wp.api.init() now does no longer fall back to wpApiSettings.nonce. This makes it possible to stop sending nonce headers, for example to a read-only endpoint on another site in a multisite install.

Merge of [42852] to the 4.9 branch.

Props adamsilverstein, FPCSJames, ocean90, swissspidy.
See #42948, #43266.