Bug 312967 – Two adjacent placeholders for the i18n replacement are wrongly replaced.

• Component: WebKit Extensions
• Status: RESOLVED FIXED

[Kanaru Sato]

Named placeholder substitution in WebExtensions localization (`i18n.getMessage`) fails when two placeholders are adjacent.

Step to reproduce:

- set a message in messages.json as follows:

```
  "adjacent_named": {
    "message": "$prefix$$suffix$",
    "placeholders": {
      "prefix": { "content": "$1" },
      "suffix": { "content": "$2" }
    }
  }
```

- Then call like this from JavaScript.

```
const args = ["3", "4"];
console.log(browser.i18n.getMessage("adjacent_named", args));
```

Expected Result:

- it shows `34`.


Actual result:

- it shows `3$SUFFIX$`.

[Radar WebKit Bug Importer]

<rdar://problem/175315700>

[Kanaru Sato]

See also: https://github.com/WebKit/WebKit/pull/62313

[EWS]

Committed 311769@main (9d2313b02b23): <https://commits.webkit.org/311769@main>

Reviewed commits have been landed. Closing PR #63298 and removing active labels.