For some edits, API action=edit with errorformat=html returns a redundant 'hookaborted' error even when an error message is set.
For example, trying to edit an UploadWizard 'Campaign' page with invalid JSON:
https://commons.wikimedia.beta.wmflabs.org/wiki/Special:ApiSandbox#action=edit&format=json&errorformat=html&title=Campaign%3Atest&text=%7B
```lang=json
{
"errors": [
{
"code": "Invalid_JSON",
"module": "edit",
"*": "\u29fcInvalid JSON\u29fd"
},
{
"code": "hookaborted",
"module": "edit",
"*": "The modification you tried to make was aborted by an extension."
}
],
"servedby": "deployment-mediawiki-09",
"*": "See https://commons.wikimedia.beta.wmflabs.org/w/api.php for API usage. Subscribe to the mediawiki-api-announce mailing list at <https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce> for notice of API deprecations and breaking changes."
}
```
(ignore the messed up error message, that's T231252, but regardless it is set and the 'hookaborted' is redundant)
I also noticed this in my work on AbuseFilter and SpamBlacklist in T229539.