PHP8 breaks passing blank values in api4

[MegaphoneJon]

Previously, I used this to fix AuthX for sites behind basic auth:

cv api4 Setting.set +v authx_header_cred=

However, in PHP8, this throws an error:

In AbstractPlusParser.php line 68:
                         
  Failed to parse JSON:  

That is because in PHP8, every string is considered to have an empty string at every position in a string.

This checks explicitly for an empty string.

That said - aren't needle and haystack reversed here?

[totten]

Confirmed -- this makes PHP8 behavior match PHP7. 👍 Added another related fix+test. Merging.

strpos('{["\'', $expr[0]) !== FALSE

That said - aren't needle and haystack reversed here?

No, but the conditional here may be unusual. It determines whether $expr[0] (ie the first character) appears in a list of JS/JSON meta-characters ({, [, ", '). So it matches a JSON object, JSON array, or JSON string.

cv api4 Setting.set +v authx_header_cred=

Aside/fun fact/bike-shed -- I'd probably do:

cv vset authx_header_cred=[]

vset and vget are just a little richer. (Ex: try cv vget /authx/ or cv vget -v authx_header_cred)