bug#36486: [PATCH] Add tests for text-property-search to check prop-match-value

[Juri Linkov <juri@linkov.net>]

>> It is useful interactively to find errors fontified
>> with the error face.  Here is a better patch that
>> can read symbols as well as strings:
>
> [...]
>
>> +          (value (when property
>> +                   (read-from-minibuffer "Search for property value: "
>> +                                         nil nil t nil "nil"))))
>> +     (list property value)))
>
> I don't understand -- this will still return a symbol.  (And error out
> if you enter stuff like "foo bar".)

Yes, entering a symbol returns a symbol, entering a string
like "foo bar" returns a string "foo bar" literally.

Currently text-property-search-forward has more problems:
today I needed to search the property ‘face’ with the value
‘hi-yellow’ in the buffer with regexps highlighted by hi-lock.el.
Executing interactively:

  M-x text-property-search-forward RET face RET hi-yellow RET

failed to find the property because all hi-lock occurrences were
combined with font-lock text properties, i.e. all they had the
property ‘face’ with the value ‘(hi-yellow font-lock-keyword-face)’
and text-property-search-forward fails to find a value in the list
of values.