Dmitry Gutov <dmitry@gutov.dev> writes:

> Spencer, hi,
>
> On 11/08/2025 19:44, Spencer Baugh wrote:
>> Improve completion-pcm-leading-wildcard by actually inserting
>> a * when try-completion runs.  completion-pcm--merge-try will
>> automatically remove the wildcard anywhere that it has no
>> matches, so the * is inserted only where it actually had an
>> effect.
>
> Would it be difficult to add a test for this?
>
> I can see that you authored some of most recent ones in
> minibuffer-tests.el, but completion-pcm-leading-wildcard does not seem
> to be exercised in our suite yet.

Certainly, easy enough to do a basic test, attached.

Though, after working on this some more, I think there's a better thing
to be doing here, which should always apply to pcm rather than be
conditioned on completion-pcm-leading-wildcard: insert a * when a non-*
wildcard is matching against an empty string.

For example, when doing (completion-pcm-try-completion "a/b" '("a/bbb"
"a-test/bbb") nil 3) return "a*/bbb" instead of the current "a/bbb".

This matches up with this comment in completion-pcm--merge-completions:

  ;; FIXME: in some cases, it may be necessary to turn an
  ;; `any' into a `star' because the surrounding context has
  ;; changed such that string->pattern wouldn't add an `any'
  ;; here any more.

I tried doing that change instead, and it works pretty nicely, but
before landing it I found I had to fix bug#79265 first.  So let's settle
that one first then come back to this bug.