bug#65631: Xref updates stack in case of error

[Dmitry Gutov <dmitry@gutov.dev>]

Version: 30.1

On 31/08/2023 19:33, Juri Linkov wrote:
>>>>> 1. move point to any word
>>>>> 2. type 'M-.' (xref-find-definitions)
>>>>> 3. an error is displayed correctly "No definitions found for: This"
>>>>>
>>>>> But the problem is that an unrecognized word is added to the xref stack.
>>>>> So the context menu shows "Go Back", and 'M-,' (xref-go-back) goes back
>>>>> to that word.
>>>> FWIW, I'm not sure this is necessarily a bug.  It looks like a bug in
>>>> your case, because you deliberately tricked Xref into using a word
>>>> that is definitely not a program symbol.  But that is not the case in
>>>> a more reasonable situation, where point is on a symbol, but for some
>>>> reason the symbol's definition is not found, e.g., because the TAGS
>>>> table needs to be regenerated.
>>> In case of error, point doesn't move.  So there is no need to go back.
>>
>> At this point, I was kind of feeling that this is a known-but-tolerated
>> behavior (that some might already be relying on, also known as "spacebar
>> heater" effect), but if it's still annoying, let's see about a fix.
> 
> It's not annoying, just surprises with the requirement to type extra ‘M-,’.
> 
>> How's the attached patch?
> 
> Thanks.  I expected a smaller change, but if this is still reliable,
> then why not.  At least, it works in cases that I tested.

I was looking for a smaller change, too. Thanks for testing.

Pushed to master in 17188e07ab9, closing.