highlight bug?

[jagrg]

Swiper erased all highlights in the *Package* buffer immediately after pressing M-x swiper. The same happened in the *EMMS playlist* buffer. Any idea?

[abo-abo]

Swiper calls font-lock-ensure (or font-lock-fontify-buffer for older Emacs) to have the
selection candidates highlighted. It should be OK to call these functions for any buffer that has
font-lock-mode on.

I think it's a problem of the corresponding mode if it bugs out after a call to font-lock-ensure.
I could add some workarounds though. What are the values of major-mode for the problematic buffers?

[jagrg]

I wasn't aware that this was the expected behavior. Would it be possible to revert the buffer to normal once the selection has been made?

[abo-abo]

Would it be possible to revert the buffer to normal once the selection has been made?

It's possible not to call font-lock-ensure for problematic major-modes.
I've already added all modes derived from magit-mode to this list.
I just need a list of major-modes which are problematic for you.

Just use M-: (eval-expression) to see what the value of major-mode is.

[jagrg]

One is package-menu-mode and the other is emms-playlist-mode.

[abo-abo]

See if the last commit solves your issue.

[jagrg]

It didn't solve. I replaced the swiper.el file with the most recent one and restarted emacs. Is there something else I need to do?

[abo-abo]

What's your Emacs version? Maybe you could also add a screenshot of the erased highlights in the
package menu.

[jagrg]

Updating via melpa fixed the problem. I'll be replacing Isearch with swiper and see how it goes. Thanks for this!

[abo-abo]

You're welcome. If the same problem comes up for another mode, just reopen this issue.

[jagrg]

I think org-agenda-mode also needs to be fixed.

[abo-abo]

Thanks!

[jagrg]

Could you also add mu4e-view-mode and mu4e-headers-mode?

[abo-abo]

Thanks.

[daimrod]

w3m-mode and elfeed-show-mode also have problem with font-lock-fontified, could you add them?

Also, given the large number of mode impacted, wouldn't it make sense not to use font-lock-ensure? Why does swipe need it and isearch doesn't? What problem does it fix? If it's more often a problem than not, wouldn't it be easier to set when font-lock-ensure should be ran instead of when not ran it?

[abo-abo]

@daimrod The issue is that for all modes where font-lock-ensure does something weird, it's the fault of that mode: they use font-lock without properly defining the syntax. So the buffer may be fontified only once and can't be refreshed.

I think it's good to keep a list of these faulty modes - it may be easier to fix them in the future. For now, I'll just add w3m-mode and elfeed-show-mode to the list.

[daimrod]

Ok. Thanks for the fix and the explanation.

[momomo5717]

When font-lock-fontify-buffer was called at emms-stream-mode, this issue occurred.

I'm unfamiliar with font-lock and text-property,
but it seems all 'face of text-property was set to nil
after running font-lock-fontify-buffer-function bound to font-lock-default-fontify-buffer as a local variable,
and (font-lock-unfontify-region (point-min) (point-max)) caused this issue.

I searched for information about font-lock-fontify-buffer-function,
and found the setting example:

(set-default 'font-lock-fontify-buffer-function 'jit-lock-refontify)

It works fine. But I'm not sure it is correct setting.

Thank you.

[abo-abo]

@momomo5717 Thanks, I excluded emms-stream-mode from the fontify list.

[momomo5717]

Thank you for adding it!

[ghost]

It seems that I found some more:

• occur-mode, for which g restore the highlight (but also update the content of the buffer);
• occur-edit-mode
• bongo-mode

I'm on 24.5.1. Thank you.

[abo-abo]

@sshbio Thanks, updated.

[ghost]

You are welcome. I think `eww-mode` is also one of those. Thank you for bthe improvements.

[ghost]

I found one more: vc-dir-mode.

We are building a list that may be useful for other package writers as well.

Again, thank you for improving swiper.

[ghost]

bongo-playlist-mode and bongo-playlist-mode buffers also loose their pretty colors.

Thank you for your previous additions. Hopefully I will get a copyright assignment, and will be able to submit pull requests.

[ghost]

This list may become pretty long! sauron-mode also seems to be one of them.

[fuxialexander]

Would you please add notmuch-tree-mode and notmuch-search-mode to the list?