Bookmark Plus and pdf-tools/pdf-view error

Question

I've installed Bookmarks+ from quelpa recently, and everything was working fine until I made a minor tweak with my pdf-tools config. Now I cannot jump to bookmarks of .pdf files from any buffer, although I can see from the buffer list window that the corresponding files have been opened.

To be concrete, if I do C-x j j and select a .pdf bookmark, I get a message in the mini-buffer, which depends on what buffer I am currently viewing, although in all cases Emacs does not jump to the appropriate .pdf:

• If I am in the *Bookmark List* (or *scratch*) buffer, the message is

pdf-info--normalize-file-or-buffer: Buffer is not associated with any file :*Bookmark List*

• if I am in a buffer viewing the ~/Org/work.org file,

pdf-info-query: epdfinfo: Error opening /home/nonreligious/Org/work.org:PDF document is damaged

Again, the .pdf file appears in the list of buffers that are open. No other bookmark (to .org, .txt, dired buffers) has any issues.

I think these two issues raised on github are relevant:

• The old (politza) version of pdf-tools
• The newer (vedang) version of pdf-tools

The problem seems to be with pdf-view-bookmark-jump-handler. The second issue still being open suggests there isn't an official fix yet... but I hope someone else has come across this issue and has found a workaround.

I've tried restoring the original pdf-tools configuration and restarting emacs, but to no avail.

Using Emacs v27.2, pdf-tools-20220522.13.

Answer 1

After discussing this off-site, @Drew provided a workaround to add to one's config file

    (defun my-bmk-pdf-handler-advice (bookmark)
      (bookmark-default-handler (bookmark-get-bookmark bookmark)))

    (advice-add 'pdf-view-bookmark-jump-handler
            :after 'my-bmk-pdf-handler-advice)

with the explanation that

· In vanilla Emacs, function `bookmark--jump-via' invokes the relevant display function on the current buffer (the buffer reached by the bookmark). This is hard-coded.

· In Bookmark+ `bookmark--jump-via' doesn't do that - there's no hard-coded display of the destination buffer (there may not even be a destination buffer; jumping to a bookmark can do anything).

Instead, in Bookmark+ it's up to the particular handler for a bookmark to display (or not) the destination buffer (or anything else).

In Bookmark+ the default bookmark handler, function `bookmark-default-handler', does display the destination buffer. So if some particular handler wants that done it need only invoke the default handler when it want the display done (typically after doing its particular handling).

The problem seems to be this: The pdf-tools bookmark handler just uses set-buffer, which does nothing with respect to the display of a buffer. That function just makes a given buffer current, whether or not it's displayed anywhere and, even if it is displayed, regardless of how or where it's displayed. IOW, the PDF handler doesn't do any displaying.

The pdf-tools bookmark handler apparently depends on the buffer already being displayed. If so, the handler should ensure that it is (IMO). The PDF handler code currently apparently just tries to use the buffer of the currently `selected-window' if the destination buffer is not displayed.

As the creator/maintainer of Bookmark+, @Drew is looking into a more permanent solution to this and making the bookmark-jump-handler more consistent in its behavior, but this fix suffices for my needs.