Follow up issue on metdata export to PDF

[Siedlerchr]

To do:

• Find out why Jabref fails to export metadata to the 3 pdf's i uploaded in the last comment.

• Change the error message. The following error message emerges for 3 different phenomena.

  Error while writing 'filepath\FILE.pdf':
   null
  
  Finished writing metadata for 0 file (0 skipped, 1 errors).
  

  1. When two entries are linked to the same file and both are selected for tools>write metadata to pdf files or F6, it pops for BOTH entries. Metadata is written though. The entry that was written second overwrites the data from the first entry.

     • Error message should remain, but rephrased to inform user that "During the export process, metadata from two (or more) separate entries were written to the same file".
     • Optional: somehow show which of the entries are linked to the same file.
     • Optional: Create a dialogue/preference/option that allows user to continue, abort or skip the export of metadata for separate entries that write to the same file.

  2. When metadata was written successfully to a file, on every subsequent usage of tools>write metadata to pdf files or F6, the error message pops when used on that specific file again. It is irrelevant, if metadata is written or not written, in this case. It pops regardless. When a "clean new" pdf file is used for the first time, the error message does not emerge.

     • Remove this error message. There should be the normal "OK, metadata was written successfully" instead.

  3. It pops for all definite metadata export failures. Those are the cases where i cannot observe any change in metadata that is attached to the pdf files (the 3 pdf's i uploaded in my last comment).

     • Error message should remain, but rephrased to something like: "Metadata could not be exported/written". Ideally the cause for why metadata could not be written should be included, but if the cause is unknown, the former sentence is fine i think.

Originally posted by @ThiloteE in #8278 (comment)

[ThiloteE]

Since #8332, i. does not pop an error message anymore.

Anybody who wants to work on this followup, please check out and read #8332 before starting. Thanks.