Fix directory path validation checks

[paudelritij]

Closes #13017
Follow-up to #12867

1.validateDirectory() method was not handling relative path correctly.
2. While assigning 'valid relative path' then pressing folder icon, getBrowseDirectory() method was not checking the 'valid provided directory path' properly.

Fix: paths now will be resolve against library working directory.

Mandatory checks

• I own the copyright of the code submitted and I license it under the MIT license
• Change in CHANGELOG.md described in a way that is understandable for the average user (if change is visible to the user)
• [/] Tests created for changes (if applicable)
• Manually tested changed features in running JabRef (always required)
• [/] Screenshots added in PR description (if change is visible to the user)
• Checked developer's documentation: Is the information available and up to date? If not, I outlined it in this pull request.
• Checked documentation: Is the information available and up to date? If not, I created an issue at https://github.com/JabRef/user-documentation/issues or, even better, I submitted a pull request to the documentation repository.

[paudelritij]

@koppor I found I had not added proper validation message for unsaved library while working on #11840. Shall I add it to current PR (msg like 'Save the library to perform this action') since few lines of code ? or need new PR if we want to disable the field with dir icon since lib not saved.

[koppor]

@koppor I found I had not added proper validation message for unsaved library while working on #11840.

Oh, this is unfortunate.

I think, I commented. But I have no time to search.

If libPath is empty, use configDir. No need for an error message. Only making the configDir path relative to the bib path won't work.

Maybe, we need a UML state chart to visualize. I remember, I commented somehow about the global setting to store PDFs relative to the bib file, but I don't know if in the context of this.

Shall I add it to current PR (msg like 'Save the library to perform this action') since few lines of code ? or need new PR if we want to disable the field with dir icon since lib not saved.

Both is wrong IMHO. Absolute paths always work.

[koppor]

Small typos in the code.

Need to try out later.

[koppor]

Tried it out - works.

[trag-bot]

@trag-bot didn't find any issues in the code! ✅✨

[trag-bot]

@trag-bot didn't find any issues in the code! ✅✨