Clarify error message when Exec command lacks execution permissions

[ilolipopi]

Clarify error message when Exec command lacks execution permissions

Problem Description

When the command specified in the Exec field in a .desktop file exists but does not have execution permissions, Menulibre shows the following error:

Unknown error. Desktop file appears to be valid.

This message is vague and does not help users identify the root cause of the problem. It can cause confusion, especially when the .desktop file syntax is correct.

Suggested Improvement

Update the error message to explicitly indicate that the command exists but lacks execution permissions. For example:

• "Error: The command specified in the Exec field exists but does not have execution permissions. Please check the file permissions."

Steps to Reproduce

1. Set the Exec field to a valid command that lacks execution permissions. Example:
2. Open Menulibre the changes.
3. "Invalid desktop files detected! Please see details." and then "Unknown error. Desktop file appears to be valid.", which is not datailed at all.

Expected Behavior

The error message should clearly explain the actual issue to help users resolve it. For example:

• "Error: The Exec command exists but cannot be executed due to missing permissions. Please use chmod +x /path/to/command to fix this issue."

Additional Context

Improving this error message will:

1. Help users quickly diagnose and fix the problem.
2. Enhance the overall user experience for Menulibre.

Thank you for your consideration!