Description:
(translating from a Spanish language installation, words in English version might be different, hope you get the point).

In libreoffice writer While in Options > Internet > Mail program is empty, it stills detects the default application for mailing, like some other programs also do (thinking in firefox when an e-mail link is clicked it pop ups the thunderbird program).

So when we want to send document by mail, it will open (in my case thunderbird) but, and here is the problem, it won't attach the document.

If the Option > Internet > Mail is filled with the mail program we want to use, it doesn't defaults, since we are explicitily mentioning which mail program to use. Then when we send by mail the document, it opens the mail program and attachs de document.

It will be convenient, since it is detecting the default mailing program (even when it is not explicitily configured in Options > Internet > mail program), that also attachs the document in the mail to be send.

For the user, it feels like a bug, because the mail pops but no file or document is attached. Most users don't feel the need to configure the option since the mailing program gets detected.

Steps to Reproduce:
1. Save somo writer document.
2. Try to send document by mail. (Menu "Archivo > Enviar > Enviar documento por correo..." ~~ "File > Send > Send document by mail...")
3. In Menu "Herramientas > Opciones > Internet > Correo electrónico > Programa de correo:" leave it empty.
3. (En): In Menu "Tools > Options > Internet > Mail > Mail Program:" leave it empty.

Actual Results:  
The mail program opens but no file is attached (it seems it gets detected as default mail program)

Expected Results:
The file with the document should be attached.

I seems LibreOffice is good enough to detect the mail program, so it opens it up, but then, maybe the process to attache the document as file to the program, expects the Option > Internet > Mail > Mail program parameter, if this is not configured, then It doesn't detect the default program and in consecuence it doesn't attach the document as file to the e-mail to be sent.


Reproducible: Always

User Profile Reset: No

Additional Info:
This might be a feature request, maybe not a bug, but for regular users feel like a bug.


User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:51.0) Gecko/20100101 Firefox/51.0