Completion function hangs in REPL in multi-line editing mode

[geraldus]

Steps to reproduce:

• start REPL process
• enter multi-line edit mode, e.g. type :{ and hit RET
• type something that could be auto-completed
• invoke complete-symbol function C-M-i (or in case when company-mode enabled issue appears immediately)

[fice-t]

Seems to be a duplicate of #871. This bit me as well.

Everything seems to be screwed in multi-line mode though. One thing that would be really nice is automatic indentation inside of it...
Perhaps there should be one big issue for REPL multi-line mode?

[gracjan]

Dupe of #871. Please discuss this issue there.