multi directional arrows with mixed types don't work

[816-8055]

When using different arrow types on multi directional arrows only the second head is rendered and the length is increased:

flowchart LR
    A o--> B
    B x--o C
    C <--x D
    E <--> F

see in live editor

[Xyz00777]

In addition to the above, when you add text in between, then there are no arrows at all

flowchart LR
    A o--> B
    A o-- test1 --> B
    B x--o C
    B x-- test2 --o C
    C <--x D
    C <-- test3 --x D
    E <--> F
    E <-- test4 --> F

Live editor

[aliouas]

I am new to Mermaid and I will be working on this issue hoping to make my first contribution.