Multiple merges in single commit breaks commit graph

[eightfingers89]

When more that one branch is merged as part of a single commit, the text output of "git log --graph" appears something like the following:
* | | b9783c0c2
* | | c6c684cd7
| | *-------. f91f7549e Interesting commit
| | |\ \ \ \ \
| | | | | | | * 57759c11a
| | | | | | | * 9f1924f08

The parsing of the graph in public/vendor/plugins/gitgraph/gitgraph.js does not handle the "-" characters properly, resulting in an error that prevents display of commits subsequent to the line with the merge.

At line 390, changing:
color = flows[colomnIndex].color;
to:
if (colomn === "-") {
currentRow.splice(colomnIndex + 1, 1);
color = flows[colomnIndex+1].color;
}
else {
color = flows[colomnIndex].color;
}
Corrects the display, in our repository, but I am unsure of any side effects, particularly with the flows array.