In the lastest version of nodegit I run into malloc errors when walking the commit graph.

How to reproduce

1. Download the script at https://gist.github.com/probablycorey/438c27d57d5e287ab8bb
2. Install the node_module f616833 so the script can access it.
3. Run this command (I run it on the nodegit repo):

node nodegit-bug.js /Users/corey/code/nodegit

1. Notice this output:

...
Tim Branyen
tim@tabdeveloper.com
Tim Branyen
node(38239,0x7fff78ff8310) malloc: *** error for object 0x100d008b0: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
[1]    38239 abort      node nodegit-bug.js /Users/corey/code/nodegit

Quirks

If I remove one of the console.log lines the script doesn't fail. If also fails if I console.log parts of the commit like commit.data() or commit.message()