[gitk] display error for angle brackets in diff

I'm trying to report a bug that I've know about for a year and half. I first
tried to report it to this mailing list a year ago, but the message was
lost. Here's a post I made on reddit 6 months ago:
http://www.reddit.com/r/git/comments/2twvsz/please_help_me_report_this_gitk_bug_to_the_git/
 
The problem is that diffs with angle brackets are displayed incorrectly in gitk.
 
How to reproduce the bug:
 
Create a file with the following, and commit:
x < 1
y > 2
 
Modify it to this, and commit:
z < 1
w > 2
 
Then view the results with:
gitk --color-words
 
You will see:

    "Diff" shows bogus removal on 1st line and bogus addition on 2nd line.
    "Old version" cuts off at right angle bracket.
    "New Version" cuts off at left angle bracket.

I personally use a 2-line patch to fix this by disabling/breaking the feature that does string comparisons for " >" and " <", but I know that's not the correct fix, so I'm not including it in this post.