This may occur when git diff is ran with binary changes in the diff.
Example: https://chromium-review.googlesource.com/c/chromium/src/+/1606595

Bug: 942522
Change-Id: I44caef559de44076ef394caa5abc3967db2bb0b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1607840
Auto-Submit: Raul Tambre <raul@tambre.ee>
Commit-Queue: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>