Navigation to parent commit's files is not working properly

Steps to reproduce:

• Navigate to a changeset via /commits/30e07f77ab9ee6cb62dd92f016db4f6433b1beb9
• Click on a link to navigate to parent commit on right hand side
• Current url is /commits/689684ad229b5f1a6491fc2501a25c4fb8489c88
• Click on Files tab

Expected:

• /browse?at=689684ad229b5f1a6491fc2501a25c4fb8489c88

Actual:

• /browse?at=30e07f77ab9ee6cb62dd92f016db4f6433b1beb9