Incorrect nested home directory detection in installer

We have a Stash instance running version 3.6.1 (Java jdk1.8.0_31) on RHEL 6.6 but when trying to upgrade to Stash version 3.7.1 using the package binary (atlassian-stash-3.7.1-x64.bin) the installation script now fails to recognise our STASH_INSTALL and STASH_HOME as two separate parent directories and as a consequence refuse to continue with the upgrade process.

We are using the following directory structure:
STASH_INSTALL = /opt/stash
STASH_HOME = /opt/stash-data

It seems the install script fails to read the "-data" possibly due to the - and thus sees the two directories as the same.
Worth to mention is that we have successfully upgraded the Stash instance in the past without this issue so it seems down to the latest changes to the installation process.

—
Starting Installer ...

This will install Stash 3.7.1 on your computer.
OK [o, Enter], Cancel [c]

Please choose one of the following:
Install a new Stash instance [1, Enter], Upgrade an existing Stash instance [2]
2
Where should Stash be installed?

[/opt/atlassian/stash/3.7.1]
/opt/stash
Default location for Stash home directory

The location for Stash data.
Please provide the location of your existing Stash home directory, where
your repositories, plugins, and other data are stored.

Be sure to STOP your current Stash instance and create a backup before
proceeding.
[/var/atlassian/application-data/stash]
/opt/stash-data
The installation directory cannot be a parent of the home directory. Please choose another location.
Default location for Stash home directory

The location for Stash data.
Please provide the location of your existing Stash home directory, where
your repositories, plugins, and other data are stored.

Be sure to STOP your current Stash instance and create a backup before
proceeding.
[/opt/stash-data]
^C
—