I have the latest PhpStorm version (8.0.2, build PS139.732). I'm on Mac OS 10.9.5, and am using external SVN from Mac Ports v. 1.8.10 (r1615264).
I have SVN configured to use the external command, and the "Enable interactive mode" checkbox is checked. For the network, the SSL protocol is set to TLS v.1.
From the command line, I can do pretty much anything from SVN.
From within PhpStorm, SVN tends to fail. I clear the authentication from the PhpStorm preferences panel, and SVN operations eventually time out -- however, PhpStorm never asks me for credentials.
If I set PhpStorm to use the system default subversion cofniguration directory and then save my credentials from SVN operations using the command line, some PhpStorm SVN operations will succeed (updates, commits), but others will consistently fail (e.g., get history). PhpStorm will show a progress bar for "Collecting revisions history for 'xxxx.php'" and eventually time out with the error "Error:Can not get current revision for file xxxx.php"
Yet on the server side, I look at the logs, and see a successful fetch of the information: "REPORT /repo/path/details/xxxx.php HTTP/1.1" 200 206917
This used to work flawlessly, and I don't know what could have changed.