CacheStorageManager creates 'salt' file in cwd when there is no path

[Max Schmitt]

As per:

https://github.com/WebKit/WebKit/blob/1490a5c2a806d767de0b4e2dd113a35053467eea/Source/WebKit/NetworkProcess/storage/OriginStorageManager.cpp#L571

m_path

from here: https://github.com/WebKit/WebKit/blob/1490a5c2a806d767de0b4e2dd113a35053467eea/Source/WebKit/NetworkProcess/storage/CacheStorageManager.cpp#L233

can be an empty string.

This regressed in https://github.com/WebKit/WebKit/commit/5d9c260954a94cf6ce71bf69ab4b23c92b8e3e02

that a random file in the CWD with the name 'salt' gets created because the https://github.com/WebKit/WebKit/blob/1490a5c2a806d767de0b4e2dd113a35053467eea/Source/WebKit/NetworkProcess/storage/CacheStorageManager.cpp#L228 does not check if m_path is an empty string.

[Max Schmitt]

Pull Request: https://github.com/WebKit/WebKit/pull/12116

[EWS]

Committed 262291@main (8dfdc492a47b): <https://commits.webkit.org/262291@main>

Reviewed commits have been landed. Closing PR #12116 and removing active labels.

[Radar WebKit Bug Importer]

<rdar://problem/107387306>