Bug 42773: Replace ~ with the original home.

In Bug 93141, Mozilla started sending users to their home when they type
~ in the URL bar.
On Linux, we change $HOME for various reason, therefore you would be
redirected to the spoofed home directory when typing ~.
So, we check if the original home directory is known, and use that,
instead.

docshell/base/URIFixup.sys.mjs

@@ -934,6 +934,10 @@ function fileURIFixup(uriString) {
   } else {
     // UNIX: Check if it starts with "/" or "~".
     attemptFixup = /^[~/]/.test(uriString);
+    const originalHome = Services.env.get("BB_ORIGINAL_HOME");
+    if (originalHome && (uriString === "~" || uriString.startsWith("~/"))) {
+      path = originalHome + path.substring(1);
+    }
   }
   if (attemptFixup) {
     try {