Locate $HOME like C Git does on Windows

Java's user.home is not the same as $HOME so EGit did see the
same global configuration as C Git does.

Bug: 333269
Change-Id: Id54fc5292bf8c5a67177f9097ee692717a7df336
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

org.eclipse.jgit/src/org/eclipse/jgit/util/FS_Win32.java

@@ -96,4 +96,22 @@ class FS_Win32 extends FS {
 
 		return null;
 	}
+
+	@Override
+	protected File userHomeImpl() {
+		String home = SystemReader.getInstance().getenv("HOME");
+		if (home != null)
+			return resolve(null, home);
+		String homeDrive = SystemReader.getInstance().getenv("HOMEDRIVE");
+		if (homeDrive != null) {
+			String homePath = SystemReader.getInstance().getenv("HOMEPATH");
+			return new File(homeDrive, homePath);
+		}
+
+		String homeShare = SystemReader.getInstance().getenv("HOMESHARE");
+		if (homeShare != null)
+			return new File(homeShare);
+
+		return super.userHomeImpl();
+	}
 }