Fix FileUtils#urlToFile() on Windows

Under certain circumstances, on Windows, URLs are translated into
strings of the form "file:C:/..." (which the URL constructor does not
like at all) instead of "file:/C:/..." (which the URL constructor
does like).

Let's be lenient on Windows and just accept even the first form.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

src/main/java/org/scijava/util/FileUtils.java

@@ -66,6 +66,9 @@ public final class FileUtils {
 	public static final String SHORTENER_SLASH = "/";
 	public static final String SHORTENER_ELLIPSE = "...";
 
+	private final static boolean isWindows =
+		System.getProperty("os.name").startsWith("Win");
+
 	private FileUtils() {
 		// prevent instantiation of utility class
 	}
@@ -204,6 +207,9 @@ public static File urlToFile(final String url) {
 			path = path.substring(4, index);
 		}
 		try {
+			if (isWindows && path.matches("file:[A-Za-z]:.*")) {
+				path = "file:/" + path.substring(5);
+			}
 			return new File(new URL(path).toURI());
 		}
 		catch (final MalformedURLException e) {