Add FS.detect() for detection of file system abstraction.

To give the user more control on which file system abstraction
should be used on Windows, FS.detect() may be configured
to assume a Cygwin installation or nor.

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java
index cb5c8bda542ba05f996a1479d5cb26b5dc50ef3b..9e817ca770f97da2d80b6dc5b63168b6dfb30d98 100644 (file)
--- a/org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java
@@ -52,16 +52,44 @@ public abstract class FS {
        /** The auto-detected implementation selected for this operating system and JRE. */
        public static final FS DETECTED;
 
-       static {
+       /**
+        * Auto-detect the appropriate file system abstraction, taking into account
+        * the presence of a Cygwin installation on the system. Using jgit in
+        * combination with Cygwin requires a more elaborate (and possibly slower)
+        * resolution of file system paths.
+        *
+        * @param cygwinUsed
+        *            <ul>
+        *            <li><code>Boolean.TRUE</code> to assume that Cygwin is used in
+        *            combination with jgit</li>
+        *            <li><code>Boolean.FALSE</code> to assume that Cygwin is
+        *            <b>not</b> used with jgit</li>
+        *            <li><code>null</code> to auto-detect whether a Cygwin
+        *            installation is present on the system and in this case assume
+        *            that Cygwin is used</li>
+        *            </ul>
+        *
+        *            Note: this parameter is only relevant on Windows.
+        *
+        * @return detected file system abstraction
+        */
+       public static FS detect(Boolean cygwinUsed) {
                if (FS_Win32.detect()) {
-                       if (FS_Win32_Cygwin.detect())
-                               DETECTED = new FS_Win32_Cygwin();
+                       boolean useCygwin = (cygwinUsed == null && FS_Win32_Cygwin.detect())
+                                       || Boolean.TRUE.equals(cygwinUsed);
+
+                       if (useCygwin)
+                               return new FS_Win32_Cygwin();
                        else
-                               DETECTED = new FS_Win32();
+                               return new FS_Win32();
                } else if (FS_POSIX_Java6.detect())
-                       DETECTED = new FS_POSIX_Java6();
+                       return new FS_POSIX_Java6();
                else
-                       DETECTED = new FS_POSIX_Java5();
+                       return new FS_POSIX_Java5();
+       }
+
+       static {
+               DETECTED = detect(null);
        }
 
        private final File userHome;