Refactor detection of Windows platform to SystemReader

Change-Id: Id0b8aef92f10572d4f1ec198e0281162fcd7ed4e

org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java

@@ -1022,8 +1022,7 @@ public class DirCacheCheckout {
 	}
 
 	private static boolean isValidPathSegment(CanonicalTreeParser t) {
-		String osName = SystemReader.getInstance().getProperty("os.name");
-		boolean isWindows = "Windows".equals(osName);
+		boolean isWindows = SystemReader.getInstance().isWindows();
 		boolean isOSX = SystemReader.getInstance().isMacOS();
 		boolean ignCase = isOSX || isWindows;
 

org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheEntry.java

@@ -724,8 +724,7 @@ public class DirCacheEntry {
 			case ':':
 				// Tree's never have a backslash in them, not even on Windows
 				// but even there we regard it as an invalid path
-				if ("Windows".equals(SystemReader.getInstance().getProperty(
-						"os.name")))
+				if (SystemReader.getInstance().isWindows())
 					return false;
 				//$FALL-THROUGH$
 			default:

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

@@ -89,7 +89,7 @@ public abstract class FS {
 	 * @return detected file system abstraction
 	 */
 	public static FS detect(Boolean cygwinUsed) {
-		if (FS_Win32.isWin32()) {
+		if (SystemReader.getInstance().isWindows()) {
 			if (cygwinUsed == null)
 				cygwinUsed = Boolean.valueOf(FS_Win32_Cygwin.isCygwin());
 			if (cygwinUsed.booleanValue())

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

@@ -46,25 +46,11 @@ package org.eclipse.jgit.util;
 
 import java.io.File;
 import java.nio.charset.Charset;
-import java.security.AccessController;
-import java.security.PrivilegedAction;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
 class FS_Win32 extends FS {
-
-	static boolean isWin32() {
-		final String osDotName = AccessController
-				.doPrivileged(new PrivilegedAction<String>() {
-					public String run() {
-						return System.getProperty("os.name");
-					}
-				});
-		return osDotName != null
-				&& StringUtils.toLowerCase(osDotName).indexOf("windows") != -1;
-	}
-
 	FS_Win32() {
 		super();
 	}

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

@@ -239,6 +239,19 @@ public abstract class SystemReader {
 		return DateFormat.getDateTimeInstance(dateStyle, timeStyle);
 	}
 
+	/**
+	 * @return true if we are running on a Windows.
+	 */
+	public boolean isWindows() {
+		String osDotName = AccessController
+				.doPrivileged(new PrivilegedAction<String>() {
+					public String run() {
+						return getProperty("os.name");
+					}
+				});
+		return osDotName.startsWith("Windows");
+	}
+
 	/**
 	 * @return true if we are running on Mac OS X
 	 */