diff --git a/core/src/main/java/hudson/FilePath.java b/core/src/main/java/hudson/FilePath.java
index 0c7473f708..bede528f8a 100644
--- a/core/src/main/java/hudson/FilePath.java
+++ b/core/src/main/java/hudson/FilePath.java
@@ -185,7 +185,7 @@ public final class FilePath implements Serializable {
      */
     public FilePath(VirtualChannel channel, String remote) {
         this.channel = channel;
-        this.remote = remote;
+        this.remote = normalize(remote);
     }
 
     /**
@@ -197,7 +197,7 @@ public final class FilePath implements Serializable {
      */
     public FilePath(File localPath) {
         this.channel = null;
-        this.remote = localPath.getPath();
+        this.remote = normalize(localPath.getPath());
     }
 
     /**
@@ -209,12 +209,12 @@ public final class FilePath implements Serializable {
         this.channel = base.channel;
         if(isAbsolute(rel)) {
             // absolute
-            this.remote = rel;
+            this.remote = normalize(rel);
         } else 
         if(base.isUnix()) {
-            this.remote = base.remote+'/'+rel;
+            this.remote = normalize(base.remote+'/'+rel);
         } else {
-            this.remote = base.remote+'\\'+rel;
+            this.remote = normalize(base.remote+'\\'+rel);
         }
     }
 
@@ -224,6 +224,57 @@ public final class FilePath implements Serializable {
 
     private static final Pattern DRIVE_PATTERN = Pattern.compile("[A-Za-z]:[\\\\/].*");
 
+    /**
+     * {@link File#getParent()} etc cannot handle ".." and "." in the path component very well,
+     * so remove them.
+     */
+    private static String normalize(String path) {
+        if (path.indexOf('.')<0)    return path;    // common case
+
+        path = _normalize(path,'/');
+        path = _normalize(path,'\\');
+
+        // if the normalization results in a bare drive letter, like "C:", it needs to be fixed up to "C:\\"
+        if (path.length()==2 && path.charAt(1)==':')    path+='\\';
+        return path;
+    }
+
+    private static String _normalize(String path, char separator) {
+        List<String> tokens = new ArrayList<String>();
+        int s=0; // start of the next token
+        while (true) {
+            int idx = path.indexOf(separator,s);
+            if (idx<0) {
+                tokens.add(path.substring(s));
+                break;
+            }
+            tokens.add(path.substring(s,idx));
+            s = idx+1;
+        }
+
+        boolean modified=false;
+
+        for (int i=0; i<tokens.size(); ) {
+            String token = tokens.get(i);
+            if (token.equals(".")) {
+                tokens.remove(i);
+                modified = true;
+            } else
+            if (token.equals("..") && i>0) {
+                tokens.remove(i);
+                tokens.remove(i-1);
+                i--;
+                modified = true;
+            } else
+                i++;
+        }
+
+        if (modified)
+            path = Util.join(tokens,""+separator);
+
+        return path;
+    }
+
     /**
      * Checks if the remote path is Unix.
      */
diff --git a/core/src/test/java/hudson/FilePathTest.java b/core/src/test/java/hudson/FilePathTest.java
index c1fc0a7463..da96db52c3 100644
--- a/core/src/test/java/hudson/FilePathTest.java
+++ b/core/src/test/java/hudson/FilePathTest.java
@@ -23,6 +23,7 @@
  */
 package hudson;
 
+import hudson.remoting.VirtualChannel;
 import hudson.util.NullStream;
 
 import java.io.File;
@@ -71,4 +72,32 @@ public class FilePathTest extends ChannelTestCase {
             Util.deleteRecursive(tmp);
         }
     }
+
+    public void testNormalization() throws Exception {
+        compare("abc/def\\ghi","abc/def\\ghi"); // allow mixed separators
+
+        {// basic '.' trimming
+            compare("./abc/def","abc/def");
+            compare("abc/./def","abc/def");
+            compare("abc/def/.","abc/def");
+
+            compare(".\\abc\\def","abc\\def");
+            compare("abc\\.\\def","abc\\def");
+            compare("abc\\def\\.","abc\\def");
+        }
+
+        compare("abc/../def","def");
+        compare("abc/def/../../ghi","ghi");
+        compare("abc/./def/../././../ghi","ghi");   // interleaving . and ..
+
+        compare("../abc/def","../abc/def");     // uncollapsible ..
+        compare("abc/def/..","abc");
+
+        compare("c:\\abc\\..","c:\\");      // we want c:\\, not c:
+        compare("c:\\abc\\def\\..","c:\\abc");
+    }
+
+    private void compare(String original, String answer) {
+        assertEquals(answer,new FilePath((VirtualChannel)null,original).getRemote());
+    }
 }