diff --git a/ChangeLog b/ChangeLog
index 1da3ba2f1..5f6ff826b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2012-08-27  Richard Frith-Macdonald <rfm@gnu.org>
+
+        * Source/NSSstring.m: ([-stringByAppendingPathComponent:]) fix for
+	append to an empty string with a windows path as an argument.
+
 2012-08-26  Niels Grewe <niels.grewe@halbordnung.de>
 
 	*  configure.ac: Check for sys/filio.h and whether we need to
diff --git a/Source/NSString.m b/Source/NSString.m
index 804388b8f..de7d6dc01 100644
--- a/Source/NSString.m
+++ b/Source/NSString.m
@@ -3846,33 +3846,7 @@ static NSFileManager *fm = nil;
   unsigned	root;
   unichar	buf[length+aLength+1];
 
-  /* If the 'component' has a leading path separator (or drive spec
-   * in windows) then we need to find its length so we can strip it.
-   */
   root = rootOf(aString, aLength);
-  if (root > 0)
-    {
-      unichar c = [aString characterAtIndex: 0];
-
-      if (c == '~')
-        {
-	  root = 0;
-	}
-      else if (root > 1 && pathSepMember(c))
-        {
-	  int	i;
-
-	  for (i = 1; i < root; i++)
-	    {
-	      c = [aString characterAtIndex: i];
-	      if (!pathSepMember(c))
-	        {
-		  break;
-		}
-	    }
-	  root = i;
-	}
-    }
 
   if (length == 0)
     {
@@ -3881,6 +3855,33 @@ static NSFileManager *fm = nil;
     }
   else
     {
+      /* If the 'component' has a leading path separator (or drive spec
+       * in windows) then we need to find its length so we can strip it.
+       */
+      if (root > 0)
+	{
+	  unichar c = [aString characterAtIndex: 0];
+
+	  if (c == '~')
+	    {
+	      root = 0;
+	    }
+	  else if (root > 1 && pathSepMember(c))
+	    {
+	      int	i;
+
+	      for (i = 1; i < root; i++)
+		{
+		  c = [aString characterAtIndex: i];
+		  if (!pathSepMember(c))
+		    {
+		      break;
+		    }
+		}
+	      root = i;
+	    }
+	}
+
       [self getCharacters: buf range: ((NSRange){0, length})];
 
       /* We strip back trailing path separators, and replace them with
@@ -3912,36 +3913,42 @@ static NSFileManager *fm = nil;
       root = rootOf(self, originalLength);
     }
 
-  // Trim trailing path separators
-  while (length > 1 && pathSepMember(buf[length-1]) == YES)
-    {
-      length--;
-    }
-
-  /* Trim multi separator sequences outside root (root may contain an
-   * initial // pair if it is a windows UNC path).
-   */
   if (length > 0)
     {
+      /* Trim trailing path separators as long as they are not part of
+       * the root. 
+       */
       aLength = length - 1;
-      while (aLength > root)
+      while (aLength > root && pathSepMember(buf[aLength]) == YES)
 	{
-	  if (pathSepMember(buf[aLength]) == YES)
-	    {
-	      buf[aLength] = pathSepChar();
-	      if (pathSepMember(buf[aLength-1]) == YES)
-		{
-		  unsigned	pos;
-
-		  buf[aLength-1] = pathSepChar();
-		  for (pos = aLength+1; pos < length; pos++)
-		    {
-		      buf[pos-1] = buf[pos];
-		    }
-		  length--;
-		}
-	    }
 	  aLength--;
+	  length--;
+	}
+
+      /* Trim multi separator sequences outside root (root may contain an
+       * initial // pair if it is a windows UNC path).
+       */
+      if (length > 0)
+	{
+	  while (aLength > root)
+	    {
+	      if (pathSepMember(buf[aLength]) == YES)
+		{
+		  buf[aLength] = pathSepChar();
+		  if (pathSepMember(buf[aLength-1]) == YES)
+		    {
+		      unsigned	pos;
+
+		      buf[aLength-1] = pathSepChar();
+		      for (pos = aLength+1; pos < length; pos++)
+			{
+			  buf[pos-1] = buf[pos];
+			}
+		      length--;
+		    }
+		}
+	      aLength--;
+	    }
 	}
     }
   return [NSStringClass stringWithCharacters: buf length: length];