diff --git a/Source/kwsys/Glob.cxx b/Source/kwsys/Glob.cxx
index 5a96aed43..1476c25e3 100644
--- a/Source/kwsys/Glob.cxx
+++ b/Source/kwsys/Glob.cxx
@@ -223,7 +223,6 @@ void Glob::RecurseDirectory(kwsys_stl::string::size_type start,
     return;
     }
   unsigned long cc;
-  kwsys_stl::string fullname;
   kwsys_stl::string realname;
   kwsys_stl::string fname;
   for ( cc = 0; cc < d.GetNumberOfFiles(); cc ++ )
@@ -248,15 +247,6 @@ void Glob::RecurseDirectory(kwsys_stl::string::size_type start,
     fname = kwsys::SystemTools::LowerCase(fname);
 #endif
 
-    if ( start == 0 )
-      {
-      fullname = dir + fname;
-      }
-    else
-      {
-      fullname = dir + "/" + fname;
-      }
-
     bool isDir = kwsys::SystemTools::FileIsDirectory(realname);
     bool isSymLink = kwsys::SystemTools::FileIsSymlink(realname);
 
@@ -302,7 +292,6 @@ void Glob::ProcessDirectory(kwsys_stl::string::size_type start,
     return;
     }
   unsigned long cc;
-  kwsys_stl::string fullname;
   kwsys_stl::string realname;
   kwsys_stl::string fname;
   for ( cc = 0; cc < d.GetNumberOfFiles(); cc ++ )
@@ -327,19 +316,10 @@ void Glob::ProcessDirectory(kwsys_stl::string::size_type start,
     fname = kwsys::SystemTools::LowerCase(fname);
 #endif
 
-    if ( start == 0 )
-      {
-      fullname = dir + fname;
-      }
-    else
-      {
-      fullname = dir + "/" + fname;
-      }
-
     //kwsys_ios::cout << "Look at file: " << fname << kwsys_ios::endl;
     //kwsys_ios::cout << "Match: "
     // << this->Internals->TextExpressions[start].c_str() << kwsys_ios::endl;
-    //kwsys_ios::cout << "Full name: " << fullname << kwsys_ios::endl;
+    //kwsys_ios::cout << "Real name: " << realname << kwsys_ios::endl;
 
     if ( !last &&
       !kwsys::SystemTools::FileIsDirectory(realname) )
@@ -355,7 +335,7 @@ void Glob::ProcessDirectory(kwsys_stl::string::size_type start,
         }
       else
         {
-        this->ProcessDirectory(start+1, realname + "/");
+        this->ProcessDirectory(start+1, realname);
         }
       }
     }
diff --git a/Source/kwsys/SystemTools.cxx b/Source/kwsys/SystemTools.cxx
index 27082115d..bf6f458e1 100644
--- a/Source/kwsys/SystemTools.cxx
+++ b/Source/kwsys/SystemTools.cxx
@@ -250,17 +250,46 @@ inline int Chdir(const kwsys_stl::string& dir)
   return _wchdir(KWSYS_NAMESPACE::Encoding::ToWide(dir).c_str());
   #endif
 }
-inline void Realpath(const kwsys_stl::string& path, kwsys_stl::string & resolved_path)
+inline void Realpath(const kwsys_stl::string& path,
+                     kwsys_stl::string& resolved_path,
+                     kwsys_stl::string* errorMessage = 0)
 {
   kwsys_stl::wstring tmp = KWSYS_NAMESPACE::Encoding::ToWide(path);
   wchar_t *ptemp;
   wchar_t fullpath[MAX_PATH];
-  if( GetFullPathNameW(tmp.c_str(), sizeof(fullpath)/sizeof(fullpath[0]),
-                       fullpath, &ptemp) )
+  DWORD bufferLen = GetFullPathNameW(tmp.c_str(),
+      sizeof(fullpath) / sizeof(fullpath[0]),
+      fullpath, &ptemp);
+  if( bufferLen < sizeof(fullpath)/sizeof(fullpath[0]) )
     {
     resolved_path = KWSYS_NAMESPACE::Encoding::ToNarrow(fullpath);
     KWSYS_NAMESPACE::SystemTools::ConvertToUnixSlashes(resolved_path);
     }
+  else if(errorMessage)
+    {
+    if(bufferLen)
+      {
+      *errorMessage = "Destination path buffer size too small.";
+      }
+    else if(unsigned int errorId = GetLastError())
+      {
+      LPSTR message = NULL;
+      DWORD size = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER
+                                   | FORMAT_MESSAGE_FROM_SYSTEM
+                                   | FORMAT_MESSAGE_IGNORE_INSERTS,
+                                   NULL, errorId,
+                                   MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                                   (LPSTR)&message, 0, NULL);
+      *errorMessage = std::string(message, size);
+      LocalFree(message);
+      }
+    else
+      {
+      *errorMessage = "Unknown error.";
+      }
+
+    resolved_path = "";
+    }
   else
     {
     resolved_path = path;
@@ -287,15 +316,31 @@ inline int Chdir(const kwsys_stl::string& dir)
 {
   return chdir(dir.c_str());
 }
-inline void Realpath(const kwsys_stl::string& path, kwsys_stl::string & resolved_path)
+inline void Realpath(const kwsys_stl::string& path,
+                     kwsys_stl::string& resolved_path,
+                     kwsys_stl::string* errorMessage = 0)
 {
   char resolved_name[KWSYS_SYSTEMTOOLS_MAXPATH];
 
+  errno = 0;
   char *ret = realpath(path.c_str(), resolved_name);
   if(ret)
     {
     resolved_path = ret;
     }
+  else if(errorMessage)
+    {
+    if(errno)
+      {
+      *errorMessage = strerror(errno);
+      }
+    else
+      {
+      *errorMessage = "Unknown error.";
+      }
+
+    resolved_path = "";
+    }
   else
     {
     // if path resolution fails, return what was passed in
@@ -3046,10 +3091,11 @@ kwsys_stl::string SystemTools
   return "";
 }
 
-kwsys_stl::string SystemTools::GetRealPath(const kwsys_stl::string& path)
+kwsys_stl::string SystemTools::GetRealPath(const kwsys_stl::string& path,
+                                           kwsys_stl::string* errorMessage)
 {
   kwsys_stl::string ret;
-  Realpath(path, ret);
+  Realpath(path, ret, errorMessage);
   return ret;
 }
 
diff --git a/Source/kwsys/SystemTools.hxx.in b/Source/kwsys/SystemTools.hxx.in
index beb2a7e12..93cde0261 100644
--- a/Source/kwsys/SystemTools.hxx.in
+++ b/Source/kwsys/SystemTools.hxx.in
@@ -385,9 +385,12 @@ public:
   /** 
    * Get the real path for a given path, removing all symlinks.  In
    * the event of an error (non-existent path, permissions issue,
-   * etc.) the original path is returned.
+   * etc.) the original path is returned if errorMessage pointer is
+   * NULL.  Otherwise empty string is returned and errorMessage
+   * contains error description.
    */
-  static kwsys_stl::string GetRealPath(const kwsys_stl::string& path);
+  static kwsys_stl::string GetRealPath(const kwsys_stl::string& path,
+                                       kwsys_stl::string* errorMessage = 0);
 
   /**
    * Split a path name into its root component and the rest of the