diff --git a/src/Base/FileInfo.cpp b/src/Base/FileInfo.cpp
index 51cb32ba95..41847d6e7c 100644
--- a/src/Base/FileInfo.cpp
+++ b/src/Base/FileInfo.cpp
@@ -51,6 +51,8 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <cstdio>
+#include <cerrno>
+#include <cstring>
 
 using namespace Base;
 
@@ -280,6 +282,14 @@ std::string FileInfo::extension () const
     return FileName.substr(pos+1);
 }
 
+std::string FileInfo::completeExtension () const
+{
+    std::string::size_type pos = FileName.find_first_of('.');
+    if (pos == std::string::npos)
+        return std::string();
+    return FileName.substr(pos+1);
+}
+
 bool FileInfo::hasExtension (const char* Ext) const
 {
 #if defined (FC_OS_WIN32)
@@ -469,6 +479,10 @@ bool FileInfo::renameFile(const char* NewName)
 #else
 #   error "FileInfo::renameFile() not implemented for this platform!"
 #endif
+    if (!res) {
+        int code = errno;
+        std::clog << "Error in renameFile: " << strerror(code) << " (" << code << ")" << std::endl;
+    }
 
     return res;
 }
diff --git a/src/Base/FileInfo.h b/src/Base/FileInfo.h
index fe6c0bf3c2..60d1d71dcc 100644
--- a/src/Base/FileInfo.h
+++ b/src/Base/FileInfo.h
@@ -69,20 +69,24 @@ public:
     std::string fileNamePure () const;
     /// Convert the path name into a UCS-2 encoded wide string format.
     std::wstring toStdWString() const;
-    /** Returns the file's extension name.
-     * If complete is true (the default), extension() returns the string of all
-     * characters in the file name after (but not including) the first '.' character.
-     * If complete is false, extension() returns the string of all characters in
-     * the file name after (but not including) the last '.' character.
-     * Example:
+    /** Returns the extension of the file.
+     * The extension consists of all characters in the file after (but not including)
+     * the last '.' character.
      *@code
      *  FileInfo fi( "/tmp/archive.tar.gz" );
-     *  std::string ext = fi.extension(true);  // ext = "tar.gz"
-     *  ext = fi.extension(false);   // ext = "gz"
      *  ext = fi.extension();   // ext = "gz"
      *@endcode
      */
     std::string extension () const;
+    /** Returns the complete extension of the file.
+     * The complete extension consists of all characters in the file after (but not including)
+     * the first '.' character.
+     *@code
+     *  FileInfo fi( "/tmp/archive.tar.gz" );
+     *  ext = fi.completeExtension();   // ext = "tar.gz"
+     *@endcode
+     */
+    std::string completeExtension () const;
     /// Checks for a special extension, NOT case sensetive
     bool hasExtension (const char* Ext) const;
     //@}