--- origsrc/lilypond-2.18.2/flower/file-name.cc	2014-03-17 15:29:16.000000000 +0000
+++ src/lilypond-2.18.2/flower/file-name.cc	2015-02-20 19:49:29.762829900 +0000
@@ -53,13 +53,14 @@ using namespace std;
 static string
 dos_to_posix (const string &file_name)
 {
-  char buf[PATH_MAX] = "";
-  char s[PATH_MAX] = {0};
-  file_name.copy (s, PATH_MAX - 1);
-  /* ugh: char const* argument gets modified.  */
-  int fail = cygwin_conv_to_posix_path (s, buf);
-  if (!fail)
-    return buf;
+  const char* const win32 = file_name.c_str();
+  const ssize_t size = cygwin_conv_path(CCP_WIN_W_TO_POSIX | CCP_RELATIVE, win32, NULL, 0);
+  if (size >= 0)
+  {
+    std::vector<char> posix(size, '\0');
+    if (!cygwin_conv_path(CCP_WIN_W_TO_POSIX | CCP_RELATIVE, win32, &posix[0], size))
+      return std::string(&posix[0], size);
+  }
   return file_name;
 }
 #endif /* __CYGWIN__ */