--- ./cygwin-2.10.0-1.src/newlib-cygwin/winsup/cygwin/path.cc.ORIG	2018-05-03 19:43:00.482472100 -0400
+++ ./cygwin-2.10.0-1.src/newlib-cygwin/winsup/cygwin/path.cc	2018-05-03 20:09:44.035630700 -0400
@@ -1342,6 +1342,7 @@
 int
 normalize_win32_path (const char *src, char *dst, char *&tail)
 {
+  int drvprefixlen = 0;
   const char *src_start = src;
   bool beg_src_slash = isdirsep (src[0]);
 
@@ -1385,9 +1386,10 @@
 	*tail++ = cyg_toupper (*src++);
       else if (*src != '/')
 	{
-	  if (beg_src_slash)
-	    tail += cygheap->cwd.get_drive (dst);
-	  else if (!cygheap->cwd.get (dst, 0))
+	  if (beg_src_slash) {
+	    drvprefixlen = cygheap->cwd.get_drive (dst);
+	    tail += drvprefixlen;
+	  } else if (!cygheap->cwd.get (dst, 0))
 	    return get_errno ();
 	  else
 	    {
@@ -1423,10 +1425,10 @@
 	  else
 	    {
 	      /* Back up over /, but not if it's the first one.  */
-	      if (tail > dst + 1)
+	      if (tail > dst + 1 + drvprefixlen)
 		tail--;
 	      /* Now back up to the next /.  */
-	      while (tail > dst + 1 && tail[-1] != '\\' && tail[-2] != ':')
+	      while (tail > dst + 1 + drvprefixlen && tail[-1] != '\\' && tail[-2] != ':')
 		tail--;
 	      src += 2;
 	      /* Skip /'s to the next path component. */
@@ -1446,7 +1448,7 @@
       if ((tail - dst) >= NT_MAX_PATH)
 	return ENAMETOOLONG;
     }
-  if (tail > dst + 1 && tail[-1] == '.' && tail[-2] == '\\')
+  if (tail > dst + 1 + drvprefixlen && tail[-1] == '.' && tail[-2] == '\\')
     tail--;
   *tail = '\0';
   debug_printf ("%s = normalize_win32_path (%s)", dst, src_start);
@@ -2800,7 +2802,7 @@
 	      if (*p != '.' && *p != ' ')
 		{
 		  while (*--p != '\\')
-		    ;
+		    assert(p >= path);
 		  if (*++p != ' ')
 		    p = NULL;
 		}