--- origsrc/lib/same.c	2016-07-15 14:47:39.000000000 -0500
+++ src/lib/same.c	2017-02-03 13:32:48.741217700 -0600
@@ -40,6 +40,13 @@
 #include "error.h"
 #include "same-inode.h"
 
+#if __CYGWIN__
+# include <sys/cygwin.h>
+# include "cygwin.h"
+# include "malloca.h"
+# include "memcasecmp.h"
+#endif
+
 #ifndef MIN
 # define MIN(a, b) ((a) < (b) ? (a) : (b))
 #endif
@@ -59,6 +66,45 @@ same_name (const char *source, const cha
     (source_baselen == dest_baselen
      && memcmp (source_basename, dest_basename, dest_baselen) == 0);
   bool compare_dirs = identical_basenames;
+#if __CYGWIN__
+  /* If two names differ case-insensitively by only an '.exe' suffix,
+     do some sleuthing to see if .exe magic matters on the shorter
+     name.  Swapping the longer name to dest avoids duplication.  */
+  if (source_baselen == dest_baselen + 4)
+    {
+      char const *tmp_basename = source_basename;
+      size_t tmp_baselen = source_baselen;
+      source_basename = dest_basename;
+      source_baselen = dest_baselen;
+      dest_basename = tmp_basename;
+      dest_baselen = tmp_baselen;
+    }
+  if (source_baselen + 4 == dest_baselen
+      && !memcasecmp (dest_basename - 4, ".exe", 4)
+      && !memcasecmp (source_basename, dest_basename, source_baselen)
+      && 0 < cygwin_spelling(source))
+    dest_baselen -= 4;
+  /* Some, but not all, files are case-insensitive (depending on mount
+     options, CYGWIN=case settings, and virtual file systems).  Do
+     some sleuthing to decide whether case-insensitivity matters.  */
+  if (! compare_dirs && source_baselen == dest_baselen)
+    {
+      ssize_t wsrclen = cygwin_conv_path (CCP_POSIX_TO_WIN_W,
+                                          source, NULL, 0);
+      ssize_t wdstlen = cygwin_conv_path (CCP_POSIX_TO_WIN_W,
+                                          dest, NULL, 0);
+      char *wsrc = malloca (wsrclen);
+      char *wdst = malloca (wdstlen);
+      if (cygwin_conv_path (CCP_POSIX_TO_WIN_W, source, wsrc, wsrclen))
+        error (EXIT_FAILURE, errno, "unable to convert path name %s", source);
+      if (cygwin_conv_path (CCP_POSIX_TO_WIN_W, dest, wdst, wdstlen))
+        error (EXIT_FAILURE, errno, "unable to convert path name %s", dest);
+      if (wsrclen == wdstlen && memcasecmp (wsrc, wdst, wsrclen) == 0)
+        compare_dirs = true;
+      freea (wsrc);
+      freea (wdst);
+    }
+#endif /* __CYGWIN__ */
   bool same = false;
 
 #if ! _POSIX_NO_TRUNC && HAVE_PATHCONF && defined _PC_NAME_MAX