--- origsrc/src/copy.c	2023-08-29 05:39:27.000000000 -0600
+++ src/src/copy.c	2023-09-09 22:06:16.745397400 -0600
@@ -83,6 +83,10 @@
 #ifdef HAVE_LINUX_FS_H
 # include <linux/fs.h>
 #endif
+ 
+#ifdef __CYGWIN__
+# include "cygwin.h"
+#endif
 
 #if !defined FICLONE && defined __linux__
 # define FICLONE _IOW (0x94, 9, int)
@@ -1738,7 +1742,11 @@ close_src_desc:
 static bool
 same_file_ok (char const *src_name, struct stat const *src_sb,
               int dst_dirfd, char const *dst_relname, struct stat const *dst_sb,
-              const struct cp_options *x, bool *return_now)
+              const struct cp_options *x, bool *return_now
+#if __CYGWIN__
+	     , bool *case_change
+#endif
+	     )
 {
   const struct stat *src_sb_link;
   const struct stat *dst_sb_link;
@@ -1883,6 +1891,18 @@ same_file_ok (char const *src_name, stru
       if (S_ISLNK (dst_sb_link->st_mode))
         return true;
 
+#if __CYGWIN__
+      /* If the files have the same name, but differ in case, then let
+	 rename() change the case.  */
+      if (same_link && x->move_mode && same_name (src_name, dst_relname)
+	  && memcmp (last_component (src_name), last_component (dst_relname),
+		     base_len (src_name)))
+	{
+	  *case_change = true;
+	  return true;
+	}
+#endif
+
       /* It's not ok if they're distinct hard links to the same file as
          this causes a race condition and we may lose data in this case.  */
       if (same_link
@@ -2316,13 +2336,23 @@ copy_internal (char const *src_name, cha
           if (!use_lstat && nonexistent_dst < 0)
             new_dst = true;
           else if (follow_fstatat (dst_dirfd, drelname, &dst_sb, fstatat_flags)
-                   == 0)
+                   == 0
+#if __CYGWIN__
+	  /* stat("a") succeeds if "a.exe" - only identical accepted.  */
+		  && cygwin_spelling (drelname) == 0
+#endif
+		   )
             {
               have_dst_lstat = use_lstat;
               rename_errno = EEXIST;
             }
           else
             {
+#if __CYGWIN__
+	  /* only DST_RELNAME.exe exists - want non-existant DST_RELNAME.  */
+	      if (cygwin_spelling (drelname) != 0)
+		  errno = ENOENT;
+#endif
               if (errno == ELOOP && x->unlink_dest_after_failed_open)
                 /* leave new_dst=false so we unlink later.  */;
               else if (errno != ENOENT)
@@ -2340,10 +2370,17 @@ copy_internal (char const *src_name, cha
           bool return_now = false;
           bool return_val = true;
           bool skipped = false;
+#if __CYGWIN__
+          bool case_change = false;
+#endif
 
           if ((x->interactive != I_ALWAYS_NO && x->interactive != I_ALWAYS_SKIP)
               && ! same_file_ok (src_name, &src_sb, dst_dirfd, drelname,
-                                 &dst_sb, x, &return_now))
+                                 &dst_sb, x, &return_now
+#if __CYGWIN__
+				 , &case_change
+#endif
+				 ))
             {
               error (0, 0, _("%s and %s are the same file"),
                      quoteaf_n (0, src_name), quoteaf_n (1, dst_name));
@@ -2406,6 +2443,9 @@ copy_internal (char const *src_name, cha
              cp and mv treat -i and -f differently.  */
           if (x->move_mode)
             {
+#if __CYGWIN__
+             if (!case_change)
+#endif
               if (abandon_move (x, dst_name, dst_dirfd, drelname, &dst_sb))
                 {
                   /* Pretend the rename succeeded, so the caller (mv)
@@ -2572,7 +2612,11 @@ skip:
                    && ! x->move_mode
                    && (x->unlink_dest_before_opening
                        || (x->data_copy_required
-                           && ((x->preserve_links && 1 < dst_sb.st_nlink)
+                           && ((x->preserve_links && 1 < dst_sb.st_nlink
+#if __CYGWIN__
+			         && ! case_change
+#endif
+			        )
                                || (x->dereference == DEREF_NEVER
                                    && ! S_ISREG (src_sb.st_mode))))
                       ))
@@ -3407,6 +3451,24 @@ copy (char const *src_name, char const *
 {
   valid_options (options);
 
+#if __CYGWIN__
+  /* .exe magic - if src exists with an implicit .exe suffix and is
+     not a symlink, but dst does not exist and was also specified
+     without a suffix, then append .exe to dst.  */
+  int cygwin = cygwin_spelling (src_name);
+  char *p;
+  if (cygwin == 2
+      && ((p = strchr (dst_name, '\0') - 4) <= dst_name
+          || strcasecmp (p, ".exe") != 0))
+    {
+      cygwin = 3;
+      CYGWIN_APPEND_EXE (p, dst_name);
+      if ((p = strchr (dst_relname, '\0') - 4) <= dst_relname
+          || strcasecmp (p, ".exe") != 0)
+        CYGWIN_APPEND_EXE (p, dst_relname);
+    }
+#endif
+
   /* Record the file names: they're used in case of error, when copying
      a directory into itself.  I don't like to make these tools do *any*
      extra work in the common case when that work is solely to handle
@@ -3418,11 +3480,19 @@ copy (char const *src_name, char const *
   top_level_dst_name = dst_name;
 
   bool first_dir_created_per_command_line_arg = false;
-  return copy_internal (src_name, dst_name, dst_dirfd, dst_relname,
+  bool done = copy_internal (src_name, dst_name, dst_dirfd, dst_relname,
                         nonexistent_dst, nullptr, nullptr,
                         options, true,
                         &first_dir_created_per_command_line_arg,
                         copy_into_self, rename_succeeded);
+#if __CYGWIN__
+  if (cygwin == 3)
+    {
+      freea ((char *) dst_name);
+      freea ((char *) dst_relname);
+    }
+#endif
+  return done;
 }
 
 /* Set *X to the default options for a value of type struct cp_options.  */