Add clonefile() support. Applies to original from file_cmds-457.100.3.

--- xinstall.c.orig	2025-08-23 16:18:09
+++ xinstall.c	2025-08-23 18:22:31
@@ -32,7 +32,7 @@
 
 #ifdef __APPLE__
 #ifdef TARGET_OS_OSX
-#define	WITH_DIGESTS
+/*#define	WITH_DIGESTS*/
 #endif
 #include <sys/param.h>
 #endif /* __APPLE__ */
@@ -72,7 +72,8 @@
 #ifdef __APPLE__
 #include <TargetConditionals.h>
 #include <copyfile.h>
-#include "pathnames.h"
+#include <sys/attr.h>
+#include <sys/clonefile.h>
 
 #define	st_atim	st_atimespec
 #define	st_mtim	st_mtimespec
@@ -165,6 +166,7 @@ static char *destdir, *fflags, *metafile, *tags;
 static char *destdir, *fflags, *metafile, *tags;
 #endif
 
+static int	clone(const char *, const char *, int, char *, size_t);
 static int	compare(int, const char *, size_t, int, const char *, size_t,
 		    char **);
 static char	*copy(int, const char *, int, const char *, off_t);
@@ -196,6 +198,7 @@ static int	strip(const char *, int, const char *, char
 		    const char *, const char *, off_t);
 static int	parseid(const char *, id_t *);
 static int	strip(const char *, int, const char *, char **);
+static void tempfile_template (const char *, char *, size_t);
 static void	usage(void);
 
 #ifdef __APPLE__
@@ -959,6 +962,16 @@ install(const char *from_name, const char *to_name, u_
 	}
 
 	if (!files_match) {
+		int done_clone = 0;
+		if (!devnull && !dostrip) {
+		    done_clone = (clone(from_name, to_name, 1, tempfile, sizeof(tempfile)) == 0);
+		}
+		if (done_clone &&
+		    (((to_fd = open(tempfile, O_RDONLY, 0)) < 0))) {
+		        (void)unlink(tempfile);
+		        done_clone = 0;
+		}
+		if (!done_clone) {
 		to_fd = create_tempfile(to_name, tempfile,
 		    sizeof(tempfile));
 		if (to_fd < 0)
@@ -976,17 +989,29 @@ install(const char *from_name, const char *to_name, u_
 			 */
 			if (errno == EPERM) {
 				warnx("sandbox detected, falling back to direct copy");
-				if ((!target || unlink(to_name) == 0 || errno == ENOENT) &&
-				    (to_fd = open(to_name, O_RDWR|O_CREAT|O_EXCL, mode)) >= 0) {
-					if (dostrip) {
-						stripped = strip(to_name, to_fd, from_name,
-						    &digestresult);
-					}
-					if (!stripped) {
-						digestresult = copy(from_fd, from_name, to_fd,
-						    to_name, from_sb.st_size);
+				if (!target || unlink(to_name) == 0 || errno == ENOENT) {
+				    if (!devnull && !dostrip) {
+				        done_clone = (clone(from_name, to_name, 0, NULL, 0) == 0);
+				        if (done_clone) {
+                            if ((to_fd = open(to_name, O_RDONLY, 0)) < 0) {
+                                (void)unlink(to_name);
+                            } else {
+                                digestresult = digest_file(to_name);
+                                goto copied;
+                            }
+                        }
+				    }
+				    if ((to_fd = open(to_name, O_RDWR|O_CREAT|O_EXCL, mode)) >= 0) {
+                        if (dostrip) {
+                            stripped = strip(to_name, to_fd, from_name,
+                                &digestresult);
+                        }
+                        if (!stripped) {
+                            digestresult = copy(from_fd, from_name, to_fd,
+                                to_name, from_sb.st_size);
+                        }
+                        goto copied;
 					}
-					goto copied;
 				}
 				errno = EPERM;
 				/* fall through to err() below */
@@ -1006,6 +1031,7 @@ install(const char *from_name, const char *to_name, u_
 				    tempfile, from_sb.st_size);
 			}
 		}
+		} /* !done_clone */
 	}
 
 	if (dostrip) {
@@ -1292,11 +1318,11 @@ compare(int from_fd, const char *from_name __unused, s
 }
 
 /*
- * create_tempfile --
- *	create a temporary file based on path and open it
+ * tempfile_template --
+ *	prepare a template filename for use with mktemp/mkstemp.
  */
-static int
-create_tempfile(const char *path, char *temp, size_t tsize)
+static void
+tempfile_template(const char *path, char *temp, size_t tsize)
 {
 	char *p;
 
@@ -1308,6 +1334,16 @@ create_tempfile(const char *path, char *temp, size_t t
 		p = temp;
 	(void)strncpy(p, "INS@XXXXXX", &temp[tsize - 1] - p);
 	temp[tsize - 1] = '\0';
+}
+
+/*
+ * create_tempfile --
+ *	create a temporary file based on path and open it
+ */
+static int
+create_tempfile(const char *path, char *temp, size_t tsize)
+{
+	tempfile_template(path, temp, tsize);
 	return (mkstemp(temp));
 }
 
@@ -1408,8 +1444,25 @@ done:
 		err(EX_OSERR, "fsync failed for %s", to_name);
 	}
 	return (digest_end(&ctx, NULL));
+}
+
+/*
+ * clone --
+ *	create a clone of a file
+ */
+static int
+clone(const char *from_name, const char *to_name,
+      int use_temp, char *temp_name, size_t tsize)
+{
+    if (use_temp) {
+        tempfile_template(to_name, temp_name, tsize);
+        quiet_mktemp(temp_name);
+        to_name = temp_name;
+    }
+    return clonefile(from_name, to_name, CLONE_NOOWNERCOPY);
 }
 
+
 /*
  * strip --
  *	Use strip(1) to strip the target file.