From 7b91d432748703921d740eec291f3bcb3e648a69 Mon Sep 17 00:00:00 2001
From: ejurgensen <espenjurgensen@gmail.com>
Date: Sun, 27 Jul 2025 22:40:33 +0200
Subject: [PATCH] [scan] Fix for platforms without fcopyfile() or
 copy_file_range()

Add @cagney's fallback copy function. Use feature tests in configure.ac for
fcopyfile() and copy_file_range().

Fixes #1901
---
 configure.ac                     |  8 +++++++-
 src/library/filescanner_ffmpeg.c | 25 +++++++++++++++++++++----
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/configure.ac b/configure.ac
index c4c2b1b4..e2c25e04 100644
--- a/configure.ac
+++ b/configure.ac
@@ -96,7 +96,13 @@ AC_SEARCH_LIBS([pthread_getthreadid_np], [pthread],
 		[Define to 1 if you have pthread_getthreadid_np])])
 AC_SEARCH_LIBS([uuid_generate_random], [uuid],
 	[AC_DEFINE([HAVE_UUID], 1,
-		[Define to 1 if you have uuid_generate_random function])])
+		[Define to 1 if you have uuid_generate_random])])
+AC_SEARCH_LIBS([copy_file_range], [c],
+	[AC_DEFINE([HAVE_COPY_FILE_RANGE], 1,
+		[Define to 1 if you have copy_file_range])])
+AC_SEARCH_LIBS([fcopyfile], [c],
+	[AC_DEFINE([HAVE_FCOPYFILE], 1,
+		[Define to 1 if you have fcopyfile])])
 
 AC_SEARCH_LIBS([log10], [m])
 AC_SEARCH_LIBS([lrint], [m])
diff --git a/src/library/filescanner_ffmpeg.c b/src/library/filescanner_ffmpeg.c
index e7d440a5..e544e582 100644
--- a/src/library/filescanner_ffmpeg.c
+++ b/src/library/filescanner_ffmpeg.c
@@ -31,9 +31,9 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 
-// For file copy
+// For file copy (fcopyfile currently Mac OSX only)
 #include <fcntl.h>
-#if defined(__APPLE__)
+#if defined(HAVE_FCOPYFILE)
 #include <copyfile.h>
 #endif
 
@@ -810,9 +810,9 @@ static int
 fast_copy(int fd_dst, int fd_src)
 {
   // Here we use kernel-space copying for performance reasons
-#if defined(__APPLE__)
+#if defined(HAVE_FCOPYFILE)
   return fcopyfile(fd_src, fd_dst, 0, COPYFILE_ALL);
-#else
+#elif defined(HAVE_COPY_FILE_RANGE)
   struct stat fileinfo = { 0 };
   ssize_t bytes_copied;
 
@@ -821,6 +821,23 @@ fast_copy(int fd_dst, int fd_src)
   if (bytes_copied < 0 || bytes_copied != fileinfo.st_size)
     return -1;
 
+  return 0;
+#else
+  unsigned char buf[4096];
+  ssize_t nr;
+
+  while (1)
+    {
+      nr = read(fd_src, buf, sizeof(buf));
+      if (nr == -1)
+	return -1;
+      else if (nr == 0)
+	return 0;
+
+      if (write(fd_dst, buf, nr) != nr)
+	return -1;
+    }
+
   return 0;
 #endif
 }