1 files changed, 17 insertions, 0 deletions
diff --git a/build-aux/move-if-change b/build-aux/move-if-change
new file mode 100755
index 0000000..03dd02e
--- /dev/null
+++ b/build-aux/move-if-change
@@ -0,0 +1,17 @@
+#!/bin/sh
+# Like mv $1 $2, but if the files are the same, just delete $1.
+# Status is zero if successful, nonzero otherwise.
+#
+# Copyright (C) 2011 Free Software Foundation, Inc.
+# License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
+# This is free software: you are free to change and redistribute it.
+# There is NO WARRANTY, to the extent permitted by law."
+
+if test -r "$2" && cmp -- "$1" "$2" >/dev/null; then
+  rm -f -- "$1"
+else
+  if mv -f -- "$1" "$2"; then :; else
+    # Ignore failure due to a concurrent move-if-change.
+    test -r "$2" && cmp -- "$1" "$2" >/dev/null && rm -f -- "$1"
+  fi
+fi