Index: src/port1.0/portutil.tcl
===================================================================
--- src/port1.0/portutil.tcl	(revision 37353)
+++ src/port1.0/portutil.tcl	(working copy)
@@ -772,6 +772,10 @@
     
         close $tmpfd
     
+        if {![catch {exec diff -q $file $tmpfile >/dev/null}]} {
+            ui_warn "[format [msgcat::mc "reinplace %1\$s didn't change anything in %2\$s"] $pattern $file]"
+        }
+    
         set attributes [file attributes $file]
         # We need to overwrite this file
         if {[catch {file attributes $file -permissions u+w} error]} {