save (ctrl-s function) normally does not save if no changes are made. However if file timestamp has changed since opening (by someone else) prompt user to decide what to do (save or not)

src/actions.c

@@ -450,7 +450,18 @@ const char *get_file_path(char *f)
  */
 int save(int confirm)
 {
-     if(xctx->modified)
+  struct stat buf;
+  char *name = xctx->sch[xctx->currsch];
+  int force = 0;
+
+  if(!stat(name, &buf)) {
+    if(xctx->time_last_modify && xctx->time_last_modify != buf.st_mtime) {
+      force = 1;
+      confirm = 0;
+    }
+  } 
+
+  if(force || xctx->modified)
   {
     if(confirm) {
       tcleval("ask_save");