(concat): While copying text properties, make each composition

property value a copy.

1 files changed, 13 insertions, 3 deletions

diff --git a/src/fns.c b/src/fns.c
index 680fec8cc62..b4a67b4ebe4 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -826,12 +826,22 @@ concat (nargs, args, target_type, last_special)
 
   if (num_textprops > 0)
     {
+      Lisp_Object props;
+
       for (argnum = 0; argnum < num_textprops; argnum++)
         {
           this = args[textprops[argnum].argnum];
-          copy_text_properties (make_number (textprops[argnum].from),
-                                make_number (XSTRING (this)->size), this,
-                                make_number (textprops[argnum].to), val, Qnil);
+          props = text_property_list (this,
+                                      make_number (0),
+                                      make_number (XSTRING (this)->size),
+                                      Qnil);
+          /* If successive arguments have properites, be sure that the
+             value of `composition' property be the copy.  */
+          if (argnum > 0
+              && textprops[argnum - 1].argnum + 1 == textprops[argnum].argnum)
+            make_composition_value_copy (props);
+          add_text_properties_from_list (val, props,
+                                         make_number (textprops[argnum].to));
         }
     }
   return val;