(Fcall_interactively): `+' is reserved for user changes.

1 files changed, 8 insertions, 2 deletions

diff --git a/src/callint.c b/src/callint.c
index c0787ce2913..724e37f6b38 100644
--- a/src/callint.c
+++ b/src/callint.c
@@ -367,9 +367,12 @@ Otherwise, this is done only if an arg is read using the minibuffer.")
       break;
   
   /* Handle special starting chars `*' and `@'.  Also `-'.  */
+  /* Note that `+' is reserved for user extensions.  */
   while (1)
     {
-      if (*string == '*')
+      if (*string = '+')
+        error ("`+' is not used in `interactive' for ordinary commands");
+      else if (*string == '*')
         {
           string++;
           if (!NILP (current_buffer->read_only))
@@ -614,8 +617,11 @@ Otherwise, this is done only if an arg is read using the minibuffer.")
           visargs[i] = last_minibuf_string;
           break;
 
+          /* We have a case for `+' so we get an error
+             if anyone tries to define one here.  */
+        case '+':
         default:
-          error ("Invalid control letter \"%c\" (%03o) in interactive calling string",
+          error ("Invalid control letter `%c' (%03o) in interactive calling string",
                  *tem, *tem);
         }