1 files changed, 4 insertions, 0 deletions

diff --git a/src/editfns.c b/src/editfns.c
index 26d811d8f43..d5293e170c8 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -3367,6 +3367,10 @@ usage: (format STRING &rest OBJECTS)  */)
             if (*format == 'c')
               {
                 if (! SINGLE_BYTE_CHAR_P (XINT (args[n]))
+                    /* Note: No one can remeber why we have to treat
+                       the character 0 as a multibyte character here.
+                       But, until it causes a real problem, let's
+                       don't change it.  */
                     || XINT (args[n]) == 0)
                   {
                     if (! multibyte)