Merge from origin/emacs-26

63ba73a Fix documentation of ':propertize' in mode-line-format
22aa665 Reject invalid 5-byte sequences when detecting UTF-8 encoding
0d3c358 Fix 'replace-buffer-contents' in multibyte buffers
c79a627 Update etc/NEWS for mail-source-movemail-program change
63f1dc4 Improve movemail default
0b1a2ae Delete description of deleted Customize functions
fcd66d0 Keep vc-print-log from putting point at buffer end (Bug#31764)

Conflicts:
	etc/NEWS

1 files changed, 4 insertions, 1 deletions

diff --git a/src/coding.c b/src/coding.c
index a16142a9b41..32a9df1c533 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -1225,7 +1225,10 @@ detect_coding_utf_8 (struct coding_system *coding,
       ONE_MORE_BYTE (c4);
       if (c4 < 0 || ! UTF_8_EXTRA_OCTET_P (c4))
         break;
-      if (UTF_8_5_OCTET_LEADING_P (c))
+      if (UTF_8_5_OCTET_LEADING_P (c)
+          /* If we ever need to increase MAX_CHAR, the below may need
+             to be reviewed.  */
+          && c < MAX_MULTIBYTE_LEADING_CODE)
         {
           nchars++;
           continue;