1 files changed, 21 insertions, 6 deletions

diff --git a/test/manual/redisplay-testsuite.el b/test/manual/redisplay-testsuite.el
index 2175cbab1b7..defc3fee328 100644
--- a/test/manual/redisplay-testsuite.el
+++ b/test/manual/redisplay-testsuite.el
@@ -294,30 +294,45 @@ static unsigned char x_bits[] = {0xff, 0x81, 0xbd, 0xa5, 0xa5, 0xbd, 0x81, 0xff
 
   (insert "\n"))
 
-(defvar test-redisplay-5-expected-overlay nil)
-(defvar test-redisplay-5-result-overlay nil)
+(defvar test-redisplay-5a-expected-overlay nil)
+(defvar test-redisplay-5a-result-overlay nil)
+(defvar test-redisplay-5b-expected-overlay nil)
+(defvar test-redisplay-5b-result-overlay nil)
 
 (defun test-redisplay-5-toggle (_event)
   (interactive "e")
   (setq display-raw-bytes-as-hex (not display-raw-bytes-as-hex))
   (let ((label (if display-raw-bytes-as-hex "\\x80" "\\200")))
-    (overlay-put test-redisplay-5-expected-overlay 'display
+    (overlay-put test-redisplay-5a-expected-overlay 'display
+                 (propertize label 'face 'escape-glyph)))
+  (let ((label (if display-raw-bytes-as-hex "\\x3fffc" "\\777774")))
+    (overlay-put test-redisplay-5b-expected-overlay 'display
                  (propertize label 'face 'escape-glyph))))
 
 (defun test-redisplay-5 ()
   (insert "Test 5: Display of raw bytes:\n\n")
   (insert "  Expected: ")
-  (setq test-redisplay-5-expected-overlay
+  (setq test-redisplay-5a-expected-overlay
         (test-insert-overlay " " 'display
                              (propertize "\\200" 'face 'escape-glyph)))
   (insert "\n    Result: ")
-  (setq test-redisplay-5-result-overlay
+  (setq test-redisplay-5a-result-overlay
         (test-insert-overlay " " 'display "\200"))
   (insert "\n\n")
+  (insert "  Expected: ")
+  ;; This tests a large codepoint, to make sure the internal buffer we
+  ;; use to produce the representation is large enough.
+  (aset printable-chars #x3fffc nil)
+  (setq test-redisplay-5b-expected-overlay
+        (test-insert-overlay " " 'display
+                             (propertize "\\777774" 'face 'escape-glyph)))
+  (insert "\n    Result: ")
+  (setq test-redisplay-5b-result-overlay
+        (test-insert-overlay " " 'display (char-to-string #x3fffc)))
+  (insert "\n\n")
   (insert-button "Toggle between octal and hex display"
                  'action 'test-redisplay-5-toggle))
 
-
 (defun test-redisplay ()
   (interactive)
   (let ((buf (get-buffer "*Redisplay Test*")))