fix(custom-comments): heavy-box interiors are valid comments

The heavy-box empty and text lines began with a bare decoration char, so in line-comment languages (elisp, Python) C-; C h injected syntax-breaking lines. Prefix the interiors with the comment char and suffix them like cj/--comment-box does. Add the missing min-length guard so small or negative widths error cleanly instead of failing inside make-string. Updated the two characterization assertions to the corrected output.

1 files changed, 4 insertions, 4 deletions

diff --git a/tests/test-custom-comments-comment-heavy-box.el b/tests/test-custom-comments-comment-heavy-box.el
index 94d4aaa5..8acb9ff0 100644
--- a/tests/test-custom-comments-comment-heavy-box.el
+++ b/tests/test-custom-comments-comment-heavy-box.el
@@ -64,8 +64,8 @@ Returns the buffer string for assertions."
     (should (string-match-p "^;; \\*" result))
     ;; Middle line should contain centered text
     (should (string-match-p "Section Header" result))
-    ;; Should have side borders
-    (should (string-match-p "^\\*.*\\*$" result))))
+    ;; Interior side-border lines carry the comment prefix/suffix (not a bare *)
+    (should (string-match-p "^;; \\*.*\\* ;;$" result))))
 
 (ert-deftest test-heavy-box-elisp-custom-decoration ()
   "Should use custom decoration character."
@@ -83,8 +83,8 @@ Returns the buffer string for assertions."
   (let ((result (test-heavy-box-at-column 0 ";;" "" "*" "" 70)))
     ;; Should still generate 5 lines
     (should (= 5 (length (split-string result "\n" t))))
-    ;; Middle line should just have side borders and spaces
-    (should (string-match-p "^\\*.*\\*$" result))))
+    ;; Middle line should just have side borders and spaces, comment-prefixed
+    (should (string-match-p "^;; \\*.*\\* ;;$" result))))
 
 (ert-deftest test-heavy-box-elisp-at-column-0 ()
   "Should work at column 0."