fix(custom-comments): correct comment-reformat and inline-border

cj/comment-reformat printed "No region was selected" on every call, even successful ones, because the message sat outside the if. Its fill-column shrink used a raw setq and restore, so an error mid-join left fill-column permanently at -3. It now signals a user-error when there's no region and dynamically binds fill-column, which restores itself.

cj/--comment-inline-border sized the right decoration from text-length parity, leaving even-length and empty text two columns short and misaligning stacked dividers. It now fills the exact remaining width. Both fixes ship with tests, and the inline-border test asserts exact width across parities.

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/test-custom-comments-comment-inline-border.el b/tests/test-custom-comments-comment-inline-border.el
index 78e86035..305a2c7a 100644
--- a/tests/test-custom-comments-comment-inline-border.el
+++ b/tests/test-custom-comments-comment-inline-border.el
@@ -120,6 +120,16 @@ Returns the buffer string for assertions."
   (let ((result (test-inline-border-at-column 0 ";;" "" "=" "" 10)))
     (should (string-match-p ";" result))))
 
+(ert-deftest test-inline-border-elisp-fills-exact-width-all-parities ()
+  "Boundary: even, odd, and empty text all fill LENGTH exactly.
+Even-length and empty text used to come out two columns short because the
+right decoration count keyed off text-length parity instead of the remaining
+width, so stacked dividers of differing text lengths misaligned."
+  (dolist (text '("" "X" "EVEN" "ODD" "Header"))
+    (let* ((result (test-inline-border-at-column 0 ";;" "" "=" text 50))
+           (line (string-trim-right result "\n")))
+      (should (= 50 (length line))))))
+
 (ert-deftest test-inline-border-elisp-text-centering-even ()
   "Should center text properly with even length."
   (let ((result (test-inline-border-at-column 0 ";;" "" "=" "EVEN" 70)))