In `scss-mode', when comments have "t" or "T" as the first characters
in the comment, it is regarded as part of the comment.

For instance, if the following comment is filled with `fill-column'
set to 20:

  // This comment begins with the character "T"

the following happens:

  // This comment
  // Tbegins with the
  // Tcharacter "T"


The following change seems to fix this bug:

diff --git a/lisp/textmodes/css-mode.el b/lisp/textmodes/css-mode.el
index 1759643..35c5ba9 100644
--- a/lisp/textmodes/css-mode.el
+++ b/lisp/textmodes/css-mode.el
@@ -459,7 +459,7 @@
   "Major mode to edit \"Sassy CSS\" files."
   (setq-local comment-start "// ")
   (setq-local comment-end "")
-  (setq-local comment-start-skip "/[*/]+[ t]*")
+  (setq-local comment-start-skip "/[*/]+[ \t]*")
   (setq-local comment-end-skip "[ \t]*\\(?:\n\\|\\*+/\\)")
   (setq-local font-lock-defaults '(scss-font-lock-keywords nil t)))


In GNU Emacs 25.0.50.4 (x86_64-unknown-linux-gnu, GTK+ Version 3.14.5)
 of 2014-12-24 on x240
Repository revision: e55a467ec0f758c311d358ceb7d66a8a7d9482c3
Windowing system distributor `The X.Org Foundation', version 
11.0.11602901
System Description:	Debian GNU/Linux 8.0 (jessie)

Configured using:
 `configure --without-makeinfo'

Configured features:
XPM JPEG TIFF GIF PNG SOUND DBUS GSETTINGS NOTIFY LIBXML2 FREETYPE XFT
ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message dired format-spec
rfc822 mml easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse
rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045
ietf-drums mm-util help-fns mail-prsvr mail-utils time-date tooltip
eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel x-win
x-dnd tool-bar dnd fontset image regexp-opt fringe tabulated-list
newcomment elisp-mode lisp-mode prog-mode register page menu-bar
rfn-eshadow timer select scroll-bar mouse jit-lock font-lock syntax
facemenu font-core frame cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese hebrew greek romanian slovak
czech european ethiopic indian cyrillic chinese case-table epa-hook
jka-cmpr-hook help simple abbrev minibuffer nadvice loaddefs button
faces cus-face macroexp files text-properties overlay sha1 md5 base64
format env code-pages mule custom widget hashtable-print-readable
backquote make-network-process dbusbind gfilenotify dynamic-setting
system-font-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty emacs)

Memory information:
((conses 16 74912 6107)
 (symbols 48 17911 0)
 (miscs 40 42 124)
 (strings 32 10939 5181)
 (string-bytes 1 295851)
 (vectors 16 9353)
 (vector-slots 8 386601 16211)
 (floats 8 70 63)
 (intervals 56 174 0)
 (buffers 976 11)
 (heap 1024 47819 1042))