Fix fontification of outdated TeX form

* lisp/textmodes/tex-mode.el (tex-font-lock-keywords-2): End the
expression before the terminating $ in constructions like $\it
identifiername$
(bug#28277). This avoids italicising the final $ character.

This fixes the final $ of the final test case here:

$foo$
\textit{foo}
{\it foo}
$\mathit{identifiername}$
$\textit{identifiername}$
${\it identifiername}$
$\it identifiername$

1 files changed, 1 insertions, 1 deletions

diff --git a/lisp/textmodes/tex-mode.el b/lisp/textmodes/tex-mode.el
index e3d5759579a..a905d148009 100644
--- a/lisp/textmodes/tex-mode.el
+++ b/lisp/textmodes/tex-mode.el
@@ -593,7 +593,7 @@ An alternative value is \" . \", if you use a font with a narrow period."
             ;; Miscellany.
             (slash "\\\\")
             (opt " *\\(\\[[^]]*\\] *\\)*")
-            (args "\\(\\(?:[^{}&\\]+\\|\\\\.\\|{[^}]*}\\)+\\)")
+            (args "\\(\\(?:[^${}&\\]+\\|\\\\.\\|{[^}]*}\\)+\\)")
             (arg "{\\(\\(?:[^{}\\]+\\|\\\\.\\|{[^}]*}\\)+\\)"))
        (list
         ;;