[gtksourceview: 1/9] css.lang: Fix digits not allowed in vendor-specific prefix

[Christian Hergert <chergert src gnome org>]

commit 7cae0c01ff732a0cb94da746329f6543a998e41a
Author: Jeffery To <jeffery to gmail com>
Date:   Mon Jun 1 22:22:56 2020 +0800

    css.lang: Fix digits not allowed in vendor-specific prefix

 data/language-specs/css.lang | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)
---
diff --git a/data/language-specs/css.lang b/data/language-specs/css.lang
index 1d3e6829..3b2b02f9 100644
--- a/data/language-specs/css.lang
+++ b/data/language-specs/css.lang
@@ -156,12 +156,22 @@
       (?: -- | -? \%{identifier-start-char} ) \%{identifier-chars}?
     </define-regex>
 
+    <!-- identifier-chars, excluding hyphen -->
+    <define-regex id="identifier-prefix-chars" extended="true">
+      (?&gt; (?: [a-z0-9_]+ | \%{non-ascii}+ | \%{escape}+ )+ )
+    </define-regex>
+
     <!--
     https://www.w3.org/TR/CSS21/syndata.html#vendor-keywords
     https://en.wikipedia.org/wiki/CSS_hack#List_of_prefixes
     -->
     <define-regex id="vendor-specific-prefix" extended="true">
-      (?: [_-] \%{identifier-start-char}+ | mso | prince ) -
+      (?:
+        [_-] \%{identifier-start-char} \%{identifier-prefix-chars}? |
+        mso |
+        prince
+      )
+      -
     </define-regex>
 
     <define-regex id="vendor-specific-identifier" extended="true">