patch 8.1.0512: 'helplang' default is inconsistent for C and C.UTF-8
Problem: 'helplang' default is inconsistent for C and C.UTF-8.
Solution: Don't accept a value unless it starts with two letters.
diff --git a/src/ex_cmds2.c b/src/ex_cmds2.c
index 9a23f82..3a4bce8 100644
--- a/src/ex_cmds2.c
+++ b/src/ex_cmds2.c
@@ -5359,6 +5359,16 @@
#if defined(FEAT_MULTI_LANG) || defined(PROTO)
/*
+ * Return TRUE when "lang" starts with a valid language name.
+ * Rejects NULL, empty string, "C", "C.UTF-8" and others.
+ */
+ static int
+is_valid_mess_lang(char_u *lang)
+{
+ return lang != NULL && ASCII_ISALPHA(lang[0]) && ASCII_ISALPHA(lang[1]);
+}
+
+/*
* Obtain the current messages language. Used to set the default for
* 'helplang'. May return NULL or an empty string.
*/
@@ -5379,17 +5389,17 @@
# endif
# else
p = mch_getenv((char_u *)"LC_ALL");
- if (p == NULL || *p == NUL)
+ if (!is_valid_mess_lang(p))
{
p = mch_getenv((char_u *)"LC_MESSAGES");
- if (p == NULL || *p == NUL)
+ if (!is_valid_mess_lang(p))
p = mch_getenv((char_u *)"LANG");
}
# endif
# ifdef WIN32
p = gettext_lang(p);
# endif
- return p;
+ return is_valid_mess_lang(p) ? p : NULL;
}
#endif