Validate charset names for all charset options.

Validation is either done against mutt's table of IANA assigned names or local iconv
implementation (based on the assumption that iconv_open(charset,charset) fails if charset
is unknown to the implementation). Closes #1668.

1 files changed, 25 insertions, 0 deletions

diff --git a/charset.c b/charset.c
index 30d157e2..69c0e9bb 100644
--- a/charset.c
+++ b/charset.c
@@ -629,3 +629,28 @@ void fgetconv_close (FGETCONV **_fc)
     iconv_close (fc->cd);
   FREE (_fc);		/* __FREE_CHECKED__ */
 }
+
+int mutt_check_charset (const char *s, int strict)
+{
+  int i;
+  iconv_t cd;
+
+  if (mutt_is_utf8 (s))
+    return 0;
+
+  if (!strict)
+    for (i = 0; PreferredMIMENames[i].key; i++)
+    {
+      if (ascii_strcasecmp (PreferredMIMENames[i].key, s) == 0 ||
+	  ascii_strcasecmp (PreferredMIMENames[i].pref, s) == 0)
+	return 0;
+    }
+
+  if ((cd = mutt_iconv_open (s, s, 0)) != (iconv_t)(-1))
+  {
+    iconv_close (cd);
+    return 0;
+  }
+
+  return -1;
+}