Skip bidi markers in the pager and index. (closes #3827)

Curses and slang don't support them, so there's little point in
showing them or attempting to somehow deal with them.

This patch adds filtering in the pager, and changes the filtering
added in 6e0aca94cdb0 for the index to completely skip the marker.

2 files changed, 13 insertions, 6 deletions

diff --git a/mbyte.c b/mbyte.c
index 470686c9..adea5f43 100644
--- a/mbyte.c
+++ b/mbyte.c
@@ -548,14 +548,12 @@ int mutt_filter_unprintable (char **s)
     }
     if (!IsWPrint (wc))
       wc = '?';
-    /* HACK:
-     * Work around a gnu screen bug. See ticket #3827.
-     * Filter out the RIGHT-TO-LEFT and LEFT-TO-RIGHT bidi marks because
-     * they result in screen corruption.
+    /* Filter out the RIGHT-TO-LEFT and LEFT-TO-RIGHT bidi markers because
+     * they result in screen corruption.   See ticket #3827.
      */
     else if (Charset_is_utf8 &&
              ((wc == (wchar_t)0x200f) || (wc == (wchar_t)0x200e)))
-      wc = '?';
+      continue;
     k2 = wcrtomb (scratch, wc, &mbstate2);
     scratch[k2] = '\0';
     mutt_buffer_addstr (b, scratch);
diff --git a/pager.c b/pager.c
index d47842ab..3daa5d07 100644
--- a/pager.c
+++ b/pager.c
@@ -1146,10 +1146,19 @@ static int format_line (struct line_t **lineInfo, int n, unsigned char *buf,
     if (k == 0)
       k = 1;
 
-    if (Charset_is_utf8 && (wc == 0x200B || wc == 0xFEFF))
+    if (Charset_is_utf8)
     {
+      if (wc == 0x200B || wc == 0xFEFF)
+      {
 	dprint (3, (debugfile, "skip zero-width character U+%04X\n", (unsigned short)wc));
 	continue;
+      }
+      /* Filter bidi markers, see ticket #3827 */
+      if (wc == (wchar_t)0x200f || wc == (wchar_t)0x200e)
+      {
+	dprint (3, (debugfile, "skip bidi marker U+%04X\n", (unsigned short)wc));
+	continue;
+      }
     }
 
     /* Handle backspace */