Ticket #1668: Screen and input corruption under xterm [non-UTF]

The problem:
    viewing binary files contain char 0x9A leads to massive screen corruption and Search
    dialog pops up with 1;2c search string (multiple times depending on actual screen contents).
    So it looks like the file 'presses' F7 or / and shift-right_arrow for every specified
    character combination occurrence. In case of bigger files it's impossible to exit from
    such viewer, as search dialog keeps popping up after closing.

Signed-off-by: Ilia Maslakov <il.smind@gmail.com>
Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

lib/tty/tty-slang.c

@@ -42,6 +42,7 @@
 
 #include "lib/global.h"
 #include "lib/strutil.h"        /* str_term_form */
+#include "lib/util.h"           /* is_printable() */
 
 #include "tty-internal.h"       /* slow_tty */
 #include "tty.h"
@@ -630,6 +631,8 @@ tty_print_anychar (int c)
     }
     else
     {
+        if (!is_printable (c))
+            c = '.';
         SLsmg_write_char ((SLwchar_Type) ((unsigned int) c));
     }
 }

src/filemanager/midnight.c

@@ -746,6 +746,15 @@ init_xterm_support (void)
     {
         xterm_flag = 1;
 
+#ifdef HAVE_SLANG
+        /* For 8-bit locales, NCurses handles 154 (0x9A) symbol properly, while S-Lang
+         * requires SLsmg_Display_Eight_Bit >= 154 (OR manual filtering if xterm display
+         * detected - but checking TERM would fail under screen, OR running xterm
+         * with allowC1Printable).
+         */
+        tty_display_8bit (FALSE);
+#endif
+
         /* Default to the standard xterm sequence */
         if (!xmouse_seq)
         {