Rename term->bidi and term->arabicshaping.

Those two flags had the opposite sense to what you might expect: each
one is the value of the Conf entry corresponding to the checkbox that
_disables_ the corresponding terminal feature. So term->bidi is true
if and only if bidi is _off_.

I think that confusion of naming probably contributed to the control-
flow error fixed in the previous commit, just by increasing cognitive
load until I couldn't remember which flags were set where any more! So
now I've renamed the two fields of Terminal, and the corresponding
Conf keywords, to be called "no_bidi" and "no_arabicshaping", in line
with other 'disable this feature' flags, so that it's clear what the
sense should be.

config.c

@@ -1840,10 +1840,10 @@ void setup_config_box(struct controlbox *b, bool midsession,
 		  I(CONF_no_remote_charset));
     ctrl_checkbox(s, "Disable Arabic text shaping",
 		  'l', HELPCTX(features_arabicshaping), conf_checkbox_handler,
-		  I(CONF_arabicshaping));
+		  I(CONF_no_arabicshaping));
     ctrl_checkbox(s, "Disable bidirectional text display",
 		  'd', HELPCTX(features_bidi), conf_checkbox_handler,
-		  I(CONF_bidi));
+		  I(CONF_no_bidi));
 
     /*
      * The Window panel.

putty.h

@@ -1393,8 +1393,8 @@ NORETURN void cleanup_exit(int);
     X(INT, NONE, window_border) /* in pixels */ \
     X(STR, NONE, answerback) \
     X(STR, NONE, printer) \
-    X(BOOL, NONE, arabicshaping) \
+    X(BOOL, NONE, no_arabicshaping) \
-    X(BOOL, NONE, bidi) \
+    X(BOOL, NONE, no_bidi) \
     /* Colour options */ \
     X(BOOL, NONE, ansi_colour) \
     X(BOOL, NONE, xterm_256_colour) \

settings.c

@@ -679,8 +679,8 @@ void save_open_settings(settings_w *sesskey, Conf *conf)
     write_setting_b(sesskey, "AutoWrapMode", conf_get_bool(conf, CONF_wrap_mode));
     write_setting_b(sesskey, "LFImpliesCR", conf_get_bool(conf, CONF_lfhascr));
     write_setting_b(sesskey, "CRImpliesLF", conf_get_bool(conf, CONF_crhaslf));
-    write_setting_b(sesskey, "DisableArabicShaping", conf_get_bool(conf, CONF_arabicshaping));
+    write_setting_b(sesskey, "DisableArabicShaping", conf_get_bool(conf, CONF_no_arabicshaping));
-    write_setting_b(sesskey, "DisableBidi", conf_get_bool(conf, CONF_bidi));
+    write_setting_b(sesskey, "DisableBidi", conf_get_bool(conf, CONF_no_bidi));
     write_setting_b(sesskey, "WinNameAlways", conf_get_bool(conf, CONF_win_name_always));
     write_setting_s(sesskey, "WinTitle", conf_get_str(conf, CONF_wintitle));
     write_setting_i(sesskey, "TermWidth", conf_get_int(conf, CONF_width));
@@ -1106,8 +1106,8 @@ void load_open_settings(settings_r *sesskey, Conf *conf)
     gppb(sesskey, "AutoWrapMode", true, conf, CONF_wrap_mode);
     gppb(sesskey, "LFImpliesCR", false, conf, CONF_lfhascr);
     gppb(sesskey, "CRImpliesLF", false, conf, CONF_crhaslf);
-    gppb(sesskey, "DisableArabicShaping", false, conf, CONF_arabicshaping);
+    gppb(sesskey, "DisableArabicShaping", false, conf, CONF_no_arabicshaping);
-    gppb(sesskey, "DisableBidi", false, conf, CONF_bidi);
+    gppb(sesskey, "DisableBidi", false, conf, CONF_no_bidi);
     gppb(sesskey, "WinNameAlways", true, conf, CONF_win_name_always);
     gpps(sesskey, "WinTitle", "", conf, CONF_wintitle);
     gppi(sesskey, "TermWidth", 80, conf, CONF_width);

terminal.c

@@ -1464,13 +1464,13 @@ static void set_erase_char(Terminal *term)
 void term_copy_stuff_from_conf(Terminal *term)
 {
     term->ansi_colour = conf_get_bool(term->conf, CONF_ansi_colour);
-    term->arabicshaping = conf_get_bool(term->conf, CONF_arabicshaping);
+    term->no_arabicshaping = conf_get_bool(term->conf, CONF_no_arabicshaping);
     term->beep = conf_get_int(term->conf, CONF_beep);
     term->bellovl = conf_get_bool(term->conf, CONF_bellovl);
     term->bellovl_n = conf_get_int(term->conf, CONF_bellovl_n);
     term->bellovl_s = conf_get_int(term->conf, CONF_bellovl_s);
     term->bellovl_t = conf_get_int(term->conf, CONF_bellovl_t);
-    term->bidi = conf_get_bool(term->conf, CONF_bidi);
+    term->no_bidi = conf_get_bool(term->conf, CONF_no_bidi);
     term->bksp_is_delete = conf_get_bool(term->conf, CONF_bksp_is_delete);
     term->blink_cur = conf_get_bool(term->conf, CONF_blink_cur);
     term->blinktext = conf_get_bool(term->conf, CONF_blinktext);
@@ -1564,10 +1564,10 @@ void term_reconfig(Terminal *term, Conf *conf)
      * If the bidi or shaping settings have changed, flush the bidi
      * cache completely.
      */
-    if (conf_get_bool(term->conf, CONF_arabicshaping) !=
+    if (conf_get_bool(term->conf, CONF_no_arabicshaping) !=
-	conf_get_bool(conf, CONF_arabicshaping) ||
+	conf_get_bool(conf, CONF_no_arabicshaping) ||
-	conf_get_bool(term->conf, CONF_bidi) !=
+	conf_get_bool(term->conf, CONF_no_bidi) !=
-	conf_get_bool(conf, CONF_bidi)) {
+	conf_get_bool(conf, CONF_no_bidi)) {
 	for (i = 0; i < term->bidi_cache_size; i++) {
 	    sfree(term->pre_bidi_cache[i].chars);
 	    sfree(term->post_bidi_cache[i].chars);
@@ -5058,7 +5058,7 @@ static termchar *term_bidi_line(Terminal *term, struct termline *ldata,
     int it;
 
     /* Do Arabic shaping and bidi. */
-    if (!term->bidi || !term->arabicshaping ||
+    if (!term->no_bidi || !term->no_arabicshaping ||
         (ldata->trusted && term->cols > TRUST_SIGIL_WIDTH)) {
 
 	if (!term_bidi_cache_hit(term, scr_y, ldata->chars, term->cols,
@@ -5127,10 +5127,10 @@ static termchar *term_bidi_line(Terminal *term, struct termline *ldata,
                 nbc++;
             }
 
-	    if(!term->bidi)
+	    if(!term->no_bidi)
 		do_bidi(term->wcFrom, nbc);
 
-	    if(!term->arabicshaping) {
+	    if(!term->no_arabicshaping) {
 		do_shape(term->wcFrom, term->wcTo, nbc);
             } else {
                 /* If we're not calling do_shape, we must copy the

terminal.h

@@ -297,13 +297,13 @@ struct terminal_tag {
     bool ansi_colour;
     char *answerback;
     int answerbacklen;
-    bool arabicshaping;
+    bool no_arabicshaping;
     int beep;
     bool bellovl;
     int bellovl_n;
     int bellovl_s;
     int bellovl_t;
-    bool bidi;
+    bool no_bidi;
     bool bksp_is_delete;
     bool blink_cur;
     bool blinktext;