Ticket #2169: Colors fixups for backward compability

* Restored old behaviour of A_BLINK attribute (intensity of background color instead of blinking foreground color);
 * Added function tty_use_256colors() for determine terminals with 256colors support;
 * Fixed background highlighting in NCurses and S-Lang.

Signed-off-by: Slava Zanko <slavazanko@gmail.com>

lib/tty/color-ncurses.c

@@ -174,11 +174,21 @@ tty_color_try_alloc_pair_lib (tty_color_pair_t * mc_color_pair)
         ibg = mc_color_pair->ibg;
         attr = mc_color_pair->attr;
 
-        /* In 8 color mode, change bright colors into bold */
+
-        if (COLORS == 8 && ifg >= 8 && ifg < 16)
+        /* In non-256 color mode, change bright colors into bold */
+        if (!tty_use_256colors ())
         {
-            ifg &= 0x07;
+            if (ifg >= 8 && ifg < 16)
-            attr |= A_BOLD;
+            {
+                ifg &= 0x07;
+                attr |= A_BOLD;
+            }
+
+            if (ibg >= 8 && ibg < 16)
+            {
+                ibg &= 0x07;
+                /* attr | = A_BOLD | A_REVERSE ; */
+            }
         }
 
         init_pair (mc_color_pair->pair_index, ifg, ibg);
@@ -199,7 +209,7 @@ tty_setcolor (int color)
 void
 tty_lowlevel_setcolor (int color)
 {
-    attrset (COLOR_PAIR (color) | color_get_attr (color));
+    tty_setcolor (color);
 }
 
 /* --------------------------------------------------------------------------------------------- */
@@ -211,3 +221,11 @@ tty_set_normal_attrs (void)
 }
 
 /* --------------------------------------------------------------------------------------------- */
+
+gboolean
+tty_use_256colors (void)
+{
+    return (COLORS == 256);
+}
+
+/* --------------------------------------------------------------------------------------------- */

lib/tty/color-slang.c

@@ -204,3 +204,11 @@ tty_set_normal_attrs (void)
 }
 
 /* --------------------------------------------------------------------------------------------- */
+
+gboolean
+tty_use_256colors(void)
+{
+    return (SLtt_Use_Ansi_Colors && SLtt_tgetnum ((char *) "Co") == 256);
+}
+
+/* --------------------------------------------------------------------------------------------- */

lib/tty/color.h

@@ -50,5 +50,7 @@ void tty_set_normal_attrs (void);
 
 void tty_color_set_defaults (const char *, const char *, const char *);
 
+extern gboolean tty_use_256colors(void);
+
 /*** inline functions ****************************************************************************/
 #endif /* MC_COLOR_H */

lib/tty/tty-slang.c

@@ -292,7 +292,8 @@ tty_init (gboolean slow, gboolean ugly_lines)
 
     tty_reset_prog_mode ();
     load_terminfo_keys ();
-    SLtt_Blink_Mode = 1;
+
+    SLtt_Blink_Mode = tty_use_256colors ()? 1 : 0;
 
     tty_start_interrupt_key ();
 

lib/tty/tty.h

@@ -65,15 +65,16 @@ extern int mc_tty_frm[];
 
 extern char *tty_tgetstr (const char *name);
 
-extern void tty_beep (void);
-
-/*** declarations of public functions ************************************************************/
-
-
 /* {{{ Input }}} */
 
 extern int reset_hp_softkeys;
 
+/*** declarations of public functions ************************************************************/
+
+extern void tty_beep (void);
+
+/* {{{ Input }}} */
+
 extern void tty_init (gboolean slow, gboolean ugly_lines);
 extern void tty_shutdown (void);