tweaks: renumber a couple of symbols, and reshuffle a bit of code

Also, contract the regex for key strings.

src/nano.h

@@ -582,19 +582,19 @@ enum
 #define CONTROL_DOWN 0x404
 #define CONTROL_HOME 0x405
 #define CONTROL_END 0x406
-#define CONTROL_DELETE 0x407
+#define CONTROL_DELETE 0x40D
 #define SHIFT_CONTROL_LEFT 0x411
 #define SHIFT_CONTROL_RIGHT 0x412
 #define SHIFT_CONTROL_UP 0x413
 #define SHIFT_CONTROL_DOWN 0x414
 #define SHIFT_CONTROL_HOME 0x415
 #define SHIFT_CONTROL_END 0x416
-#define CONTROL_SHIFT_DELETE 0x417
+#define CONTROL_SHIFT_DELETE 0x41D
 #define ALT_LEFT 0x421
 #define ALT_RIGHT 0x422
 #define ALT_UP 0x423
 #define ALT_DOWN 0x424
-#define ALT_DELETE 0x427
+#define ALT_DELETE 0x42D
 #define SHIFT_ALT_LEFT 0x431
 #define SHIFT_ALT_RIGHT 0x432
 #define SHIFT_ALT_UP 0x433

src/winio.c

@@ -595,19 +595,19 @@ int parse_kbinput(WINDOW *win)
 	/* Modifiers are: Alt (8), Ctrl (4), Shift (1). */
 	if (on_a_vt && ioctl(0, TIOCLINUX, &modifiers) >= 0) {
 #ifndef NANO_TINY
+		/* Is Delete pressed together with Shift or Shift+Ctrl? */
+		if (retval == KEY_DC) {
+			if (modifiers == 0x01)
+				return SHIFT_DELETE;
+			if (modifiers == 0x05)
+				return CONTROL_SHIFT_DELETE;
+		}
 		/* Is Shift being held? */
 		if (modifiers & 0x01) {
-			/* A shifted <Tab> is a back tab. */
 			if (retval == TAB_CODE)
 				return SHIFT_TAB;
 			shift_held = TRUE;
 		}
-		/* Is Shift being held while Delete is pressed? */
-		if (modifiers == 0x01 && retval == KEY_DC)
-			return SHIFT_DELETE;
-		/* Are Ctrl and Shift being held while Delete is pressed? */
-		if (modifiers == 0x05 && retval == KEY_DC)
-			return CONTROL_SHIFT_DELETE;
 		/* Is Alt being held? */
 		if (modifiers == 0x08) {
 			if (retval == KEY_DC)

syntax/nanohelp.nanorc

@@ -5,7 +5,7 @@ syntax nanohelp
 
 # Key combos:
 color cyan "\^[]4-8A-Z^\_◀▶▲▼]"  "[◀▶▲▼]"  "\<M-."  "\<F1?[0-9]"
-color cyan "\<(Tab|Sh-Tab|Enter|Ins|Del|Sh-\^?Del|Space|Bsp|Up|Down|Left|Right|Home|End|PgUp|PgDn)\>"
+color cyan "\<((Sh-)?Tab|Enter|Ins|(Sh-\^?)?Del|Space|Bsp|Up|Down|Left|Right|Home|End|PgUp|PgDn)\>"
 
 # Quoted indicators:
 color brightred "'(\^|M-)'"