X11 extended commands menu scrolling

Support for scrolling within menus via first-/previous-/next-/last-
page keystrokes ("^<>|" by default) was added to X11's general menu
handling but the extended commands menu uses a special menu rather
than a general one.  This clones the relevant code to add support for
those keys to extended commands.

doc/fixes36.2

@@ -1,4 +1,4 @@
-$NHDT-Branch: NetHack-3.6.2-beta01 $:$NHDT-Revision: 1.295 $ $NHDT-Date: 1554134321 2019/04/01 15:58:41 $
+$NHDT-Branch: NetHack-3.6.2-beta01 $:$NHDT-Revision: 1.296 $ $NHDT-Date: 1554136021 2019/04/01 16:27:01 $
 
 This fixes36.2 file is here to capture information about updates in the 3.6.x
 lineage following the release of 3.6.1 in April 2018. Please note, however,
@@ -501,6 +501,7 @@ X11: its use of genl_status_update exposed a negative index use that could
 X11: rollback disabling of keystroke input for PICK_NONE menus (for scrolling)
 X11: make use of the 'extmenu' option:  On to choose among all commands, Off
 	to choose among the traditional extended command subset
+X11: support menu scrolling via (^ < > |) in the extended commands menu
 curses: catch up with tty to not put dolook/whatis autodescribe feedback into
 	^P message recall (multi-digit count feedback was already handled)
 curses: if the interface code ran out of memory, it would crash rather than
@@ -614,7 +615,7 @@ windows-tty: add support for mouse_support:0 (disabled), mouse_support:1
 X11: implement menucolors and allow menus to obey some attributes
 X11: make key translations work with menus on Linux
 X11: allow mouse wheel scrolling to work in menus by default
-X11: handle paged menu control keys
+X11: handle menu scrolling via first-/previous-/next-/last-page keys (^ < > |)
 X11: remember perm_invent window geometry
 X11: handle X errors via panic
 X11: don't reuse perm_invent window for picking an object

win/X11/winmisc.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	winmisc.c	$NHDT-Date: 1554134316 2019/04/01 15:58:36 $  $NHDT-Branch: NetHack-3.6.2-beta01 $:$NHDT-Revision: 1.43 $ */
+/* NetHack 3.6	winmisc.c	$NHDT-Date: 1554135506 2019/04/01 16:18:26 $  $NHDT-Branch: NetHack-3.6.2-beta01 $:$NHDT-Revision: 1.44 $ */
 /* Copyright (c) Dean Luick, 1992                                 */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -1856,11 +1856,12 @@ String *params;
 Cardinal *num_params;
 {
     char ch;
-    int i;
+    int i, pass;
-    int pass;
+    float shown, top;
+    Arg arg[2];
+    Widget hbar, vbar;
     XKeyEvent *xkey = (XKeyEvent *) event;
 
-    nhUse(w);
     nhUse(params);
     nhUse(num_params);
 
@@ -1888,6 +1889,25 @@ Cardinal *num_params;
         exit_x_event = TRUE; /* leave event loop */
         ec_active = FALSE;
         return;
+    } else if (ch == MENU_FIRST_PAGE || ch == MENU_LAST_PAGE) {
+        hbar = vbar = (Widget) 0;
+        find_scrollbars(w, &hbar, &vbar);
+        if (vbar) {
+            top = (ch == MENU_FIRST_PAGE) ? 0.0 : 1.0;
+            XtCallCallbacks(vbar, XtNjumpProc, &top);
+        }
+        return;
+    } else if (ch == MENU_NEXT_PAGE || ch == MENU_PREVIOUS_PAGE) {
+        hbar = vbar = (Widget) 0;
+        find_scrollbars(w, &hbar, &vbar);
+        if (vbar) {
+            XtSetArg(arg[0], nhStr(XtNshown), &shown);
+            XtSetArg(arg[1], nhStr(XtNtopOfThumb), &top);
+            XtGetValues(vbar, arg, TWO);
+            top += ((ch == MENU_NEXT_PAGE) ? shown : -shown);
+            XtCallCallbacks(vbar, XtNjumpProc, &top);
+        }
+        return;
     }
 
     /*