From 4f0b1262c555c05ab6c51bcd70164be0d2df6a3e Mon Sep 17 00:00:00 2001
From: PatR <rankin@nethack.org>
Date: Tue, 25 Jun 2019 03:17:47 -0700
Subject: [PATCH] curses clipped map 'scrollbars'

The position bars shown by curses when the map is clipped weren't
being drawn as intended (integer arithmetic).  Changing parentheses
was enough to get it working, but it didn't handle the edge case
where non-zero got rounded to 0 (so when map was panned down, the
uppermost character of the vertical position bar still showed '*',
falsely indicating that top of map was currently within view.
---
 doc/fixes36.3         |  7 ++++++-
 win/curses/curswins.c | 22 ++++++++++++++++------
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/doc/fixes36.3 b/doc/fixes36.3
index a96d543d0..8d778b1c9 100644
--- a/doc/fixes36.3
+++ b/doc/fixes36.3
@@ -1,4 +1,4 @@
-$NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.70 $ $NHDT-Date: 1561455021 2019/06/25 09:30:21 $
+$NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.71 $ $NHDT-Date: 1561457861 2019/06/25 10:17:41 $
 
 This fixes36.3 file is here to capture information about updates in the 3.6.x
 lineage following the release of 3.6.2 in May 2019. Please note, however,
@@ -151,6 +151,11 @@ curses: make text windows wider so that help feedback is more readable
 curses: using ':' for search string matching to toggle menu items in a multple
 	page menu would highlight arbitrary items on the currently visible
 	page in sync with the lines that matching items had on other pages
+curses: when map window was clipped, the 'scrollbars' shown to indicate which
+	part of the map was in view didn't work as intended, always drawing
+	"*--------------" for horizontal (and comparable '*' with multiple '|'
+	underneath for vertical) when it meant to show "---******------" if
+	the 2nd and 3rd fifths (for example) were currently within view
 curses+'perm_invent': entries were wrapping without any control; usually not
 	noticeable because next entry overwrote, but visible for final entry
 	when whole inventory fit within the available height; looked ok with
diff --git a/win/curses/curswins.c b/win/curses/curswins.c
index 9599b4de8..006589510 100644
--- a/win/curses/curswins.c
+++ b/win/curses/curswins.c
@@ -624,9 +624,14 @@ curses_draw_map(int sx, int sy, int ex, int ey)
     vsb_bar.attr = A_NORMAL;
 
     /* Horizontal scrollbar */
-    if ((sx > 0) || (ex < (COLNO - 1))) {
-        sbsx = (sx * ((long) (ex - sx + 1) / COLNO));
-        sbex = (ex * ((long) (ex - sx + 1) / COLNO));
+    if (sx > 0 || ex < (COLNO - 1)) {
+         sbsx = (int) (((long) sx * (long) (ex - sx + 1)) / (long) COLNO);
+         sbex = (int) (((long) ex * (long) (ex - sx + 1)) / (long) COLNO);
+
+        if (sx > 0 && sbsx == 0)
+            ++sbsx;
+        if (ex < ROWNO - 1 && sbex == ROWNO - 1)
+            --sbex;
 
         for (count = 0; count < sbsx; count++) {
             write_char(mapwin, count + bspace, ey - sy + 1 + bspace, hsb_back);
@@ -642,9 +647,14 @@ curses_draw_map(int sx, int sy, int ex, int ey)
     }
 
     /* Vertical scrollbar */
-    if ((sy > 0) || (ey < (ROWNO - 1))) {
-        sbsy = (sy * ((long) (ey - sy + 1) / ROWNO));
-        sbey = (ey * ((long) (ey - sy + 1) / ROWNO));
+    if (sy > 0 || ey < (ROWNO - 1)) {
+        sbsy = (int) (((long) sy * (long) (ey - sy + 1)) / (long) ROWNO);
+        sbey = (int) (((long) ey * (long) (ey - sy + 1)) / (long) ROWNO);
+
+        if (sy > 0 && sbsy == 0)
+            ++sbsy;
+        if (ey < ROWNO - 1 && sbey == ROWNO - 1)
+            --sbey;
 
         for (count = 0; count < sbsy; count++) {
             write_char(mapwin, ex - sx + 1 + bspace, count + bspace, vsb_back);