[1601205] */' now work to jump to stashes in the level-map. ; retains its old

behaviour of travel-to-cursor, which may disconcert folks used to its behaviour
when targeting, but I suspect they'll get used to it.

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@488 c06c8d41-db1a-0410-9941-cceddc491573

1 files changed, 368 insertions, 371 deletions

diff --git a/crawl-ref/source/view.cc b/crawl-ref/source/view.cc
index 11aea1a7a0..8cc87ab02b 100644
--- a/crawl-ref/source/view.cc
+++ b/crawl-ref/source/view.cc
@@ -1875,8 +1875,10 @@ void find_features(const std::vector<coord_def>& features,
 static int find_feature( const std::vector<coord_def>& features,
                          unsigned char feature, int curs_x, int curs_y, 
                          int start_x, int start_y, 
-                         int ignore_count, char *move_x, char *move_y) {
-    int firstx = -1, firsty = -1;
+                         int ignore_count, 
+                         char *move_x, char *move_y,
+                         bool forward) {
+    int firstx = -1, firsty = -1, firstmatch = -1;
     int matchcount = 0;
 
     for (unsigned feat = 0; feat < features.size(); ++feat) {
@@ -1884,15 +1886,16 @@ static int find_feature( const std::vector<coord_def>& features,
 
         if (is_feature(feature, coord.x, coord.y)) {
             ++matchcount;
-            if (!ignore_count--) {
+            if (forward? !ignore_count-- : --ignore_count == 1) {
                 // We want to cursor to (x,y)
                 *move_x = coord.x - (start_x + curs_x);
                 *move_y = coord.y - (start_y + curs_y);
                 return matchcount;
             }
-            else if (firstx == -1) {
+            else if (!forward || firstx == -1) {
                 firstx = coord.x;
                 firsty = coord.y;
+                firstmatch = matchcount;
             }
         }
     }
@@ -1901,7 +1904,7 @@ static int find_feature( const std::vector<coord_def>& features,
     if (firstx != -1) {
         *move_x = firstx - (start_x + curs_x);
         *move_y = firsty - (start_y + curs_y);
-        return 1;
+        return matchcount;
     }
     return 0;
 }
@@ -1929,6 +1932,105 @@ static int cset_adjust(int raw)
 }
 #endif
 
+static void draw_level_map(
+        int start_x, int start_y, int screen_y, bool travel_mode)
+{
+    int bufcount2 = 0;
+    screen_buffer_t buffer2[GYM * GXM * 2];        
+    const int num_lines = get_number_of_lines();
+
+    _setcursortype(_NOCURSOR);
+
+#ifdef PLAIN_TERM
+    gotoxy(1, 1);
+#endif
+
+    for (int j = 0; j < num_lines; j++)
+    {
+        for (int i = 0; i < 80; i++)
+        {
+            screen_buffer_t colour = DARKGREY;
+            if (start_y + j >= 65 || start_y + j <= 3 
+                || start_x + i < 0 || start_x + i >= GXM - 1)
+            {
+                buffer2[bufcount2 + 1] = DARKGREY;
+                buffer2[bufcount2] = 0;
+                bufcount2 += 2;
+
+#ifdef PLAIN_TERM
+                goto print_it;
+#endif
+
+#ifdef DOS_TERM
+                continue;
+#endif
+            }
+
+            colour = colour_code_map(start_x + i, start_y + j,
+                            Options.item_colour, 
+                            travel_mode && Options.travel_colour);
+
+            buffer2[bufcount2 + 1] = colour;
+            buffer2[bufcount2] = 
+                        (unsigned char) env.map[start_x + i][start_y + j];
+            
+            if (start_x + i + 1 == you.x_pos && start_y + j + 1 == you.y_pos)
+            {
+                // [dshaligram] Draw the @ symbol on the level-map. It's no
+                // longer saved into the env.map, so we need to draw it 
+                // directly.
+                buffer2[bufcount2 + 1] = WHITE;
+                buffer2[bufcount2]     = you.symbol;
+            }
+
+            // If we've a waypoint on the current square, *and* the square is
+            // a normal floor square with nothing on it, show the waypoint
+            // number.
+            if (Options.show_waypoints)
+            {
+                // XXX: This is a horrible hack.
+                screen_buffer_t &bc = buffer2[bufcount2];
+                int gridx = start_x + i + 1, gridy = start_y + j + 1;
+                unsigned char ch = is_waypoint(gridx, gridy);
+                if (ch && (bc == get_sightmap_char(DNGN_FLOOR) ||
+                           bc == get_magicmap_char(DNGN_FLOOR)))
+                    bc = ch;
+            }
+            
+            bufcount2 += 2;
+
+#ifdef PLAIN_TERM
+
+          print_it:
+            // avoid line wrap
+            if (i == 79)
+                continue;
+
+            // newline
+            if (i == 0 && j > 0)
+                gotoxy( 1, j + 1 );
+
+            int ch = buffer2[bufcount2 - 2];
+#ifdef USE_CURSES
+            ch = cset_adjust( ch );
+#endif
+            textcolor( buffer2[bufcount2 - 1] );
+            putch(ch);
+#endif
+        }
+    }
+
+#ifdef USE_CURSES
+    set_altcharset(false);
+#endif
+
+#ifdef DOS_TERM
+    puttext(1, 1, 80, 25, buffer2);
+#endif
+
+    _setcursortype(_NORMALCURSOR);
+}
+
 // show_map() now centers the known map along x or y.  This prevents
 // the player from getting "artificial" location clues by using the
 // map to see how close to the end they are.  They'll need to explore
@@ -1937,8 +2039,6 @@ void show_map( FixedVector<int, 2> &spec_place, bool travel_mode )
 {
     int i, j;
 
-    int bufcount2 = 0;
-
     char move_x = 0;
     char move_y = 0;
     char getty = 0;
@@ -1958,9 +2058,6 @@ void show_map( FixedVector<int, 2> &spec_place, bool travel_mode )
         arrange_features(features);
     }
 
-    // buffer2[GYM * GXM * 2] segfaults my box {dlb}
-    screen_buffer_t buffer2[GYM * GXM * 2];        
-
     char min_x = 80, max_x = 0, min_y = 0, max_y = 0;
     bool found_y = false;
 
@@ -1994,7 +2091,7 @@ void show_map( FixedVector<int, 2> &spec_place, bool travel_mode )
 
     const int start_x = min_x + (max_x - min_x + 1) / 2 - 40; // no x scrolling
     const int block_step = Options.level_map_cursor_step;
-    int start_y;                                              // y does scroll
+    int start_y = 0;                                          // y does scroll
 
     int screen_y = you.y_pos;
 
@@ -2017,6 +2114,9 @@ void show_map( FixedVector<int, 2> &spec_place, bool travel_mode )
     int curs_y = you.y_pos - screen_y + half_screen;
     int search_feat = 0, search_found = 0, anchor_x = -1, anchor_y = -1;
 
+    bool map_alive  = true;
+    bool redraw_map = true;
+
 #ifdef DOS_TERM
     gettext(1, 1, 80, 25, buffer);
     window(1, 1, 80, 25);
@@ -2025,415 +2125,312 @@ void show_map( FixedVector<int, 2> &spec_place, bool travel_mode )
     clrscr();
     textcolor(DARKGREY);
 
-  put_screen:
-    bufcount2 = 0;
+    while (map_alive)
+    {
+        start_y = screen_y - half_screen;
 
-    _setcursortype(_NOCURSOR);
+        if (redraw_map)
+            draw_level_map(start_x, start_y, screen_y, travel_mode);
 
-#ifdef PLAIN_TERM
-    gotoxy(1, 1);
-#endif
-
-    start_y = screen_y - half_screen;
+        redraw_map = true;
+        gotoxy(curs_x, curs_y);
 
-    for (j = 0; j < num_lines; j++)
-    {
-        for (i = 0; i < 80; i++)
+        getty = getchm(KC_LEVELMAP);
+        if (getty == 0)
         {
-            screen_buffer_t colour = DARKGREY;
-            if (start_y + j >= 65 || start_y + j <= 3 
-                || start_x + i < 0 || start_x + i >= GXM - 1)
-            {
-                buffer2[bufcount2 + 1] = DARKGREY;
-                buffer2[bufcount2] = 0;
-                bufcount2 += 2;
-
-#ifdef PLAIN_TERM
-                goto print_it;
-#endif
+            getty = getchm(KC_LEVELMAP);
+            // [dshaligram] DOS madness.
+            getty = dos_direction_unmunge(getty);
+        }
 
-#ifdef DOS_TERM
-                continue;
+#if defined(WIN32CONSOLE) || defined(DOS)
+        // Translate shifted numpad to shifted vi keys. Yes,
+        // this is horribly hacky.
+        {
+            static int win_keypad[] = { 'B', 'J', 'N', 
+                                        'H', '5', 'L',
+                                        'Y', 'K', 'U' };
+            if (getty >= '1' && getty <= '9')
+                getty = win_keypad[ getty - '1' ];
+        }
 #endif
 
-            }
+        switch (getty)
+        {
+        case '?':
+            show_levelmap_help();
+            break;
 
-            colour = colour_code_map(start_x + i, start_y + j,
-                            Options.item_colour, 
-                            travel_mode && Options.travel_colour);
+        case CONTROL('C'):
+            clear_map();
+            break;
 
-            buffer2[bufcount2 + 1] = colour;
-            buffer2[bufcount2] = 
-                        (unsigned char) env.map[start_x + i][start_y + j];
-            
-            if (start_x + i + 1 == you.x_pos && start_y + j + 1 == you.y_pos)
+        case CONTROL('F'):
+        case CONTROL('W'):
+            travel_cache.add_waypoint(start_x + curs_x, start_y + curs_y);
+            // We need to do this all over again so that the user can jump
+            // to the waypoint he just created.
+            features.clear();
+            find_travel_pos(you.x_pos, you.y_pos, NULL, NULL, &features);
+            // Sort features into the order the player is likely to prefer.
+            arrange_features(features);
+            move_x = move_y = 0;
+            break;
+        case CONTROL('E'):
+        case CONTROL('X'):
             {
-                // [dshaligram] Draw the @ symbol on the level-map. It's no
-                // longer saved into the env.map, so we need to draw it 
-                // directly.
-                buffer2[bufcount2 + 1] = WHITE;
-                buffer2[bufcount2]     = you.symbol;
-            }
+                int x = start_x + curs_x, y = start_y + curs_y;
+                if (getty == CONTROL('X'))
+                    toggle_exclude(x, y);
+                else
+                    clear_excludes();
 
-            // If we've a waypoint on the current square, *and* the square is
-            // a normal floor square with nothing on it, show the waypoint
-            // number.
-            if (Options.show_waypoints)
-            {
-                // XXX: This is a horrible hack.
-                screen_buffer_t &bc = buffer2[bufcount2];
-                int gridx = start_x + i + 1, gridy = start_y + j + 1;
-                unsigned char ch = is_waypoint(gridx, gridy);
-                if (ch && (bc == get_sightmap_char(DNGN_FLOOR) ||
-                           bc == get_magicmap_char(DNGN_FLOOR)))
-                    bc = ch;
+                // We now need to redo travel colours
+                features.clear();
+                find_travel_pos(you.x_pos, you.y_pos, NULL, NULL, &features);
+                // Sort features into the order the player is likely to prefer.
+                arrange_features(features);
+
+                move_x = move_y = 0;
             }
+            break;
             
-            bufcount2 += 2;
+        case 'b':
+        case '1':
+            move_x = -1;
+            move_y = 1;
+            break;
 
-#ifdef PLAIN_TERM
+        case 'j':
+        case '2':
+            move_y = 1;
+            move_x = 0;
+            break;
 
-          print_it:
-            // avoid line wrap
-            if (i == 79)
-                continue;
+        case 'u':
+        case '9':
+            move_x = 1;
+            move_y = -1;
+            break;
 
-            // newline
-            if (i == 0 && j > 0)
-                gotoxy( 1, j + 1 );
+        case 'k':
+        case '8':
+            move_y = -1;
+            move_x = 0;
+            break;
 
-            int ch = buffer2[bufcount2 - 2];
-#ifdef USE_CURSES
-            ch = cset_adjust( ch );
-#endif
-            textcolor( buffer2[bufcount2 - 1] );
-            putch(ch);
-#endif
-        }
-    }
+        case 'y':
+        case '7':
+            move_y = -1;
+            move_x = -1;
+            break;
 
-#ifdef USE_CURSES
-    set_altcharset(false);
-#endif
+        case 'h':
+        case '4':
+            move_x = -1;
+            move_y = 0;
+            break;
 
-#ifdef DOS_TERM
-    puttext(1, 1, 80, 25, buffer2);
-#endif
+        case 'n':
+        case '3':
+            move_y = 1;
+            move_x = 1;
+            break;
 
-    _setcursortype(_NORMALCURSOR);
-    gotoxy(curs_x, curs_y);
-
-  gettything:
-    getty = getchm(KC_LEVELMAP);
-
-    if (travel_mode && getty != 0 && getty != '+' && getty != '-'
-        && getty != 'h' && getty != 'j' && getty != 'k' && getty != 'l'
-        && getty != 'y' && getty != 'u' && getty != 'b' && getty != 'n'
-        && getty != 'H' && getty != 'J' && getty != 'K' && getty != 'L'
-        && getty != 'Y' && getty != 'U' && getty != 'B' && getty != 'N'
-        // Keystrokes to initiate travel
-        && getty != ',' && getty != '.' && getty != '\r' && getty != ';'
-
-        // Keystrokes for jumping to features
-        && getty != '<' && getty != '>' && getty != '@' && getty != '\t'
-        && getty != '^' && getty != '_'
-        && (getty < '0' || getty > '9')
-        && getty != CONTROL('X')
-        && getty != CONTROL('E')
-        && getty != CONTROL('F')
-        && getty != CONTROL('W')
-        && getty != CONTROL('C')
-        && getty != '?'
-        && getty != 'X' && getty != 'F' && getty != 'I' && getty != 'W')
-    {
-        goto putty;
-    }
+        case 'l':
+        case '6':
+            move_x = 1;
+            move_y = 0;
+            break;
 
-    if (!travel_mode && getty != 0 && getty != '+' && getty != '-'
-        && getty != 'h' && getty != 'j' && getty != 'k' && getty != 'l'
-        && getty != 'y' && getty != 'u' && getty != 'b' && getty != 'n'
-        && getty != 'H' && getty != 'J' && getty != 'K' && getty != 'L'
-        && getty != 'Y' && getty != 'U' && getty != 'B' && getty != 'N'
-        && getty != '.' && getty != 'S' && (getty < '0' || getty > '9')
-        // Keystrokes for jumping to features
-        && getty != '<' && getty != '>' && getty != '@' && getty != '\t'
-        && getty != '^' && getty != '_')
-    {
-        goto gettything;
-    }
+        case 'B':
+            move_x = -block_step;
+            move_y = block_step;
+            break;
 
-    if (getty == 0)
-    {
-        getty = getchm(KC_LEVELMAP);
-        // [dshaligram] DOS madness.
-        getty = dos_direction_unmunge(getty);
-    }
+        case 'J':
+            move_y = block_step;
+            move_x = 0;
+            break;
 
-#if defined(WIN32CONSOLE) || defined(DOS)
-    // Translate shifted numpad to shifted vi keys. Yes,
-    // this is horribly hacky.
-    {
-        static int win_keypad[] = { 'B', 'J', 'N', 
-                                    'H', '5', 'L',
-                                    'Y', 'K', 'U' };
-        if (getty >= '1' && getty <= '9')
-            getty = win_keypad[ getty - '1' ];
-    }
-#endif
+        case 'U':
+            move_x = block_step;
+            move_y = -block_step;
+            break;
 
-    switch (getty)
-    {
-    case '?':
-        show_levelmap_help();
-        break;
-
-    case CONTROL('C'):
-        clear_map();
-        break;
-
-    case CONTROL('F'):
-    case CONTROL('W'):
-        travel_cache.add_waypoint(start_x + curs_x, start_y + curs_y);
-        // We need to do this all over again so that the user can jump
-        // to the waypoint he just created.
-        features.clear();
-        find_travel_pos(you.x_pos, you.y_pos, NULL, NULL, &features);
-        // Sort features into the order the player is likely to prefer.
-        arrange_features(features);
-        move_x = move_y = 0;
-        break;
-    case CONTROL('E'):
-    case CONTROL('X'):
+        case 'K':
+            move_y = -block_step;
+            move_x = 0;
+            break;
+
+        case 'Y':
+            move_y = -block_step;
+            move_x = -block_step;
+            break;
+
+        case 'H':
+            move_x = -block_step;
+            move_y = 0;
+            break;
+
+        case 'N':
+            move_y = block_step;
+            move_x = block_step;
+            break;
+
+        case 'L':
+            move_x = block_step;
+            move_y = 0;
+            break;
+
+        case '+':
+            move_y = 20;
+            move_x = 0;
+            break;
+        case '-':
+            move_y = -20;
+            move_x = 0;
+            break;
+        case '<':
+        case '>':
+        case '@':
+        case '\t':
+        case '^':
+        case '_':
+        case 'X':
+        case 'F':
+        case 'W':
+        case 'I':
+        case '*':
+        case '/':
+        case '\'':
         {
-            int x = start_x + curs_x, y = start_y + curs_y;
-            if (getty == CONTROL('X'))
-                toggle_exclude(x, y);
-            else
-                clear_excludes();
+            bool forward = true;
 
-            // We now need to redo travel colours
-            features.clear();
-            find_travel_pos(you.x_pos, you.y_pos, NULL, NULL, &features);
-            // Sort features into the order the player is likely to prefer.
-            arrange_features(features);
+            if (getty == '/' || getty == ';')
+                forward = false;
 
-            move_x = move_y = 0;
-        }
-        break;
-        
-    case 'b':
-    case '1':
-        move_x = -1;
-        move_y = 1;
-        break;
-
-    case 'j':
-    case '2':
-        move_y = 1;
-        move_x = 0;
-        break;
-
-    case 'u':
-    case '9':
-        move_x = 1;
-        move_y = -1;
-        break;
-
-    case 'k':
-    case '8':
-        move_y = -1;
-        move_x = 0;
-        break;
-
-    case 'y':
-    case '7':
-        move_y = -1;
-        move_x = -1;
-        break;
-
-    case 'h':
-    case '4':
-        move_x = -1;
-        move_y = 0;
-        break;
-
-    case 'n':
-    case '3':
-        move_y = 1;
-        move_x = 1;
-        break;
-
-    case 'l':
-    case '6':
-        move_x = 1;
-        move_y = 0;
-        break;
-
-    case 'B':
-        move_x = -block_step;
-        move_y = block_step;
-        break;
-
-    case 'J':
-        move_y = block_step;
-        move_x = 0;
-        break;
-
-    case 'U':
-        move_x = block_step;
-        move_y = -block_step;
-        break;
-
-    case 'K':
-        move_y = -block_step;
-        move_x = 0;
-        break;
-
-    case 'Y':
-        move_y = -block_step;
-        move_x = -block_step;
-        break;
-
-    case 'H':
-        move_x = -block_step;
-        move_y = 0;
-        break;
-
-    case 'N':
-        move_y = block_step;
-        move_x = block_step;
-        break;
-
-    case 'L':
-        move_x = block_step;
-        move_y = 0;
-        break;
-
-    case '+':
-        move_y = 20;
-        move_x = 0;
-        break;
-    case '-':
-        move_y = -20;
-        move_x = 0;
-        break;
-    case '<':
-    case '>':
-    case '@':
-    case '\t':
-    case '^':
-    case '_':
-    case 'X':
-    case 'F':
-    case 'W':
-    case 'I':
-        move_x = 0;
-        move_y = 0;
-        if (anchor_x == -1) {
-            anchor_x = start_x + curs_x - 1;
-            anchor_y = start_y + curs_y - 1;
-        }
-        if (search_feat != getty) {
-            search_feat         = getty;
-            search_found        = 0;
+            if (getty == '/' || getty == ';' || getty == ';' || getty == '\'')
+                getty = 'I';
+
+            move_x = 0;
+            move_y = 0;
+            if (anchor_x == -1) {
+                anchor_x = start_x + curs_x - 1;
+                anchor_y = start_y + curs_y - 1;
+            }
+            if (search_feat != getty) {
+                search_feat         = getty;
+                search_found        = 0;
+            }
+            if (travel_mode)
+                search_found = find_feature(features, getty, curs_x, curs_y, 
+                                            start_x, start_y,
+                                            search_found, 
+                                            &move_x, &move_y,
+                                            forward);
+            else
+                search_found = find_feature(getty, curs_x, curs_y,
+                                            start_x, start_y,
+                                            anchor_x, anchor_y,
+                                            search_found, &move_x, &move_y);
+            break;
         }
-        if (travel_mode)
-            search_found = find_feature(features, getty, curs_x, curs_y, 
-                                        start_x, start_y,
-                                        search_found, &move_x, &move_y);
-        else
-            search_found = find_feature(getty, curs_x, curs_y,
-                                        start_x, start_y,
-                                        anchor_x, anchor_y,
-                                        search_found, &move_x, &move_y);
-        break;
-    case '.':
-    case '\r':
-    case 'S':
-    case ',':
-    case ';':
-    {
-        int x = start_x + curs_x, y = start_y + curs_y;
-        if (travel_mode && x == you.x_pos && y == you.y_pos)
+        case '.':
+        case '\r':
+        case 'S':
+        case ',':
+        case ';':
         {
-            if (you.travel_x > 0 && you.travel_y > 0) {
-                move_x = you.travel_x - x;
-                move_y = you.travel_y - y;
+            int x = start_x + curs_x, y = start_y + curs_y;
+            if (travel_mode && x == you.x_pos && y == you.y_pos)
+            {
+                if (you.travel_x > 0 && you.travel_y > 0) {
+                    move_x = you.travel_x - x;
+                    move_y = you.travel_y - y;
+                }
+                break;
+            }
+            else {
+                spec_place[0] = x;
+                spec_place[1] = y;
+                map_alive = false;
+                break;
             }
-            break;
         }
-        else {
-            spec_place[0] = x;
-            spec_place[1] = y;
-            goto putty;
+        default:
+            move_x = 0;
+            move_y = 0;
+            if (travel_mode)
+            {
+                map_alive = false;
+                break;
+            }
+            redraw_map = false;
+            continue;
         }
-    }
-    default:
-        move_x = 0;
-        move_y = 0;
-        break;
-    }
 
-    if (curs_x + move_x < 1 || curs_x + move_x > 80)
-        move_x = 0;
+        if (!map_alive)
+            break;
+
+        if (curs_x + move_x < 1 || curs_x + move_x > 80)
+            move_x = 0;
 
-    curs_x += move_x;
+        curs_x += move_x;
 
-    if (num_lines < map_lines)
-    {
-        // Scrolling only happens when we don't have a large enough 
-        // display to show the known map.
-        if (getty == '-' || getty == '+')
+        if (num_lines < map_lines)
         {
-            if (getty == '-')
-                screen_y -= 20;
+            // Scrolling only happens when we don't have a large enough 
+            // display to show the known map.
+            if (getty == '-' || getty == '+')
+            {
+                if (getty == '-')
+                    screen_y -= 20;
 
-            if (screen_y <= min_y + half_screen)
-                screen_y = min_y + half_screen;
+                if (screen_y <= min_y + half_screen)
+                    screen_y = min_y + half_screen;
 
-            if (getty == '+')
-                screen_y += 20;
+                if (getty == '+')
+                    screen_y += 20;
 
-            if (screen_y >= max_y - half_screen)
-                screen_y = max_y - half_screen;
+                if (screen_y >= max_y - half_screen)
+                    screen_y = max_y - half_screen;
 
-            goto put_screen;
-        }
+                continue;
+            }
 
-        if (curs_y + move_y < 1)
-        {
-            // screen_y += (curs_y + move_y) - 1;
-            screen_y += move_y;
+            if (curs_y + move_y < 1)
+            {
+                // screen_y += (curs_y + move_y) - 1;
+                screen_y += move_y;
 
-            if (screen_y < min_y + half_screen) {
-                move_y   = screen_y - (min_y + half_screen);
-                screen_y = min_y + half_screen;
+                if (screen_y < min_y + half_screen) {
+                    move_y   = screen_y - (min_y + half_screen);
+                    screen_y = min_y + half_screen;
+                }
+                else
+                    move_y = 0;
             }
-            else
-                move_y = 0;
-        }
 
-        if (curs_y + move_y > num_lines - 1)
-        {
-            // screen_y += (curs_y + move_y) - num_lines + 1;
-            screen_y += move_y;
+            if (curs_y + move_y > num_lines - 1)
+            {
+                // screen_y += (curs_y + move_y) - num_lines + 1;
+                screen_y += move_y;
 
-            if (screen_y > max_y - half_screen) {
-                move_y   = screen_y - (max_y - half_screen);
-                screen_y = max_y - half_screen;
+                if (screen_y > max_y - half_screen) {
+                    move_y   = screen_y - (max_y - half_screen);
+                    screen_y = max_y - half_screen;
+                }
+                else
+                    move_y = 0;
             }
-            else
-                move_y = 0;
         }
-    }
 
-    if (curs_y + move_y < 1 || curs_y + move_y > num_lines)
-        move_y = 0;
+        if (curs_y + move_y < 1 || curs_y + move_y > num_lines)
+            move_y = 0;
 
-    curs_y += move_y;
-    goto put_screen;
-
-  putty:
+        curs_y += move_y;
+    }
 
 #ifdef DOS_TERM
     puttext(1, 1, 80, 25, buffer);