Console: integrate end-of-line hack with cursor positioning.

The previous work for simulating the beyond-right-edge of
screen cursor position is incomplete without integrating this
into the cursor positioning routines. By making the cursor
routines aware of the eat_newline flag, we allow cursor
movements to work correctly with regard to this simulated
position.

* winsup/cygwin/fhandler_console.cc
(fhandler_console::cursor_set): If the X position is beyond
the right edge of the screen, then set the cursor to the
start of the following line, rather than clipping to the
right edge, set the eat_newline flag, indicating that the
the true position is actually one character beyond the
previous line. In all other cases, clear the eat_newline
flag.
(fhandler_console::cursor_rel): Do not apply the delta vector
to the raw Win32 cursor position; call cursor_get and apply
it to the virtual cursor position which takes into account
the eat_newline flag.
(fhandler_console::cursor_get): Take into account the
eat_newline flag. If it is set, then report an adjusted
position that is one column beyond the end of the previous
line.

1 files changed, 23 insertions, 8 deletions

diff --git a/winsup/cygwin/fhandler_console.cc b/winsup/cygwin/fhandler_console.cc
index 0d3d234d9..5fe448051 100644
--- a/winsup/cygwin/fhandler_console.cc
+++ b/winsup/cygwin/fhandler_console.cc
@@ -1311,8 +1311,14 @@ fhandler_console::cursor_set (bool rel_to_top, int x, int y)
   else if (rel_to_top)
     y += con.b.srWindow.Top;
 
-  if (x > con.dwWinSize.X)
-    x = con.dwWinSize.X - 1;
+  con.eat_newline = false;
+
+  if (x >= con.dwWinSize.X)
+    {
+      y++;
+      x = 0;
+      con.eat_newline = true;
+    }
   else if (x < 0)
     x = 0;
 
@@ -1322,11 +1328,12 @@ fhandler_console::cursor_set (bool rel_to_top, int x, int y)
 }
 
 void __reg3
-fhandler_console::cursor_rel (int x, int y)
+fhandler_console::cursor_rel (int xdelta, int ydelta)
 {
-  con.fillin (get_output_handle ());
-  x += con.b.dwCursorPosition.X;
-  y += con.b.dwCursorPosition.Y;
+  int x, y;
+  cursor_get(&x, &y);
+  x += xdelta;
+  y += ydelta;
   cursor_set (false, x, y);
 }
 
@@ -1334,8 +1341,16 @@ void __reg3
 fhandler_console::cursor_get (int *x, int *y)
 {
   con.fillin (get_output_handle ());
-  *y = con.b.dwCursorPosition.Y;
-  *x = con.b.dwCursorPosition.X;
+  if (!con.eat_newline)
+    {
+      *y = con.b.dwCursorPosition.Y;
+      *x = con.b.dwCursorPosition.X;
+    }
+  else
+    {
+      *y = con.b.dwCursorPosition.Y - 1;
+      *x = con.dwWinSize.X;
+    }
 }
 
 /* VT100 line drawing graphics mode maps `abcdefghijklmnopqrstuvwxyz{|}~ to