[PATCH 6/7] gdb/testing/tui: add new functionality to tuiterm.exp

[Andrew Burgess <aburgess@redhat.com>]

While working on the next patch in this series, I was sending
additional commands to the terminal with Term::command.  There was
nothing special about these commands, just normal "print EXPRESSION"
type things, but I clearly poked ncurses in just the right way so that
it started sending two previously unseen control sequences, 'Insert
Line' and 'Delete Characters'.

Now, the Term::command calls I added above were only done to help be
debug the test, without them, these two control sequences are not
triggered.  But, given I've gone to the effort of adding these
features to tuiterm.exp, I figure I might as well share this work.

Additionally, I noticed a bug in 'Erase in Line' that this commit
fixes; in mode 1 the erase should be from the start of the line
through to the cursor, not to the character before the cursor.  This
bug would mean that random characters would sometimes be left in the
terminal output.
---
 gdb/testsuite/lib/tuiterm.exp | 54 ++++++++++++++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 1 deletion(-)

diff --git a/gdb/testsuite/lib/tuiterm.exp b/gdb/testsuite/lib/tuiterm.exp
index 38948015e96..f2be3394db0 100644
--- a/gdb/testsuite/lib/tuiterm.exp
+++ b/gdb/testsuite/lib/tuiterm.exp
@@ -317,13 +317,40 @@ namespace eval Term {
 		# From cursor to end.
 		_clear_in_line $_cur_col $_cols $_cur_row
 	    } elseif {$arg == 1} {
-		_clear_in_line 0 $_cur_col $_cur_row
+		_clear_in_line 0 [expr $_cur_col + 1] $_cur_row
 	    } elseif {$arg == 2} {
 		_clear_in_line 0 $_cols $_cur_row
 	    }
 	}
     }
 
+    # Insert Line
+    #
+    # https://vt100.net/docs/vt510-rm/IL.html
+    proc _csi_L {args} {
+	set arg [_default [lindex $args 0] 1]
+
+	_log_cur "Insert Line ($arg)" {
+	    variable _cur_col
+	    variable _cur_row
+	    variable _rows
+	    variable _cols
+	    variable _chars
+
+	    set y [expr $_rows - 2]
+	    set next_y [expr $y + 1]
+	    while {$y >= $_cur_row} {
+		for {set x 0} {$x < $_cols} {incr x} {
+		    set _chars($x,$next_y) $_chars($x,$y)
+		}
+		incr y -1
+		incr next_y -1
+	    }
+
+	    _clear_lines $_cur_row $_rows
+	}
+    }
+
     # Delete line.
     #
     # https://vt100.net/docs/vt510-rm/DL.html
@@ -349,6 +376,31 @@ namespace eval Term {
 	}
     }
 
+    # Delete Characters
+    #
+    # https://vt100.net/docs/vt510-rm/DCH.html
+    proc _csi_P {args} {
+	set count [_default [lindex $args 0] 1]
+
+	_log_cur "Delete Character ($count)" {
+	    variable _cur_col
+	    variable _cur_row
+	    variable _cols
+	    variable _chars
+
+	    set dx [expr $_cur_col + 1]
+	    set sx [expr $_cur_col + 1 + $count]
+	    set y $_cur_row
+
+	    while {$sx < $_cols} {
+		set _chars($dx,$y) $_chars($sx,$y)
+		incr sx
+		incr dx
+	    }
+	    _clear_in_line $dx $sx $y
+	}
+    }
+
     # Erase chars.
     #
     # https://vt100.net/docs/vt510-rm/ECH.html
-- 
2.25.4