[gdb/testsuite] Fix Cursor Horizontal Absolute clipping

I looked at the tuiterm implementation of Cursor Horizontal Absolute:
...
    proc _csi_G {args} {
	set arg [_default [lindex $args 0] 1]

	_log_cur "Cursor Horizontal Absolute ($arg)" {
	    variable _cur_col
	    variable _cols

	    set _cur_col [expr {min ($arg - 1, $_cols)}]
	}
    }
...
and noticed a problem with the clipping behavior.

If we have say $_cols == 80, and we do _csi_G 81 we get $_cur_col == 80, while
$_cur_col is zero-based and should be in the 0..79 range.

Fix this by using:
...
	    set _cur_col [expr {min ($arg, $_cols)} - 1]
...
which gets us $_cur_col == 79.

Add two boundary tests to gdb.tui/tuiterm.exp.

Tested on x86_64-linux.

Approved-By: Tom Tromey <tom@tromey.com>

2 files changed, 17 insertions, 1 deletions

diff --git a/gdb/testsuite/gdb.tui/tuiterm.exp b/gdb/testsuite/gdb.tui/tuiterm.exp
index 9dc2402..fff7c37 100644
--- a/gdb/testsuite/gdb.tui/tuiterm.exp
+++ b/gdb/testsuite/gdb.tui/tuiterm.exp
@@ -435,6 +435,22 @@ proc test_horizontal_absolute { } {
 	"qrstuvwx"
 	"yz01234 "
     } 3 2
+
+    Term::_csi_G 8
+    check "cursor horizontal absolute 3" {
+	"abcdefgh"
+	"ijklmnop"
+	"qrstuvwx"
+	"yz01234 "
+    } 7 2
+
+    Term::_csi_G 9
+    check "cursor horizontal absolute 4" {
+	"abcdefgh"
+	"ijklmnop"
+	"qrstuvwx"
+	"yz01234 "
+    } 7 2
 }
 
 proc test_cursor_position { } {
diff --git a/gdb/testsuite/lib/tuiterm.exp b/gdb/testsuite/lib/tuiterm.exp
index a0cd199..71ef6a4 100644
--- a/gdb/testsuite/lib/tuiterm.exp
+++ b/gdb/testsuite/lib/tuiterm.exp
@@ -251,7 +251,7 @@ namespace eval Term {
 	    variable _cur_col
 	    variable _cols
 
-	    set _cur_col [expr {min ($arg - 1, $_cols)}]
+	    set _cur_col [expr {min ($arg, $_cols)} - 1]
 	}
     }