[PATCH 1/5] tui: reset start_line whenever cur_line is reset

[Patrick Palka <patrick@parcs.ath.cx>]

Whenever the command window's cur_line is reset to 0, so should
start_line.  This is because there is an implicit invariant that
0 <= start_line <= cur_line.

gdb/ChangeLog:

	* tui/tui-data.c (tui_clear_win_detail) [CMD_WIN]: Also reset
	start_line.
	(init_win_info) [CMD_WIN]: Ditto.
	* tui/tui-win.c (make_visible_with_new_height) [CMD_WIN]: Ditto.
---
 gdb/tui/tui-data.c | 6 ++++--
 gdb/tui/tui-win.c  | 1 +
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/gdb/tui/tui-data.c b/gdb/tui/tui-data.c
index ed42c8d..e9aa7b3 100644
--- a/gdb/tui/tui-data.c
+++ b/gdb/tui/tui-data.c
@@ -212,8 +212,9 @@ tui_clear_win_detail (struct tui_win_info *win_info)
 	  win_info->detail.source_info.horizontal_offset = 0;
 	  break;
 	case CMD_WIN:
-	  win_info->detail.command_info.cur_line =
-	    win_info->detail.command_info.curch = 0;
+	  win_info->detail.command_info.start_line = 0;
+	  win_info->detail.command_info.cur_line = 0;
+	  win_info->detail.command_info.curch = 0;
 	  break;
 	case DATA_WIN:
 	  win_info->detail.data_display_info.data_content =
@@ -545,6 +546,7 @@ init_win_info (struct tui_win_info *win_info)
       win_info->detail.data_display_info.current_group = 0;
       break;
     case CMD_WIN:
+      win_info->detail.command_info.start_line = 0;
       win_info->detail.command_info.cur_line = 0;
       win_info->detail.command_info.curch = 0;
       break;
diff --git a/gdb/tui/tui-win.c b/gdb/tui/tui-win.c
index feb360b..0150900 100644
--- a/gdb/tui/tui-win.c
+++ b/gdb/tui/tui-win.c
@@ -1510,6 +1510,7 @@ make_visible_with_new_height (struct tui_win_info *win_info)
       tui_display_all_data ();
       break;
     case CMD_WIN:
+      win_info->detail.command_info.start_line = 0;
       win_info->detail.command_info.cur_line = 0;
       win_info->detail.command_info.curch = 0;
 #ifdef HAVE_WRESIZE
-- 
2.5.0.rc0.5.g91e10c5.dirty