From df601267e640ce7eb171f2ce5044915a3cc358b2 Mon Sep 17 00:00:00 2001
From: Iain Patterson <wm@iain.cx>
Date: Fri, 16 Nov 2012 16:00:07 -0800
Subject: [PATCH] Prevent border drifting.

Windows were drifting by FRAME_BORDER_WIDTH pixels when their
borders were toggled on or off.

Windows which had a border before we managed them were drifting
on shutdown and again at startup.  It happened because the absolute
upper-left co-ordinates of a bordered window would in fact be the
upper-left co-ordinates of the border itself, whereas we consider
the client window to have no border and co-ordinates offset by the
titlebar and frame border.
---
 src/client.c |  2 ++
 src/window.c | 27 ++++++++++++++++++++++-----
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/src/client.c b/src/client.c
index 10f25719..89f6277d 100644
--- a/src/client.c
+++ b/src/client.c
@@ -83,6 +83,8 @@ void wClientRestore(WWindow * wwin)
 #endif
 	/* account for titlebar and border */
 	wwin->frame_y += wwin->frame->top_width;
+	wwin->frame_x -= wwin->old_border_width;
+	wwin->frame_y -= wwin->old_border_width;
 	if (HAS_BORDER(wwin)) {
 		wwin->frame_x += FRAME_BORDER_WIDTH;
 		wwin->frame_y += FRAME_BORDER_WIDTH;
diff --git a/src/window.c b/src/window.c
index 7f0a1fee..551cc218 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1178,6 +1178,17 @@ WWindow *wManageWindow(WScreen *scr, Window window)
 		}
 	}
 
+	/* If this is a newly-mapped window which had a border,
+	 * the absolute co-ordinates reported to us are actually
+	 * the co-ordinates of the border.  We, however, track
+	 * the absolute co-ordinates of the client window, offset
+	 * by the title bar and frame border.  As a result
+	 * we need to offset placement of the client by the border
+	 * size so its position matches what we expect.
+	 */
+	x += wwin->old_border_width;
+	y += wwin->old_border_width;
+
 	/*
 	 * wWindowConfigure() will init the client window's size
 	 * (wwin->client.{width,height}) and all other geometry
@@ -2226,7 +2237,9 @@ void wWindowConfigureBorders(WWindow *wwin)
 {
 	if (wwin->frame) {
 		int flags;
-		int newy, oldh;
+		int newx, newy, oldh;
+		int border_width;
+		XWindowAttributes attr;
 
 		flags = WFF_LEFT_BUTTON | WFF_RIGHT_BUTTON;
 
@@ -2244,13 +2257,17 @@ void wWindowConfigureBorders(WWindow *wwin)
 		if (wwin->flags.shaded)
 			flags |= WFF_IS_SHADED;
 
-		oldh = wwin->frame->top_width;
+		if (!XGetWindowAttributes(dpy, wwin->frame->core->window, &attr))
+				attr.border_width = 0;
+		border_width = (flags & WFF_BORDER) ? FRAME_BORDER_WIDTH : 0;
+		oldh = wwin->frame->top_width + attr.border_width;
 		wFrameWindowUpdateBorders(wwin->frame, flags);
-		if (oldh != wwin->frame->top_width) {
-			newy = wwin->frame_y + oldh - wwin->frame->top_width;
+		if (oldh != wwin->frame->top_width + border_width) {
+			newx = wwin->frame_x + attr.border_width - border_width;
+			newy = wwin->frame_y + oldh - border_width - wwin->frame->top_width;
 
 			XMoveWindow(dpy, wwin->client_win, 0, wwin->frame->top_width);
-			wWindowConfigure(wwin, wwin->frame_x, newy, wwin->client.width, wwin->client.height);
+			wWindowConfigure(wwin, newx, newy, wwin->client.width, wwin->client.height);
 		}
 
 		flags = 0;
-- 
2.11.4.GIT