From 40f3dc0db7243f04517f65af78428414cae51480 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ian@liberator.relativity.greenend.org.uk>
Date: Wed, 21 Oct 2009 23:46:03 +0100
Subject: [PATCH] check for unexpected mouse pointer motion

---
 yarrg/pages.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/yarrg/pages.c b/yarrg/pages.c
index ff2672d..28364a0 100644
--- a/yarrg/pages.c
+++ b/yarrg/pages.c
@@ -154,6 +154,28 @@ static void check_not_disturbed(void) {
   }
 }      
 
+static void check_pointer_not_disturbed(void) {
+  Window got_root, got_child;
+  int got_root_x, got_root_y;
+  int got_win_x, got_win_y;
+  unsigned got_mask;
+
+  int r= XQueryPointer(disp,id, &got_root,&got_child,
+		       &got_root_x, &got_root_y,
+		       &got_win_x, &got_win_y,
+		       &got_mask);
+  if (!r ||
+      got_win_x!=commod_page_point.x ||
+      got_win_y!=commod_page_point.y) {
+    progress("");
+    fprintf(stderr,"\nunexpected mouse position:"
+	    " samescreen=%d got=%dx%d want=%dx%d",
+	    r, got_win_x,got_win_y,
+	    commod_page_point.x,commod_page_point.y);
+    fatal("Mouse pointer moved.");
+  }
+}
+
 static void send_key(KeySym sym) {
   check_not_disturbed();
   XTestFakeKeyEvent(disp, keycode(sym),1, 0);
@@ -174,6 +196,7 @@ static void send_mouse_1_updown(int x, int y) {
 }
 static void pgdown_by_mouse(void) {
   check_not_disturbed();
+  check_pointer_not_disturbed();
   debugf("PAGING   Mouse\n");
   send_mouse_1_updown_here();
   sync_after_input();
-- 
2.30.2