From 79e6ed504729a96cf6e875342976f33baa605377 Mon Sep 17 00:00:00 2001
From: Jonas Maebe <jonas@freepascal.org>
Date: Sun, 14 Jun 2009 14:12:09 +0000
Subject: [PATCH]   * fixed CenterPoint() function (patch by Alexander S.
 Klenin, mantis #13972)

git-svn-id: trunk@13274 -
---
 .gitattributes          |  1 +
 rtl/objpas/types.pp     | 17 ++++++++++++-----
 tests/webtbs/tw13872.pp | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 5 deletions(-)
 create mode 100644 tests/webtbs/tw13872.pp

diff --git a/.gitattributes b/.gitattributes
index 1f10011fea..3a509264fd 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -9157,6 +9157,7 @@ tests/webtbs/tw1376.pp svneol=native#text/plain
 tests/webtbs/tw13763.pp svneol=native#text/plain
 tests/webtbs/tw13813.pp svneol=native#text/plain
 tests/webtbs/tw13820.pp svneol=native#text/plain
+tests/webtbs/tw13872.pp svneol=native#text/plain
 tests/webtbs/tw13890.pp svneol=native#text/plain
 tests/webtbs/tw13948.pp svneol=native#text/plain
 tests/webtbs/tw1398.pp svneol=native#text/plain
diff --git a/rtl/objpas/types.pp b/rtl/objpas/types.pp
index b3bdac65d8..6c4836971a 100644
--- a/rtl/objpas/types.pp
+++ b/rtl/objpas/types.pp
@@ -406,13 +406,20 @@ begin
     OffsetRect:=false;
 end;
 
-function CenterPoint(const Rect: TRect): TPoint;
-
+function Avg(a, b: Longint): Longint;
 begin
-  With Rect do
+  if a < b then
+    Result := a + ((b - a) shr 1)
+  else
+    Result := b + ((a - b) shr 1);
+end;
+
+function CenterPoint(const Rect: TRect): TPoint;
+begin
+  with Rect do
     begin
-    Result.X:=(Left+Right) div 2;
-    Result.Y:=(Top+Bottom) div 2;
+      Result.X := Avg(Left, Right);
+      Result.Y := Avg(Top, Bottom);
     end;
 end;
 
diff --git a/tests/webtbs/tw13872.pp b/tests/webtbs/tw13872.pp
new file mode 100644
index 0000000000..676a8c0bd2
--- /dev/null
+++ b/tests/webtbs/tw13872.pp
@@ -0,0 +1,35 @@
+uses
+  types;
+
+procedure TestAvg(const r: trect);
+var
+  res: tpoint;
+  o1, o2: int64;
+begin
+  res:=centerpoint(r);
+  o1 := (int64(r.left) + r.right) div 2;
+  o2 := (int64(r.top) + r.bottom) div 2;
+  if (res.x <> o1) or
+     (res.y <> o2) then
+    halt(1);
+end;
+
+var
+ r: trect;
+begin
+  r.left := 1;
+  r.right := 3;
+  r.top := 3;
+  r.bottom := 1;
+  testavg(r);
+  r.left:=2000000000;
+  r.right:=2000000002;
+  r.top:=-2000000000;
+  r.bottom:=-2000000002;
+  testavg(r);
+  r.left:=-2000000000;
+  r.right:=2000000002;
+  r.top:=2000000000;
+  r.bottom:=-2000000002;
+end.
+