From da5f9a56703b405d9f37231104d3f33d4a89029d Mon Sep 17 00:00:00 2001
From: zeljko <zeljko@lazarus-ide.org>
Date: Sat, 9 Jul 2011 17:26:23 +0000
Subject: [PATCH] Qt: fixed few memleaks in Qt library with our handling of
 QRegion. Each reference created by QPainter_clipRegion() must be
 destroyed.Small optimization in TQtWidgetSet.IntersectClipRect.

git-svn-id: trunk@31622 -
---
 lcl/interfaces/qt/qtobjects.pas |  9 +++++--
 lcl/interfaces/qt/qtwinapi.inc  | 45 ++++++++++++++++++++++-----------
 2 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/lcl/interfaces/qt/qtobjects.pas b/lcl/interfaces/qt/qtobjects.pas
index 9c6d4779b2..ff7bf8a128 100644
--- a/lcl/interfaces/qt/qtobjects.pas
+++ b/lcl/interfaces/qt/qtobjects.pas
@@ -2977,9 +2977,14 @@ begin
   {$ifdef VerboseQt}
   Write('TQtDeviceContext.region() ');
   {$endif}
-  if vRegion.Widget=nil then
+  if vRegion.Widget <> nil then
+  begin
+    QRegion_destroy(vRegion.Widget);
+    vRegion.Widget := nil;
+  end;
+  if vRegion.Widget = nil then
     vRegion.Widget := QRegion_Create();
-    
+
   QPainter_clipRegion(Widget,  vRegion.Widget);
   Result := vRegion;
 end;
diff --git a/lcl/interfaces/qt/qtwinapi.inc b/lcl/interfaces/qt/qtwinapi.inc
index 494c108b20..ab9f7eeb6b 100644
--- a/lcl/interfaces/qt/qtwinapi.inc
+++ b/lcl/interfaces/qt/qtwinapi.inc
@@ -2489,7 +2489,7 @@ end;
 function TQtWidgetSet.GetClipRGN(DC : hDC; RGN : hRGN): Longint;
 begin
   {$ifdef VerboseQtWinAPI}
-    Write('Trace: [WinAPI GetClipRgn]',
+    Writeln('Trace: [WinAPI GetClipRgn]',
      ' DC: ', dbghex(DC),
      ' RGN: ', dbghex(Rgn));
     if RGN<>0 then
@@ -2501,13 +2501,21 @@ begin
   Result := -1;
   if not IsValidDC(DC) then
     exit;
-  if rgn=0 then
+  if Rgn = 0 then
     exit;
   if not TQtDeviceContext(DC).getClipping then
     Result := 0
   else
   begin
-    QPainter_ClipRegion(TQtDeviceContext(DC).Widget, TQtRegion(Rgn).Widget);
+    // if our TQtRegion contains widget then
+    // first destroy it because QPainter creates
+    // new reference.
+    if TQtRegion(Rgn).Widget <> nil then
+    begin
+      QRegion_destroy(TQtRegion(Rgn).Widget);
+      TQtRegion(Rgn).Widget := QRegion_create;
+    end;
+    QPainter_clipRegion(TQtDeviceContext(DC).Widget, TQtRegion(Rgn).Widget);
     Result := 1;
   end;
 end;
@@ -4419,26 +4427,33 @@ begin
   if not IsValidDC(DC) then exit;
 
   IntersectRgn := QRegion_create(Left, Top, Right - Left, Bottom - Top);
-  Rgn := QRegion_create;
   try
     if QtDC.getClipping then
     begin
-      QPainter_clipRegion(QtDC.Widget, Rgn);
-      if QRegion_isEmpty(Rgn) then
-        QtDC.setClipRegion(IntersectRgn)
-      else
-        QtDC.setClipRegion(IntersectRgn, QtIntersectClip);
-    end
-    else
+      Rgn := QRegion_create;
+      try
+        QPainter_clipRegion(QtDC.Widget, Rgn);
+        if QRegion_isEmpty(Rgn) then
+          QtDC.setClipRegion(IntersectRgn)
+        else
+          QtDC.setClipRegion(IntersectRgn, QtIntersectClip);
+        QtDC.setClipping(True);
+        // recreate Rgn
+        QRegion_destroy(Rgn);
+        Rgn := QRegion_create;
+        QPainter_clipRegion(QtDC.Widget, Rgn);
+        Result := QtDC.GetRegionType(Rgn);
+      finally
+        QRegion_destroy(Rgn);
+      end;
+    end else
     begin
       QtDC.setClipRegion(InterSectRgn);
-      QPainter_clipRegion(QtDC.Widget, Rgn);
+      QtDC.setClipping(True);
+      Result := QtDC.GetRegionType(InterSectRgn);
     end;
-    QtDC.setClipping(True);
-    Result := QtDC.GetRegionType(Rgn);
   finally
     QRegion_destroy(IntersectRgn);
-    QRegion_destroy(Rgn);
   end;
 end;