diff --git a/docs/changes.txt b/docs/changes.txt
index 2d77036063..bb79b65387 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -461,6 +461,7 @@ All (GUI):
 - wxPropertyGrid: Added "HasAlpha" attribute for wxColourProperty.
 - Added support for saving PNG files with palette (troelsk).
 - Added support for saving as GIF and animated GIF (troelsk).
+- Fix wxWrapSizer minimal size calculation (Catalin Raceanu).
 
 GTK:
 
diff --git a/include/wx/sizer.h b/include/wx/sizer.h
index 6d414fd09d..39044e31e8 100644
--- a/include/wx/sizer.h
+++ b/include/wx/sizer.h
@@ -665,6 +665,10 @@ public:
         m_position = pos;
         m_size = size;
         Layout();
+
+        // This call is required for wxWrapSizer to be able to calculate its
+        // minimal size correctly.
+        InformFirstDirection(wxHORIZONTAL, size.x, size.y);
     }
     void SetDimension(int x, int y, int width, int height)
         { SetDimension(wxPoint(x, y), wxSize(width, height)); }
diff --git a/include/wx/window.h b/include/wx/window.h
index 1527a1e0de..0fd842426a 100644
--- a/include/wx/window.h
+++ b/include/wx/window.h
@@ -525,12 +525,7 @@ public:
     // tells the item how much more space there is available in the opposite
     // direction (-1 if unknown).
     virtual bool
-    InformFirstDirection(int WXUNUSED(direction),
-                         int WXUNUSED(size),
-                         int WXUNUSED(availableOtherDir))
-    {
-        return false;
-    }
+    InformFirstDirection(int direction, int size, int availableOtherDir);
 
     // sends a size event to the window using its current size -- this has an
     // effect of refreshing the window layout
diff --git a/src/common/wincmn.cpp b/src/common/wincmn.cpp
index 76aca9086c..2c58ce1ec1 100644
--- a/src/common/wincmn.cpp
+++ b/src/common/wincmn.cpp
@@ -853,6 +853,16 @@ wxSize wxWindowBase::GetWindowBorderSize() const
     return size*2;
 }
 
+bool
+wxWindowBase::InformFirstDirection(int direction,
+                                   int size,
+                                   int availableOtherDir)
+{
+    return GetSizer() && GetSizer()->InformFirstDirection(direction,
+                                                          size,
+                                                          availableOtherDir);
+}
+
 wxSize wxWindowBase::GetEffectiveMinSize() const
 {
     // merge the best size with the min size, giving priority to the min size
diff --git a/tests/Makefile.in b/tests/Makefile.in
index 9a1f9abb78..9c57cd3d22 100644
--- a/tests/Makefile.in
+++ b/tests/Makefile.in
@@ -213,6 +213,7 @@ TEST_GUI_OBJECTS =  \
 	test_gui_settings.o \
 	test_gui_socket.o \
 	test_gui_boxsizer.o \
+	test_gui_wrapsizer.o \
 	test_gui_valnum.o \
 	test_gui_clientsize.o \
 	test_gui_setsize.o \
@@ -868,6 +869,9 @@ test_gui_socket.o: $(srcdir)/net/socket.cpp $(TEST_GUI_ODEP)
 test_gui_boxsizer.o: $(srcdir)/sizers/boxsizer.cpp $(TEST_GUI_ODEP)
 	$(CXXC) -c -o $@ $(TEST_GUI_CXXFLAGS) $(srcdir)/sizers/boxsizer.cpp
 
+test_gui_wrapsizer.o: $(srcdir)/sizers/wrapsizer.cpp $(TEST_GUI_ODEP)
+	$(CXXC) -c -o $@ $(TEST_GUI_CXXFLAGS) $(srcdir)/sizers/wrapsizer.cpp
+
 test_gui_valnum.o: $(srcdir)/validators/valnum.cpp $(TEST_GUI_ODEP)
 	$(CXXC) -c -o $@ $(TEST_GUI_CXXFLAGS) $(srcdir)/validators/valnum.cpp
 
diff --git a/tests/makefile.bcc b/tests/makefile.bcc
index 5b9060338d..f6a49b636b 100644
--- a/tests/makefile.bcc
+++ b/tests/makefile.bcc
@@ -195,12 +195,13 @@ TEST_GUI_OBJECTS =  \
 	$(OBJS)\test_gui_guifuncs.obj \
 	$(OBJS)\test_gui_selstoretest.obj \
 	$(OBJS)\test_gui_garbage.obj \
-	$(OBJS)\test_gui_settings.obj \
-	$(OBJS)\test_gui_socket.obj \
-	$(OBJS)\test_gui_boxsizer.obj \
-	$(OBJS)\test_gui_valnum.obj \
-	$(OBJS)\test_gui_clientsize.obj \
-	$(OBJS)\test_gui_setsize.obj \
+	$(OBJS)\test_gui_settings.obj \
+	$(OBJS)\test_gui_socket.obj \
+	$(OBJS)\test_gui_boxsizer.obj \
+	$(OBJS)\test_gui_wrapsizer.obj \
+	$(OBJS)\test_gui_valnum.obj \
+	$(OBJS)\test_gui_clientsize.obj \
+	$(OBJS)\test_gui_setsize.obj \
 	$(OBJS)\test_gui_xrctest.obj
 
 ### Conditionally set variables: ###
@@ -913,12 +914,15 @@ $(OBJS)\test_gui_settings.obj: .\misc\settings.cpp
 $(OBJS)\test_gui_socket.obj: .\net\socket.cpp
 	$(CXX) -q -c -P -o$@ $(TEST_GUI_CXXFLAGS) .\net\socket.cpp
 
-$(OBJS)\test_gui_boxsizer.obj: .\sizers\boxsizer.cpp
-	$(CXX) -q -c -P -o$@ $(TEST_GUI_CXXFLAGS) .\sizers\boxsizer.cpp
-
-$(OBJS)\test_gui_valnum.obj: .\validators\valnum.cpp
-	$(CXX) -q -c -P -o$@ $(TEST_GUI_CXXFLAGS) .\validators\valnum.cpp
-
+$(OBJS)\test_gui_boxsizer.obj: .\sizers\boxsizer.cpp
+	$(CXX) -q -c -P -o$@ $(TEST_GUI_CXXFLAGS) .\sizers\boxsizer.cpp
+
+$(OBJS)\test_gui_wrapsizer.obj: .\sizers\wrapsizer.cpp
+	$(CXX) -q -c -P -o$@ $(TEST_GUI_CXXFLAGS) .\sizers\wrapsizer.cpp
+
+$(OBJS)\test_gui_valnum.obj: .\validators\valnum.cpp
+	$(CXX) -q -c -P -o$@ $(TEST_GUI_CXXFLAGS) .\validators\valnum.cpp
+
 $(OBJS)\test_gui_clientsize.obj: .\window\clientsize.cpp
 	$(CXX) -q -c -P -o$@ $(TEST_GUI_CXXFLAGS) .\window\clientsize.cpp
 
diff --git a/tests/makefile.gcc b/tests/makefile.gcc
index f7829a341b..52490dd62f 100644
--- a/tests/makefile.gcc
+++ b/tests/makefile.gcc
@@ -188,12 +188,13 @@ TEST_GUI_OBJECTS =  \
 	$(OBJS)\test_gui_guifuncs.o \
 	$(OBJS)\test_gui_selstoretest.o \
 	$(OBJS)\test_gui_garbage.o \
-	$(OBJS)\test_gui_settings.o \
-	$(OBJS)\test_gui_socket.o \
-	$(OBJS)\test_gui_boxsizer.o \
-	$(OBJS)\test_gui_valnum.o \
-	$(OBJS)\test_gui_clientsize.o \
-	$(OBJS)\test_gui_setsize.o \
+	$(OBJS)\test_gui_settings.o \
+	$(OBJS)\test_gui_socket.o \
+	$(OBJS)\test_gui_boxsizer.o \
+	$(OBJS)\test_gui_wrapsizer.o \
+	$(OBJS)\test_gui_valnum.o \
+	$(OBJS)\test_gui_clientsize.o \
+	$(OBJS)\test_gui_setsize.o \
 	$(OBJS)\test_gui_xrctest.o
 
 ### Conditionally set variables: ###
@@ -894,12 +895,15 @@ $(OBJS)\test_gui_settings.o: ./misc/settings.cpp
 $(OBJS)\test_gui_socket.o: ./net/socket.cpp
 	$(CXX) -c -o $@ $(TEST_GUI_CXXFLAGS) $(CPPDEPS) $<
 
-$(OBJS)\test_gui_boxsizer.o: ./sizers/boxsizer.cpp
-	$(CXX) -c -o $@ $(TEST_GUI_CXXFLAGS) $(CPPDEPS) $<
-
-$(OBJS)\test_gui_valnum.o: ./validators/valnum.cpp
-	$(CXX) -c -o $@ $(TEST_GUI_CXXFLAGS) $(CPPDEPS) $<
-
+$(OBJS)\test_gui_boxsizer.o: ./sizers/boxsizer.cpp
+	$(CXX) -c -o $@ $(TEST_GUI_CXXFLAGS) $(CPPDEPS) $<
+
+$(OBJS)\test_gui_wrapsizer.o: ./sizers/wrapsizer.cpp
+	$(CXX) -c -o $@ $(TEST_GUI_CXXFLAGS) $(CPPDEPS) $<
+
+$(OBJS)\test_gui_valnum.o: ./validators/valnum.cpp
+	$(CXX) -c -o $@ $(TEST_GUI_CXXFLAGS) $(CPPDEPS) $<
+
 $(OBJS)\test_gui_clientsize.o: ./window/clientsize.cpp
 	$(CXX) -c -o $@ $(TEST_GUI_CXXFLAGS) $(CPPDEPS) $<
 
diff --git a/tests/makefile.vc b/tests/makefile.vc
index 2af1e2cfa5..19f365c0ad 100644
--- a/tests/makefile.vc
+++ b/tests/makefile.vc
@@ -190,12 +190,13 @@ TEST_GUI_OBJECTS =  \
 	$(OBJS)\test_gui_guifuncs.obj \
 	$(OBJS)\test_gui_selstoretest.obj \
 	$(OBJS)\test_gui_garbage.obj \
-	$(OBJS)\test_gui_settings.obj \
-	$(OBJS)\test_gui_socket.obj \
-	$(OBJS)\test_gui_boxsizer.obj \
-	$(OBJS)\test_gui_valnum.obj \
-	$(OBJS)\test_gui_clientsize.obj \
-	$(OBJS)\test_gui_setsize.obj \
+	$(OBJS)\test_gui_settings.obj \
+	$(OBJS)\test_gui_socket.obj \
+	$(OBJS)\test_gui_boxsizer.obj \
+	$(OBJS)\test_gui_wrapsizer.obj \
+	$(OBJS)\test_gui_valnum.obj \
+	$(OBJS)\test_gui_clientsize.obj \
+	$(OBJS)\test_gui_setsize.obj \
 	$(OBJS)\test_gui_xrctest.obj
 TEST_GUI_RESOURCES =  \
 	$(OBJS)\test_gui_sample.res
@@ -1039,12 +1040,15 @@ $(OBJS)\test_gui_settings.obj: .\misc\settings.cpp
 $(OBJS)\test_gui_socket.obj: .\net\socket.cpp
 	$(CXX) /c /nologo /TP /Fo$@ $(TEST_GUI_CXXFLAGS) .\net\socket.cpp
 
-$(OBJS)\test_gui_boxsizer.obj: .\sizers\boxsizer.cpp
-	$(CXX) /c /nologo /TP /Fo$@ $(TEST_GUI_CXXFLAGS) .\sizers\boxsizer.cpp
-
-$(OBJS)\test_gui_valnum.obj: .\validators\valnum.cpp
-	$(CXX) /c /nologo /TP /Fo$@ $(TEST_GUI_CXXFLAGS) .\validators\valnum.cpp
-
+$(OBJS)\test_gui_boxsizer.obj: .\sizers\boxsizer.cpp
+	$(CXX) /c /nologo /TP /Fo$@ $(TEST_GUI_CXXFLAGS) .\sizers\boxsizer.cpp
+
+$(OBJS)\test_gui_wrapsizer.obj: .\sizers\wrapsizer.cpp
+	$(CXX) /c /nologo /TP /Fo$@ $(TEST_GUI_CXXFLAGS) .\sizers\wrapsizer.cpp
+
+$(OBJS)\test_gui_valnum.obj: .\validators\valnum.cpp
+	$(CXX) /c /nologo /TP /Fo$@ $(TEST_GUI_CXXFLAGS) .\validators\valnum.cpp
+
 $(OBJS)\test_gui_clientsize.obj: .\window\clientsize.cpp
 	$(CXX) /c /nologo /TP /Fo$@ $(TEST_GUI_CXXFLAGS) .\window\clientsize.cpp
 
diff --git a/tests/makefile.wat b/tests/makefile.wat
index ba5ae182f5..6500836f23 100644
--- a/tests/makefile.wat
+++ b/tests/makefile.wat
@@ -434,12 +434,13 @@ TEST_GUI_OBJECTS =  &
 	$(OBJS)\test_gui_guifuncs.obj &
 	$(OBJS)\test_gui_selstoretest.obj &
 	$(OBJS)\test_gui_garbage.obj &
-	$(OBJS)\test_gui_settings.obj &
-	$(OBJS)\test_gui_socket.obj &
-	$(OBJS)\test_gui_boxsizer.obj &
-	$(OBJS)\test_gui_valnum.obj &
-	$(OBJS)\test_gui_clientsize.obj &
-	$(OBJS)\test_gui_setsize.obj &
+	$(OBJS)\test_gui_settings.obj &
+	$(OBJS)\test_gui_socket.obj &
+	$(OBJS)\test_gui_boxsizer.obj &
+	$(OBJS)\test_gui_wrapsizer.obj &
+	$(OBJS)\test_gui_valnum.obj &
+	$(OBJS)\test_gui_clientsize.obj &
+	$(OBJS)\test_gui_setsize.obj &
 	$(OBJS)\test_gui_xrctest.obj
 
 
@@ -953,12 +954,15 @@ $(OBJS)\test_gui_settings.obj :  .AUTODEPEND .\misc\settings.cpp
 $(OBJS)\test_gui_socket.obj :  .AUTODEPEND .\net\socket.cpp
 	$(CXX) -bt=nt -zq -fo=$^@ $(TEST_GUI_CXXFLAGS) $<
 
-$(OBJS)\test_gui_boxsizer.obj :  .AUTODEPEND .\sizers\boxsizer.cpp
-	$(CXX) -bt=nt -zq -fo=$^@ $(TEST_GUI_CXXFLAGS) $<
-
-$(OBJS)\test_gui_valnum.obj :  .AUTODEPEND .\validators\valnum.cpp
-	$(CXX) -bt=nt -zq -fo=$^@ $(TEST_GUI_CXXFLAGS) $<
-
+$(OBJS)\test_gui_boxsizer.obj :  .AUTODEPEND .\sizers\boxsizer.cpp
+	$(CXX) -bt=nt -zq -fo=$^@ $(TEST_GUI_CXXFLAGS) $<
+
+$(OBJS)\test_gui_wrapsizer.obj :  .AUTODEPEND .\sizers\wrapsizer.cpp
+	$(CXX) -bt=nt -zq -fo=$^@ $(TEST_GUI_CXXFLAGS) $<
+
+$(OBJS)\test_gui_valnum.obj :  .AUTODEPEND .\validators\valnum.cpp
+	$(CXX) -bt=nt -zq -fo=$^@ $(TEST_GUI_CXXFLAGS) $<
+
 $(OBJS)\test_gui_clientsize.obj :  .AUTODEPEND .\window\clientsize.cpp
 	$(CXX) -bt=nt -zq -fo=$^@ $(TEST_GUI_CXXFLAGS) $<
 
diff --git a/tests/sizers/wrapsizer.cpp b/tests/sizers/wrapsizer.cpp
new file mode 100644
index 0000000000..a5d857527d
--- /dev/null
+++ b/tests/sizers/wrapsizer.cpp
@@ -0,0 +1,128 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        tests/sizers/wrapsizer.cpp
+// Purpose:     Unit tests for wxWrapSizer
+// Author:      Catalin Raceanu
+// Created:     2010-10-23
+// RCS-ID:      $Id:$
+// Copyright:   (c) 2010 wxWidgets development team
+///////////////////////////////////////////////////////////////////////////////
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
+#include "testprec.h"
+
+#ifdef __BORLANDC__
+    #pragma hdrstop
+#endif
+
+#ifndef WX_PRECOMP
+    #include "wx/app.h"
+#endif // WX_PRECOMP
+
+#include "wx/wrapsizer.h"
+
+#include "asserthelper.h"
+
+// ----------------------------------------------------------------------------
+// test class
+// ----------------------------------------------------------------------------
+
+class WrapSizerTestCase : public CppUnit::TestCase
+{
+public:
+    WrapSizerTestCase() { }
+
+    virtual void setUp();
+    virtual void tearDown();
+
+private:
+    CPPUNIT_TEST_SUITE( WrapSizerTestCase );
+        CPPUNIT_TEST( CalcMin );
+    CPPUNIT_TEST_SUITE_END();
+
+    void CalcMin();
+
+    wxWindow *m_win;
+    wxSizer *m_sizer;
+
+    DECLARE_NO_COPY_CLASS(WrapSizerTestCase)
+};
+
+// register in the unnamed registry so that these tests are run by default
+CPPUNIT_TEST_SUITE_REGISTRATION( WrapSizerTestCase );
+
+// also include in it's own registry so that these tests can be run alone
+CPPUNIT_TEST_SUITE_NAMED_REGISTRATION( WrapSizerTestCase, "WrapSizerTestCase" );
+
+// ----------------------------------------------------------------------------
+// test initialization
+// ----------------------------------------------------------------------------
+
+void WrapSizerTestCase::setUp()
+{
+    m_win = new wxWindow(wxTheApp->GetTopWindow(), wxID_ANY);
+    m_win->SetClientSize(180, 240);
+
+    m_sizer = new wxWrapSizer(wxHORIZONTAL);
+    m_win->SetSizer(m_sizer);
+}
+
+void WrapSizerTestCase::tearDown()
+{
+    delete m_win;
+    m_win = NULL;
+
+    m_sizer = NULL;
+}
+
+// ----------------------------------------------------------------------------
+// tests themselves
+// ----------------------------------------------------------------------------
+
+void WrapSizerTestCase::CalcMin()
+{
+    const wxSize sizeTotal = m_win->GetClientSize();
+    wxSize sizeMinExpected;
+
+    // With a single child the min size must be the same as child size.
+    const wxSize sizeChild1 = wxSize(sizeTotal.x/2 - 10, sizeTotal.y/4);
+    sizeMinExpected = sizeChild1;
+
+    wxWindow * const
+        child1 = new wxWindow(m_win, wxID_ANY, wxDefaultPosition, sizeChild1);
+    child1->SetBackgroundColour(*wxRED);
+    m_sizer->Add(child1);
+    m_win->Layout();
+
+    CPPUNIT_ASSERT_EQUAL( sizeMinExpected, m_sizer->CalcMin() );
+
+    // If both children can fit in the same row, the minimal size of the sizer
+    // is determined by the sum of their minimal horizontal dimensions and
+    // the maximum of their minimal vertical dimensions.
+    const wxSize sizeChild2 = wxSize(sizeTotal.x/2 + 10, sizeTotal.y/3);
+    sizeMinExpected.x += sizeChild2.x;
+    sizeMinExpected.y = wxMax(sizeChild1.y, sizeChild2.y);
+
+    wxWindow * const
+        child2 = new wxWindow(m_win, wxID_ANY, wxDefaultPosition, sizeChild2);
+    child2->SetBackgroundColour(*wxYELLOW);
+    m_sizer->Add(child2);
+    m_win->Layout();
+
+    CPPUNIT_ASSERT_EQUAL( sizeMinExpected, m_sizer->CalcMin() );
+
+    // Three children will take at least two rows so the minimal size in
+    // vertical direction must increase.
+    const wxSize sizeChild3 = wxSize(sizeTotal.x/2, sizeTotal.y/5);
+    sizeMinExpected.y += sizeChild3.y;
+
+    wxWindow * const
+        child3 = new wxWindow(m_win, wxID_ANY, wxDefaultPosition, sizeChild3);
+    child3->SetBackgroundColour(*wxGREEN);
+    m_sizer->Add(child3);
+    m_win->Layout();
+
+    CPPUNIT_ASSERT_EQUAL( sizeMinExpected, m_sizer->CalcMin() );
+}
diff --git a/tests/test.bkl b/tests/test.bkl
index 33d577ece2..bea939d1ae 100644
--- a/tests/test.bkl
+++ b/tests/test.bkl
@@ -199,6 +199,7 @@
              -->
             net/socket.cpp
             sizers/boxsizer.cpp
+            sizers/wrapsizer.cpp
             validators/valnum.cpp
             window/clientsize.cpp
             window/setsize.cpp
diff --git a/tests/test_test_gui.dsp b/tests/test_test_gui.dsp
index 9d31a564d0..382ecd8890 100644
--- a/tests/test_test_gui.dsp
+++ b/tests/test_test_gui.dsp
@@ -529,6 +529,10 @@ SOURCE=.\controls\windowtest.cpp
 # End Source File
 # Begin Source File
 
+SOURCE=.\sizers\wrapsizer.cpp
+# End Source File
+# Begin Source File
+
 SOURCE=.\xml\xrctest.cpp
 # End Source File
 # End Group
diff --git a/tests/test_vc7_test_gui.vcproj b/tests/test_vc7_test_gui.vcproj
index 9f23cd81e4..d2bd4c2d73 100644
--- a/tests/test_vc7_test_gui.vcproj
+++ b/tests/test_vc7_test_gui.vcproj
@@ -830,6 +830,9 @@
 				RelativePath=".\controls\windowtest.cpp">
 			</File>
 			<File
+				RelativePath=".\sizers\wrapsizer.cpp">
+			</File>
+			<File
 				RelativePath=".\xml\xrctest.cpp">
 			</File>
 		</Filter>
diff --git a/tests/test_vc8_test_gui.vcproj b/tests/test_vc8_test_gui.vcproj
index d4d9c62f0f..8099a9a808 100644
--- a/tests/test_vc8_test_gui.vcproj
+++ b/tests/test_vc8_test_gui.vcproj
@@ -1180,6 +1180,10 @@
 				>
 			</File>
 			<File
+				RelativePath=".\sizers\wrapsizer.cpp"
+				>
+			</File>
+			<File
 				RelativePath=".\xml\xrctest.cpp"
 				>
 			</File>
diff --git a/tests/test_vc9_test_gui.vcproj b/tests/test_vc9_test_gui.vcproj
index f349958217..c11080f593 100644
--- a/tests/test_vc9_test_gui.vcproj
+++ b/tests/test_vc9_test_gui.vcproj
@@ -1152,6 +1152,10 @@
 				>
 			</File>
 			<File
+				RelativePath=".\sizers\wrapsizer.cpp"
+				>
+			</File>
+			<File
 				RelativePath=".\xml\xrctest.cpp"
 				>
 			</File>