Fix wrong wxStatusBar height in wxMSW in some circumstances.

Creating the status bar before the menu bar but associating it with the frame
after creating the menu bar resulted in a status bar of completely wrong height.
Fix this by enforcing the default height on the status bar when it's attached
to the frame.

Closes #10956.

[This is the backport of r76417 from trunk.]

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@77949 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -620,6 +620,7 @@ wxMSW:
 - Fix height of initially empty wxBitmapComboBox (Artur Wieczorek).
 - Fix setting label of submenu items (Artur Wieczorek).
 - Fix using Esc as accelerator in the menus.
+- Fix wrong initial status bar height in some cases (Artur Wieczorek).
 
 
 3.0.1: (released 2014-06-15)

src/msw/frame.cpp

@@ -286,6 +286,13 @@ void wxFrame::PositionStatusBar()
     int w, h;
     GetClientSize(&w, &h);
 
+    // Resize the status bar to its default height, as it could have been set
+    // to a wrong value before by WM_SIZE sent during the frame creation and
+    // our status bars preserve their programmatically set size to avoid being
+    // resized by DefWindowProc() to the full window width, so if we didn't do
+    // this here, the status bar would retain the possibly wrong current height.
+    m_frameStatusBar->SetSize(wxDefaultSize, wxSIZE_AUTO_HEIGHT);
+
     int sw, sh;
     m_frameStatusBar->GetSize(&sw, &sh);