Fix wxSpinButton default width under GTK+ 3.

The default GTK+2 width is so small as to make the control unusable under
GTK+3, so use larger (but still hardcoded) width there.

Closes #15619.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@75096 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -574,6 +574,10 @@ All:
 
 - Fix crash if wxCharBuffer fails to allocate the requested amount of memory.
 
+wxGTK:
+
+- Fix wxSpinButton default width under GTK+ 3 (David Hart).
+
 
 3.0-RC2: (released 2013-10-28)
 ------------------------------

src/gtk/spinbutt.cpp

@@ -207,7 +207,13 @@ GdkWindow *wxSpinButton::GTKGetWindow(wxArrayGdkWindows& WXUNUSED(windows)) cons
 
 wxSize wxSpinButton::DoGetBestSize() const
 {
-    wxSize best(15, 26); // FIXME
+    int width =
+#ifdef __WXGTK3__
+    48;
+#else
+    15;
+#endif
+    wxSize best(width, 26); // FIXME
     CacheBestSize(best);
     return best;
 }