From b96a56e60e65e17704fc66ae9cdbb2444ac987d8 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Sun, 28 Feb 2010 11:09:26 +0000
Subject: [PATCH] Make it possible to use wxCharBuffer during program
 initialization.

wxCharBuffer might be used during static initialization, even if only
implicitly. E.g. it is used by wxString::Format() which can be used to
initialize a global string. But it uses the global s_untypedNullData variable
might not be initialized yet resulting in mysterious failures.

Fix this in the usual way by wrapping access to the variable via a function.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@63585 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 include/wx/buffer.h   |  8 ++------
 src/common/string.cpp | 16 ++++++++++------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/include/wx/buffer.h b/include/wx/buffer.h
index 864bb64eb7..4be2660b67 100644
--- a/include/wx/buffer.h
+++ b/include/wx/buffer.h
@@ -56,12 +56,8 @@ struct UntypedBufferData
     bool m_owned;
 };
 
-// this has to be defined inside the DLL (and not e.g. as a static variable
-// inside an inline function) as otherwise MSVC gives link errors when the
-// functions are effectively inlined (i.e. in non-debug build)
-//
 // NB: this is defined in string.cpp and not the (non-existent) buffer.cpp
-extern WXDLLIMPEXP_DATA_BASE(UntypedBufferData * const) untypedNullDataPtr;
+WXDLLIMPEXP_BASE UntypedBufferData * GetUntypedNullData();
 
 } // namespace wxPrivate
 
@@ -186,7 +182,7 @@ protected:
     // placeholder for NULL string, to simplify this code
     static Data *GetNullData()
     {
-        return static_cast<Data *>(wxPrivate::untypedNullDataPtr);
+        return static_cast<Data *>(wxPrivate::GetUntypedNullData());
     }
 
     void IncRef()
diff --git a/src/common/string.cpp b/src/common/string.cpp
index 9e9ba528fc..dcac014916 100644
--- a/src/common/string.cpp
+++ b/src/common/string.cpp
@@ -57,16 +57,20 @@
     #define wxStringStrlen   wxStrlen
 #endif
 
-// ----------------------------------------------------------------------------
-// global variables
-// ----------------------------------------------------------------------------
-
+// define a function declared in wx/buffer.h here as we don't have buffer.cpp
+// and don't want to add it just because of this simple function
 namespace wxPrivate
 {
 
-static UntypedBufferData s_untypedNullData(NULL, 0);
+// wxXXXBuffer classes can be (implicitly) used during global statics
+// initialization so wrap the status UntypedBufferData variable in a function
+// to make it safe to access it even before all global statics are initialized
+UntypedBufferData *GetUntypedNullData()
+{
+    static UntypedBufferData s_untypedNullData(NULL, 0);
 
-UntypedBufferData * const untypedNullDataPtr = &s_untypedNullData;
+    return &s_untypedNullData;
+}
 
 } // namespace wxPrivate