fix crash in ~wxString with global wxString objects: temporarily move conversion buffers from a hash to wxString

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@45335 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/string.h

@@ -571,8 +571,6 @@ public:
   wxString(const wxString& str, size_t nLength)
       : m_impl(str.Mid(0, nLength).m_impl) {}
 
-  ~wxString();
-
 public:
   // standard types
   typedef wxUniChar value_type;
@@ -2001,6 +1999,35 @@ private:
 
 private:
   wxStringImpl m_impl;
+
+  // buffers for compatibility conversion from (char*)c_str() and
+  // (wchar_t*)c_str():
+  // FIXME-UTF8: bechmark various approaches to keeping compatibility buffers
+  template<typename T>
+  struct ConvertedBuffer
+  {
+      ConvertedBuffer() : m_buf(NULL) {}
+      ~ConvertedBuffer()
+          { free(m_buf); }
+
+      operator const T*() const { return m_buf; }
+
+      ConvertedBuffer& operator=(T *str)
+      {
+          free(m_buf);
+          m_buf = str;
+          return *this;
+      }
+
+      T *m_buf;
+  };
+#if wxUSE_UNICODE
+  ConvertedBuffer<char> m_convertedToChar;
+#endif
+#if !wxUSE_UNICODE_WCHAR
+  ConvertedBuffer<wchar_t> m_convertedToWChar;
+#endif
+  friend class WXDLLIMPEXP_BASE wxCStrData;
 };
 
 #ifdef wxNEEDS_WXSTRING_PRINTF_MIXIN

src/common/string.cpp

@@ -109,6 +109,11 @@ wxSTD ostream& operator<<(wxSTD ostream& os, const wxWCharBuffer& str)
 // wxCStrData converted strings caching
 // ----------------------------------------------------------------------------
 
+// FIXME-UTF8: temporarily disabled because it doesn't work with global
+//             string objects; re-enable after fixing this bug and benchmarking
+//             performance to see if using a hash is a good idea at all
+#if 0
+
 // For backward compatibility reasons, it must be possible to assign the value
 // returned by wxString::c_str() to a char* or wchar_t* variable and work with
 // it. Returning wxCharBuffer from (const char*)c_str() wouldn't do the trick,
@@ -177,14 +182,6 @@ const wchar_t* wxCStrData::AsWChar() const
 }
 #endif // !wxUSE_UNICODE_WCHAR
 
-// ===========================================================================
-// wxString class core
-// ===========================================================================
-
-// ---------------------------------------------------------------------------
-// construction and conversion
-// ---------------------------------------------------------------------------
-
 wxString::~wxString()
 {
 #if wxUSE_UNICODE
@@ -195,6 +192,35 @@ wxString::~wxString()
     DeleteStringFromConversionCache(gs_stringsWCharCache, this);
 #endif
 }
+#endif
+
+#if wxUSE_UNICODE
+const char* wxCStrData::AsChar() const
+{
+    wxString *str = wxConstCast(m_str, wxString);
+    // convert the string and keep it:
+    str->m_convertedToChar = str->mb_str().release();
+    return str->m_convertedToChar + m_offset;
+}
+#endif // wxUSE_UNICODE
+
+#if !wxUSE_UNICODE_WCHAR
+const wchar_t* wxCStrData::AsWChar() const
+{
+    wxString *str = wxConstCast(m_str, wxString);
+    // convert the string and keep it:
+    str->m_convertedToWChar = str->wc_str().release();
+    return str->m_convertedToWChar + m_offset;
+}
+#endif // !wxUSE_UNICODE_WCHAR
+
+// ===========================================================================
+// wxString class core
+// ===========================================================================
+
+// ---------------------------------------------------------------------------
+// construction and conversion
+// ---------------------------------------------------------------------------
 
 #if wxUSE_UNICODE
 /* static */