1. wxThread changes (detached/joinable) for MSW and docs updates

2. wxUSE_GUI=0 compilation for MSW (use vc6dll.t with tmake) and many small
   fixes related to this
3. an attempt to make wxLog more MT friendly
4. a small fix for wxRegConfig: it doesn't create empty unused keys any
   more (SetPath() would always create a key, now it's deleted if it was
   empty)


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@4712 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/string.cpp

@@ -200,7 +200,12 @@ extern int WXDLLEXPORT wxVsnprintf(wxChar *buf, size_t len,
 
     return iLen;
 #else // ANSI
-    return wxVsnprintfA(buf, len, format, argptr);
+    // vsnprintf() will not terminate the string with '\0' if there is not
+    // enough place, but we want the string to always be NUL terminated
+    int rc = wxVsnprintfA(buf, len - 1, format, argptr);
+    buf[len] = 0;
+
+    return rc;
 #endif // Unicode/ANSI
 }