XML_UNICODE_WCHAR_T is not suitable for use where sizeof(wchar_t) != 2. That includes Linux at least, so let's just not do this on Unix at all for now. a=donm

expat/xmltok/xmldef.h

@@ -53,5 +53,7 @@ particular environments. */
 #endif /* MOZILLA */
 
 // Enable Unicode string processing in expat
+#ifndef XP_UNIX
 #define XML_UNICODE_WCHAR_T
-#define XML_UNICODE
+#endif
+#define XML_UNICODE

parser/expat/lib/xmldef.h

@@ -53,5 +53,7 @@ particular environments. */
 #endif /* MOZILLA */
 
 // Enable Unicode string processing in expat
+#ifndef XP_UNIX
 #define XML_UNICODE_WCHAR_T
-#define XML_UNICODE
+#endif
+#define XML_UNICODE