Add MSG_LINEBREAK and MSG_LINEBREAK_LEN for mailnews. We need to transition all mailnews use of LINEBREAK to these new macros. I'm leaving the old LINEBREAK definition in place so I don't have to update all files that use it at once. Why can't we use LINEBREAK? Because it is incorrectly defined on the Mac and due to situations outside of our control, we can't change the value of LINEBREAK on the Mac (because it is defined elsewhere and they need it defined incorrectly). So we're going to use these new values (MSG_LINEBREAK and MSG_LINEBREAK_LEN) instead.

mailnews/base/public/msgCore.h

@@ -110,8 +110,7 @@ NS_ERROR_GENERATE_FAILURE(NS_ERROR_MODULE_MAILNEWS, value)
 #define NS_MSG_CANT_CREATE_FOLDER NS_MSG_GENERATE_FAILURE(12)
 
 #ifdef XP_MAC
-#  define LINEBREAK             "\012"		/* ducarroz: it must be defined to \012 to avoid
-														 definition conflit with fe_proto.h */
+#  define LINEBREAK             "\012"
 #  define LINEBREAK_LEN 1
 #else
 #  ifdef XP_WIN
@@ -125,6 +124,21 @@ NS_ERROR_GENERATE_FAILURE(NS_ERROR_MODULE_MAILNEWS, value)
 #  endif /* XP_WIN */
 #endif /* XP_MAC */
 
+#ifdef XP_MAC
+#  define MSG_LINEBREAK             "\015"
+#  define MSG_LINEBREAK_LEN 1
+#else
+#  ifdef XP_WIN
+#    define MSG_LINEBREAK           "\015\012"
+#    define MSG_LINEBREAK_LEN       2
+#  else
+#    ifdef XP_UNIX
+#      define MSG_LINEBREAK         "\012"
+#      define MSG_LINEBREAK_LEN     1
+#    endif /* XP_UNIX */
+#  endif /* XP_WIN */
+#endif /* XP_MAC */
+
 ////////////////////////////////////////////////////////////////////////////////
 // Utilities