fix compiler warning: zero used for undefined preprocessing identifier

diff --git a/include/curl/curl.h b/include/curl/curl.h
index d6db92fb72c18105d2afd473e883683db16401f5..7a0960f0389c5b0e282d34d7d7c15f90d04a2b24 100644 (file)
--- a/include/curl/curl.h
+++ b/include/curl/curl.h
@@ -1779,7 +1779,8 @@ CURL_EXTERN CURLcode curl_easy_pause(CURL *handle, int bitmask);
 #include "multi.h"
 
 /* the typechecker doesn't work in C++ (yet) */
-#if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)) && \
+#if defined(__GNUC__) && defined(__GNUC_MINOR__) && \
+    ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)) && \
     !defined(__cplusplus) && !defined(CURL_DISABLE_TYPECHECK)
 #include "typecheck-gcc.h"
 #else