- CURLINFO_CONDITION_UNMET was added to allow an application to get to know if

the condition in the previous request was unmet. This is typically a time
  condition set with CURLOPT_TIMECONDITION and was previously not possible to
  reliably figure out. From bug report #2565128
  (http://curl.haxx.se/bug/view.cgi?id=2565128)

include/curl/curl.h

@@ -1592,9 +1592,10 @@ typedef enum {
   CURLINFO_PRIMARY_IP       = CURLINFO_STRING + 32,
   CURLINFO_APPCONNECT_TIME  = CURLINFO_DOUBLE + 33,
   CURLINFO_CERTINFO         = CURLINFO_SLIST  + 34,
+  CURLINFO_CONDITION_UNMET  = CURLINFO_LONG   + 35,
   /* Fill in new entries below here! */
 
-  CURLINFO_LASTONE          = 34
+  CURLINFO_LASTONE          = 35
 } CURLINFO;
 
 /* CURLINFO_RESPONSE_CODE is the new name for the option previously known as