multi: prevent NULL pointer dereference

My additional call to Curl_pgrsUpdate() would sometimes get
called even though there's no connection (left) so a NULL pointer
would get passed, causing a segfault.

diff --git a/lib/multi.c b/lib/multi.c
index b42f68d0f2f98be87b481d1c761e060d9785e192..ea284b3f300f3e1ed41be6f92d1f54bfdc1ced71 100644 (file)
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -1527,7 +1527,8 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
 
         multistate(easy, CURLM_STATE_COMPLETED);
       }
-      else if(Curl_pgrsUpdate(easy->easy_conn))
+      /* if there's still a connection to use, call the progress function */
+      else if(easy->easy_conn && Curl_pgrsUpdate(easy->easy_conn))
         easy->result = CURLE_ABORTED_BY_CALLBACK;
     }
   } while(0);