Evaluate CURLINFO_CONDITION_UNMET on zero sized successful transfers (bnc#692260)

diff --git a/zypp/media/MediaCurl.cc b/zypp/media/MediaCurl.cc
index e7c313f..cb27760 100644 (file)
--- a/zypp/media/MediaCurl.cc
+++ b/zypp/media/MediaCurl.cc
@@ -1363,7 +1363,28 @@ void MediaCurl::doGetFileCopyFile( const Pathname & filename , const Pathname &
     }
 
     ret = curl_easy_perform( _curl );
-
+#if CURLVERSION_AT_LEAST(7,19,4)
+    // bnc#692260: If the client sends a request with an If-Modified-Since header
+    // with a future date for the server, the server may respond 200 sending a
+    // zero size file.
+    // curl-7.19.4 introduces CURLINFO_CONDITION_UNMET to check this condition.
+    if ( ftell(file) == 0 && ret == 0 )
+    {
+      long httpReturnCode = 33;
+      if ( curl_easy_getinfo( _curl, CURLINFO_RESPONSE_CODE, &httpReturnCode ) == CURLE_OK && httpReturnCode == 200 )
+      {
+       long conditionUnmet = 33;
+       if ( curl_easy_getinfo( _curl, CURLINFO_CONDITION_UNMET, &conditionUnmet ) == CURLE_OK && conditionUnmet )
+       {
+         WAR << "TIMECONDITION unmet - retry without." << endl;
+         curl_easy_setopt(_curl, CURLOPT_TIMECONDITION, CURL_TIMECOND_NONE);
+         curl_easy_setopt(_curl, CURLOPT_TIMEVALUE, 0L);
+         ret = curl_easy_perform( _curl );
+       }
+      }
+    }
+#endif
+        
     if ( curl_easy_setopt( _curl, CURLOPT_PROGRESSDATA, NULL ) != 0 ) {
       WAR << "Can't unset CURLOPT_PROGRESSDATA: " << _curlError << endl;;
     }