Stop curl from trying to POST stdin (arangodb#7098)

goedderz · mchacki · commit c7c838ed30b3 · 2018-10-29T14:41:28.000+01:00
* Stop libcurl from trying to POST stdin

* Stop relocking every iteration in wait

* Restrict setting of empty POSTFIELDS to POST requests

* Revert locking change
diff --git a/lib/SimpleHttpClient/Communicator.cpp b/lib/SimpleHttpClient/Communicator.cpp
@@ -291,10 +291,20 @@ void Communicator::createRequestInProgress(NewRequest&& newRequest) {
 
   CURL* handle = handleInProgress->_handle;
   struct curl_slist* requestHeaders = nullptr;
-  if (request->body().length() > 0) {
+
+  // CURLOPT_POSTFIELDS has to be set for CURLOPT_POST, even if the body is
+  // empty.
+  // Otherwise, curl uses CURLOPT_READFUNCTION on CURLOPT_READDATA, which
+  // default to fread and stdin, respectively: this can cause curl to wait
+  // indefinitely.
+  if (request->body().length() > 0 ||
+      request->requestType() == RequestType::POST) {
     curl_easy_setopt(handle, CURLOPT_POSTFIELDS, request->body().data());
     curl_easy_setopt(handle, CURLOPT_POSTFIELDSIZE, request->body().length());
+  }
 
+  // We still omit the content type on empty bodies.
+  if (request->body().length() > 0) {
     switch (request->contentType()) {
       case ContentType::UNSET:
       case ContentType::CUSTOM:
