Merge pull request #787 from libcpr/put_read_callback

Workaround for PUT requests with a read callback
libcpr · Jul 18, 2022 · 871ed52 · 871ed52
2 parents bda0a75 + d0448eb
commit 871ed52
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Showing 2 changed files with 40 additions and 1 deletion.
diff --git a/cpr/session.cpp b/cpr/session.cpp
@@ -206,7 +206,7 @@ void Session::prepareCommon() {
 
 Response Session::makeRequest() {
     if (!interceptors_.empty()) {
-        // At least one interceptor exists -> Ececute its intercept function
+        // At least one interceptor exists -> Execute its intercept function
         std::shared_ptr<Interceptor> interceptor = interceptors_.front();
         interceptors_.pop();
         return interceptor->intercept(*this);
@@ -836,6 +836,14 @@ void Session::PreparePost() {
 
 void Session::PreparePut() {
     curl_easy_setopt(curl_->handle, CURLOPT_NOBODY, 0L);
+    if (!hasBodyOrPayload_ && readcb_.callback) {
+        /**
+         * Yes, this one has to be CURLOPT_POSTFIELDS even if we are performing a PUT request.
+         * In case we don't set this one, performing a POST-request with PUT won't work.
+         * It in theory this only enforces the usage of the readcallback for POST requests, but works here as well.
+         **/
+        curl_easy_setopt(curl_->handle, CURLOPT_POSTFIELDS, nullptr);
+    }
     curl_easy_setopt(curl_->handle, CURLOPT_CUSTOMREQUEST, "PUT");
     curl_easy_setopt(curl_->handle, CURLOPT_RANGE, nullptr);
     prepareCommon();

diff --git a/test/callback_tests.cpp b/test/callback_tests.cpp
@@ -767,6 +767,37 @@ TEST(CallbackDataTests, CallbackReadFunctionTextTest) {
     EXPECT_EQ(expected_text, response.text);
 }
 
+TEST(CallbackDataTests, CallbackReadFunctionTextTestPut) {
+    Url url{server->GetBaseUrl() + "/put.html"};
+    std::string expected_text{
+            "{\n"
+            "  \"x\": 5\n"
+            "}"};
+    unsigned count = 0;
+    Response response = cpr::Put(url, cpr::ReadCallback{3, [&](char* buffer, size_t& size, intptr_t /*userdata*/) -> size_t {
+                                                            std::string data;
+                                                            ++count;
+                                                            switch (count) {
+                                                                case 1:
+                                                                    data = "x=";
+                                                                    break;
+                                                                case 2:
+                                                                    data = "5";
+                                                                    break;
+                                                                default:
+                                                                    return false;
+                                                            }
+                                                            std::copy(data.begin(), data.end(), buffer);
+                                                            size = data.size();
+                                                            return true;
+                                                        }});
+    EXPECT_EQ(2, count);
+    EXPECT_EQ(expected_text, response.text);
+    EXPECT_EQ(std::string{"application/json"}, response.header["content-type"]);
+    EXPECT_EQ(200, response.status_code);
+    EXPECT_EQ(ErrorCode::OK, response.error.code);
+}
+
 /**
  * Checks if the "Transfer-Encoding" header will be kept when using headers and a read callback.
  * Issue: https://github.com/whoshuu/cpr/issues/517