lib/curl/Slist: new wrapper for curl_slist

Makefile.am

@@ -1285,6 +1285,7 @@ libinput_a_SOURCES += \
 	src/lib/curl/Handler.hxx \
 	src/lib/curl/Easy.hxx \
 	src/lib/curl/Multi.hxx \
+	src/lib/curl/Slist.hxx \
 	src/IcyMetaDataParser.cxx src/IcyMetaDataParser.hxx
 endif
 

src/input/plugins/CurlInputPlugin.cxx

@@ -23,6 +23,7 @@
 #include "lib/curl/Global.hxx"
 #include "lib/curl/Request.hxx"
 #include "lib/curl/Handler.hxx"
+#include "lib/curl/Slist.hxx"
 #include "../AsyncInputStream.hxx"
 #include "../IcyInputStream.hxx"
 #include "../InputPlugin.hxx"
@@ -64,7 +65,7 @@ struct CurlInputStream final : public AsyncInputStream, CurlResponseHandler {
 	/* some buffers which were passed to libcurl, which we have
 	   too free */
 	char range[32];
-	struct curl_slist *request_headers;
+	CurlSlist request_headers;
 
 	CurlRequest *request = nullptr;
 
@@ -75,7 +76,6 @@ struct CurlInputStream final : public AsyncInputStream, CurlResponseHandler {
 		:AsyncInputStream(_url, _mutex, _cond,
 				  CURL_MAX_BUFFERED,
 				  CURL_RESUME_AT),
-		 request_headers(nullptr),
 		 icy(new IcyInputStream(this)) {
 	}
 
@@ -155,8 +155,7 @@ CurlInputStream::FreeEasy()
 	delete request;
 	request = nullptr;
 
-	curl_slist_free_all(request_headers);
-	request_headers = nullptr;
+	request_headers.Clear();
 }
 
 void
@@ -371,10 +370,9 @@ CurlInputStream::InitEasy()
 	request->SetOption(CURLOPT_SSL_VERIFYPEER, verify_peer ? 1l : 0l);
 	request->SetOption(CURLOPT_SSL_VERIFYHOST, verify_host ? 2l : 0l);
 
-	request_headers = nullptr;
-	request_headers = curl_slist_append(request_headers,
-					    "Icy-Metadata: 1");
-	request->SetOption(CURLOPT_HTTPHEADER, request_headers);
+	request_headers.Clear();
+	request_headers.Append("Icy-Metadata: 1");
+	request->SetOption(CURLOPT_HTTPHEADER, request_headers.Get());
 }
 
 void

src/lib/curl/Slist.hxx

+/*
+ * Copyright (C) 2008-2017 Max Kellermann <max@duempel.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef CURL_SLIST_HXX
+#define CURL_SLIST_HXX
+
+#include <curl/curl.h>
+
+#include <algorithm>
+
+/**
+ * OO wrapper for "struct curl_slist *".
+ */
+class CurlSlist {
+	struct curl_slist *head = nullptr;
+
+public:
+	CurlSlist() = default;
+
+	CurlSlist(CurlSlist &&src)
+		:head(std::exchange(src.head, nullptr)) {}
+
+	~CurlSlist() {
+		if (head != nullptr)
+			curl_slist_free_all(head);
+	}
+
+	CurlSlist &operator=(CurlSlist &&src) {
+		std::swap(head, src.head);
+		return *this;
+	}
+
+	struct curl_slist *Get() {
+		return head;
+	}
+
+	void Clear() {
+		curl_slist_free_all(head);
+		head = nullptr;
+	}
+
+	void Append(const char *value) {
+		auto *new_head = curl_slist_append(head, value);
+		if (new_head == nullptr)
+			throw std::runtime_error("curl_slist_append() failed");
+		head = new_head;
+	}
+};
+
+#endif