input/curl: use new class HttpStatusError

This way, IsFileNotFound() can detect status 404.

src/input/Error.cxx

@@ -21,6 +21,10 @@
 #include "Error.hxx"
 #include "system/Error.hxx"
 
+#ifdef ENABLE_CURL
+#include "lib/curl/Error.hxx"
+#endif
+
 #ifdef ENABLE_NFS
 #include "lib/nfs/Error.hxx"
 #include <nfsc/libnfs-raw-nfs.h>
@@ -33,6 +37,10 @@ IsFileNotFound(std::exception_ptr ep)
 		std::rethrow_exception(ep);
 	} catch (const std::system_error &e) {
 		return IsFileNotFound(e);
+#ifdef ENABLE_CURL
+	} catch (const HttpStatusError &e) {
+		return e.GetStatus() == 404;
+#endif
 #ifdef ENABLE_NFS
 	} catch (const NfsClientError &e) {
 		return e.GetCode() == NFS3ERR_NOENT;

src/input/plugins/CurlInputPlugin.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "CurlInputPlugin.hxx"
+#include "lib/curl/Error.hxx"
 #include "lib/curl/Easy.hxx"
 #include "lib/curl/Global.hxx"
 #include "lib/curl/Request.hxx"
@@ -188,7 +189,9 @@ CurlInputStream::OnHeaders(unsigned status,
 	assert(!postponed_exception);
 
 	if (status < 200 || status >= 300)
-		throw FormatRuntimeError("got HTTP status %ld", status);
+		throw HttpStatusError(status,
+				      StringFormat<40>("got HTTP status %u",
+						       status).c_str());
 
 	const std::lock_guard<Mutex> protect(mutex);