From 872fcecfad5bb2291800e1daea3aa2e9fedb81a8 Mon Sep 17 00:00:00 2001
From: "Unknown W. Brackets" <checkins@unknownbrackets.org>
Date: Thu, 27 Dec 2018 10:33:32 -0800
Subject: [PATCH] http: Report errors reading discs.

For more clarity when they can't load.
---
 Core/FileLoaders/HTTPFileLoader.cpp | 7 +++++++
 Core/FileLoaders/HTTPFileLoader.h   | 5 +++++
 Core/Loaders.cpp                    | 4 +++-
 Core/Loaders.h                      | 7 +++++++
 4 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/Core/FileLoaders/HTTPFileLoader.cpp b/Core/FileLoaders/HTTPFileLoader.cpp
index f3407d1127..9c14f5b9fb 100644
--- a/Core/FileLoaders/HTTPFileLoader.cpp
+++ b/Core/FileLoaders/HTTPFileLoader.cpp
@@ -29,6 +29,7 @@ void HTTPFileLoader::Prepare() {
 	std::call_once(preparedFlag_, [this](){
 		if (!client_.Resolve(url_.Host().c_str(), url_.Port())) {
 			ERROR_LOG(LOADER, "HTTP request failed, unable to resolve: %s port %d", url_.Host().c_str(), url_.Port());
+			latestError_ = "Could not connect (name not resolved)";
 			return;
 		}
 
@@ -36,12 +37,14 @@ void HTTPFileLoader::Prepare() {
 		Connect();
 		if (!connected_) {
 			ERROR_LOG(LOADER, "HTTP request failed, failed to connect: %s port %d", url_.Host().c_str(), url_.Port());
+			latestError_ = "Could not connect (refused to connect)";
 			return;
 		}
 
 		int err = client_.SendRequest("HEAD", url_.Resource().c_str());
 		if (err < 0) {
 			ERROR_LOG(LOADER, "HTTP request failed, failed to send request: %s port %d", url_.Host().c_str(), url_.Port());
+			latestError_ = "Could not connect (could not request data)";
 			Disconnect();
 			return;
 		}
@@ -52,6 +55,7 @@ void HTTPFileLoader::Prepare() {
 		if (code != 200) {
 			// Leave size at 0, invalid.
 			ERROR_LOG(LOADER, "HTTP request failed, got %03d for %s", code, filename_.c_str());
+			latestError_ = "Could not connect (invalid response)";
 			Disconnect();
 			return;
 		}
@@ -141,6 +145,7 @@ size_t HTTPFileLoader::ReadAt(s64 absolutePos, size_t bytes, void *data, Flags f
 
 	int err = client_.SendRequest("GET", url_.Resource().c_str(), requestHeaders, nullptr);
 	if (err < 0) {
+		latestError_ = "Invalid response reading data";
 		Disconnect();
 		return 0;
 	}
@@ -150,6 +155,7 @@ size_t HTTPFileLoader::ReadAt(s64 absolutePos, size_t bytes, void *data, Flags f
 	int code = client_.ReadResponseHeaders(&readbuf, responseHeaders);
 	if (code != 206) {
 		ERROR_LOG(LOADER, "HTTP server did not respond with range, received code=%03d", code);
+		latestError_ = "Invalid response reading data";
 		Disconnect();
 		return 0;
 	}
@@ -188,6 +194,7 @@ size_t HTTPFileLoader::ReadAt(s64 absolutePos, size_t bytes, void *data, Flags f
 
 	if (!supportedResponse) {
 		ERROR_LOG(LOADER, "HTTP server did not respond with the range we wanted.");
+		latestError_ = "Invalid response reading data";
 		return 0;
 	}
 
diff --git a/Core/FileLoaders/HTTPFileLoader.h b/Core/FileLoaders/HTTPFileLoader.h
index ab4773604f..d853153177 100644
--- a/Core/FileLoaders/HTTPFileLoader.h
+++ b/Core/FileLoaders/HTTPFileLoader.h
@@ -48,6 +48,10 @@ public:
 		cancelConnect_ = true;
 	}
 
+	std::string LatestError() const override {
+		return latestError_;
+	}
+
 private:
 	void Prepare();
 
@@ -67,6 +71,7 @@ private:
 	std::string filename_;
 	bool connected_ = false;
 	bool cancelConnect_ = false;
+	const char *latestError_ = "";
 
 	std::once_flag preparedFlag_;
 	std::mutex readAtMutex_;
diff --git a/Core/Loaders.cpp b/Core/Loaders.cpp
index c901a1245a..14bc31973d 100644
--- a/Core/Loaders.cpp
+++ b/Core/Loaders.cpp
@@ -294,7 +294,9 @@ bool LoadFile(FileLoader **fileLoaderPtr, std::string *error_string) {
 
 	case IdentifiedFileType::ERROR_IDENTIFYING:
 		ERROR_LOG(LOADER, "Could not read file");
-		*error_string = "Error reading file";
+		*error_string = fileLoader ? fileLoader->LatestError() : "";
+		if (error_string->empty())
+			*error_string = "Error reading file";
 		break;
 
 	case IdentifiedFileType::ARCHIVE_RAR:
diff --git a/Core/Loaders.h b/Core/Loaders.h
index 216cc0fcd9..527fa52f5b 100644
--- a/Core/Loaders.h
+++ b/Core/Loaders.h
@@ -93,6 +93,10 @@ public:
 	// Cancel any operations that might block, if possible.
 	virtual void Cancel() {
 	}
+
+	virtual std::string LatestError() const {
+		return "";
+	}
 };
 
 class ProxiedFileLoader : public FileLoader {
@@ -125,6 +129,9 @@ public:
 	void Cancel() override {
 		backend_->Cancel();
 	}
+	std::string LatestError() const override {
+		return backend_->LatestError();
+	}
 
 protected:
 	FileLoader *backend_;