Detect and report missing local libraries.

logic/OneSixLibrary.cpp

@@ -140,33 +140,32 @@ QString OneSixLibrary::hint() const
 	return m_hint;
 }
 
-bool OneSixLibrary::filesExist()
+QStringList OneSixLibrary::files()
 {
+	QStringList retval;
 	QString storage = storagePath();
 	if (storage.contains("${arch}"))
 	{
 		QString cooked_storage = storage;
 		cooked_storage.replace("${arch}", "32");
-		QFileInfo info32(PathCombine("libraries", cooked_storage));
-		if (!info32.exists())
-		{
-			return false;
-		}
+		retval.append(PathCombine("libraries", cooked_storage));
 		cooked_storage = storage;
 		cooked_storage.replace("${arch}", "64");
-		QFileInfo info64(PathCombine("libraries", cooked_storage));
-		if (!info64.exists())
-		{
-			return false;
-		}
+		retval.append(PathCombine("libraries", cooked_storage));
 	}
 	else
+		retval.append(PathCombine("libraries", storage));
+	return retval;
+}
+
+bool OneSixLibrary::filesExist()
+{
+	auto libFiles = files();
+	for(auto file: libFiles)
 	{
-		QFileInfo info(PathCombine("libraries", storage));
+		QFileInfo info(file);
 		if (!info.exists())
-		{
 			return false;
-		}
 	}
 	return true;
 }

logic/OneSixLibrary.h

@@ -143,4 +143,5 @@ public:
 
 	bool extractTo(QString target_dir);
 	bool filesExist();
+	QStringList files();
 };

logic/OneSixUpdate.cpp

@@ -268,10 +268,16 @@ void OneSixUpdate::jarlibStart()
 
 	auto metacache = MMC->metacache();
 	QList<ForgeXzDownloadPtr> ForgeLibs;
+	QList<std::shared_ptr<OneSixLibrary>> brokenLocalLibs;
+
 	for (auto lib : libs)
 	{
 		if (lib->hint() == "local")
+		{
+			if(!lib->filesExist())
+				brokenLocalLibs.append(lib);
 			continue;
+		}
 
 		QString raw_storage = lib->storagePath();
 		QString raw_dl = lib->downloadUrl();
@@ -305,6 +311,18 @@ void OneSixUpdate::jarlibStart()
 			f(raw_storage, raw_dl);
 		}
 	}
+	if(!brokenLocalLibs.empty())
+	{
+		jarlibDownloadJob.reset();
+		QStringList failed;
+		for(auto brokenLib : brokenLocalLibs)
+		{
+			failed.append(brokenLib->files());
+		}
+		QString failed_all = failed.join("\n");
+		emitFailed(tr("Some libraries marked as 'local' are missing their jar files:\n%1\n\nYou'll have to correct this problem manually. If this is an externally tracked instance, make sure to run it at least once outside of MultiMC.").arg(failed_all));
+		return;
+	}
 	// TODO: think about how to propagate this from the original json file... or IF AT ALL
 	QString forgeMirrorList = "http://files.minecraftforge.net/mirror-brand.list";
 	if (!ForgeLibs.empty())