client: allow setting system properties via runtime config

runelite-client/src/main/java/net/runelite/client/RuneLite.java

@@ -44,6 +44,7 @@ import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
 import java.security.cert.X509Certificate;
 import java.util.Locale;
+import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Stream;
 import javax.annotation.Nullable;
@@ -145,6 +146,10 @@ public class RuneLite
 	@Nullable
 	private Client client;
 
+	@Inject
+	@Nullable
+	private RuntimeConfig runtimeConfig;
+
 	public static void main(String[] args) throws Exception
 	{
 		Locale.setDefault(Locale.ENGLISH);
@@ -287,6 +292,8 @@ public class RuneLite
 			injector.injectMembers(client);
 		}
 
+		setupSystemProps();
+
 		// Start the applet
 		if (applet != null)
 		{
@@ -514,4 +521,19 @@ public class RuneLite
 			log.warn("unable to copy jagexcache", e);
 		}
 	}
+
+	private void setupSystemProps()
+	{
+		if (runtimeConfig == null || runtimeConfig.getSysProps() == null)
+		{
+			return;
+		}
+
+		for (Map.Entry<String, String> entry : runtimeConfig.getSysProps().entrySet())
+		{
+			String key = entry.getKey(), value = entry.getValue();
+			log.debug("Setting property {}={}", key, value);
+			System.setProperty(key, value);
+		}
+	}
 }

runelite-client/src/main/java/net/runelite/client/RuntimeConfig.java

@@ -32,4 +32,5 @@ import lombok.Data;
 public class RuntimeConfig
 {
 	private Map<String, ?> props = Collections.emptyMap();
+	private Map<String, String> sysProps = Collections.emptyMap();
 }