NOISSUE prevent -version being passed to the JRE

We want specific JREs, always, not something that is magically resolved.
This counteracts some really bad advice recently being spread on reddit.

Author: peterix

launcher/JavaCommon.cpp

@@ -17,6 +17,17 @@ bool JavaCommon::checkJVMArgs(QString jvmargs, QWidget *parent)
             QMessageBox::Warning)->exec();
         return false;
     }
+    // block lunacy with passing required version to the JVM
+    if (jvmargs.contains(QRegExp("-version:.*"))) {
+        auto warnStr = QObject::tr(
+            "You tried to pass required java version argument to the JVM (using \"-version=xxx\"). This is not safe and will not be allowed.\n"
+            "This message will be displayed until you remove this from the JVM arguments.");
+        CustomMessageBox::selectable(
+            parent, QObject::tr("JVM arguments warning"),
+            warnStr,
+            QMessageBox::Warning)->exec();
+        return false;
+    }
     return true;
 }
 

launcher/LaunchController.cpp

@@ -36,7 +36,10 @@ void LaunchController::executeTask()
         return;
     }
 
-    JavaCommon::checkJVMArgs(m_instance->settings()->get("JvmArgs").toString(), m_parentWidget);
+    if(!JavaCommon::checkJVMArgs(m_instance->settings()->get("JvmArgs").toString(), m_parentWidget)) {
+        emitFailed(tr("Invalid Java arguments specified. Please fix this first."));
+        return;
+    }
 
     login();
 }

launcher/ui/pages/instance/InstanceSettingsPage.cpp

@@ -141,7 +141,6 @@ void InstanceSettingsPage::applySettings()
     if(javaArgs)
     {
         m_settings->set("JvmArgs", ui->jvmArgsTextBox->toPlainText().replace("\n", " "));
-        JavaCommon::checkJVMArgs(m_settings->get("JvmArgs").toString(), this->parentWidget());
     }
     else
     {