Test properties containing a double-quote alone with q/dev/io.quarkus…

….quarkus-vertx-http/config

In particular the environment variable `__INTELLIJ_COMMAND_HISTFILE__`,
translated to `%.intellij.command.histfile.`, seems to be giving that
page a hard time.

extensions/vertx-http/deployment/src/test/java/io/quarkus/vertx/http/devconsole/DevConsoleConfigMisinterpretedDoubleUnderscoreTest.java

@@ -0,0 +1,32 @@
+package io.quarkus.vertx.http.devconsole;
+
+import org.hamcrest.Matchers;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.test.QuarkusDevModeTest;
+import io.restassured.RestAssured;
+
+/**
+ * Tests that a system property such as {@code %.intellij.command.histfile."}
+ * doesn't lead to an exception because {@code "} is incorrectly seen as a quoted property.
+ * <p>
+ * Originally the bug stemmed from an environment property {@code __INTELLIJ_COMMAND_HISTFILE__}
+ * which was (weirdly) interpreted as {@code %.intellij.command.histfile."},
+ * but it's much easier to test system properties (which are mutable)
+ * than environment properties.
+ */
+public class DevConsoleConfigMisinterpretedDoubleUnderscoreTest {
+
+    @RegisterExtension
+    static final QuarkusDevModeTest config = new QuarkusDevModeTest()
+            .setBuildSystemProperty("%.intellij.command.histfile.\"", "foo")
+            .withEmptyApplication();
+
+    @Test
+    public void testNoFailure() {
+        RestAssured.get("q/dev/io.quarkus.quarkus-vertx-http/config")
+                .then()
+                .statusCode(200).body(Matchers.containsString("Config Editor"));
+    }
+}