Add error message when setting config to existing value

src/Console/Config.php

@@ -128,6 +128,10 @@ HELP;
 				throw new RuntimeException("$cat.$key is an array and can't be set using this command.");
 			}
 
+			if ($this->config->get($cat, $key) == $value) {
+				throw new RuntimeException("$cat.$key already set to $value.");
+			}
+
 			$result = $this->config->set($cat, $key, $value);
 			if ($result) {
 				$this->out("{$cat}.{$key} <= " .

tests/src/Console/ConfigConsoleTest.php

@@ -65,8 +65,13 @@ class ConfigConsoleTest extends ConsoleTest
 		$this->configMock
 			->shouldReceive('get')
 			->with('config', 'test')
-			->andReturn('now')
+			->andReturn('old')
 			->twice();
+		$this->configMock
+			->shouldReceive('get')
+			->with('config', 'test')
+			->andReturn('now')
+			->once();
 
 		$console = new Config($this->appMode, $this->configMock, $this->consoleArgv);
 		$console->setArgument(0, 'config');
@@ -118,6 +123,23 @@ class ConfigConsoleTest extends ConsoleTest
 		self::assertEquals("[Error] config.test is an array and can't be set using this command.\n", $txt);
 	}
 
+	public function testSetExistingValue()
+	{
+		$this->configMock
+			->shouldReceive('get')
+			->with('config', 'test')
+			->andReturn('now')
+			->twice();
+
+		$console = new Config($this->appMode, $this->configMock, $this->consoleArgv);
+		$console->setArgument(0, 'config');
+		$console->setArgument(1, 'test');
+		$console->setArgument(2, 'now');
+		$txt = $this->dumpExecute($console);
+
+		self::assertEquals("[Error] config.test already set to now.\n", $txt);
+	}
+
 	public function testTooManyArguments()
 	{
 		$console = new Config($this->appMode, $this->configMock, $this->consoleArgv);
@@ -171,7 +193,7 @@ CONF;
 			->shouldReceive('get')
 			->with('test', 'it')
 			->andReturn(null)
-			->once();
+			->twice();
 		$console = new Config($this->appMode, $this->configMock, [$this->consoleArgv]);
 		$console->setArgument(0, 'test');
 		$console->setArgument(1, 'it');