Fix redundant error message when calling unavailable commands

Resolves #1387

Author: fmbenhassine

spring-shell-core/src/main/java/org/springframework/shell/core/InteractiveShellRunner.java

@@ -125,7 +125,10 @@ private void doRun() {
 				CommandContext commandContext = new CommandContext(parsedInput, this.commandRegistry, getWriter(),
 						getReader());
 				ExitStatus exitStatus = this.commandExecutor.execute(commandContext);
-				if (ExitStatus.OK.code() != exitStatus.code()) { // business error
+				boolean businessError = ExitStatus.OK.code() != exitStatus.code();
+				// the command itself already prints a dedicated availability message
+				boolean alreadyReported = ExitStatus.AVAILABILITY_ERROR.code() == exitStatus.code();
+				if (businessError && !alreadyReported) {
 					print("Error while executing command " + parsedInput.commandName() + ": "
 							+ exitStatus.description());
 				}

spring-shell-core/src/test/java/org/springframework/shell/core/InteractiveShellRunnerTests.java

@@ -0,0 +1,99 @@
+/*
+ * Copyright 2026-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.shell.core;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.shell.core.command.AbstractCommand;
+import org.springframework.shell.core.command.Command;
+import org.springframework.shell.core.command.CommandContext;
+import org.springframework.shell.core.command.CommandParser;
+import org.springframework.shell.core.command.CommandRegistry;
+import org.springframework.shell.core.command.ExitStatus;
+import org.springframework.shell.core.command.ParsedInput;
+import org.springframework.shell.core.command.availability.Availability;
+import org.springframework.shell.core.command.availability.AvailabilityProvider;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link InteractiveShellRunner}.
+ *
+ * @author Mahmoud Ben Hassine
+ */
+class InteractiveShellRunnerTests {
+
+	@Test
+	void testUnavailableCommandDoesNotAlsoPrintGenericErrorMessage() throws Exception {
+		// given
+		Command command = new AbstractCommand("test", "A test command") {
+
+			@Override
+			public AvailabilityProvider getAvailabilityProvider() {
+				return AvailabilityProvider.of(Availability.unavailable("you are not logged in"));
+			}
+
+			@Override
+			public ExitStatus doExecute(CommandContext commandContext) {
+				return ExitStatus.OK;
+			}
+		};
+		CommandRegistry commandRegistry = new CommandRegistry(Set.of(command));
+		CommandParser commandParser = input -> ParsedInput.builder().commandName(input).build();
+		List<String> lines = new ArrayList<>(List.of("test"));
+		InputProvider inputProvider = () -> lines.isEmpty() ? null : lines.remove(0);
+		StringWriter outputWriter = new StringWriter();
+		List<String> printedMessages = new ArrayList<>();
+		InteractiveShellRunner shellRunner = new InteractiveShellRunner(inputProvider, commandParser, commandRegistry) {
+
+			@Override
+			public void print(String message) {
+				printedMessages.add(message);
+			}
+
+			@Override
+			public void flush() {
+			}
+
+			@Override
+			public PrintWriter getWriter() {
+				return new PrintWriter(outputWriter);
+			}
+
+			@Override
+			public InputReader getReader() {
+				return mock(InputReader.class);
+			}
+		};
+
+		// when
+		shellRunner.run(new String[0]);
+
+		// then
+		assertEquals("Command 'test' exists but is not currently available because you are not logged in",
+				outputWriter.toString().trim());
+		assertFalse(printedMessages.stream().anyMatch(message -> message.startsWith("Error while executing command")));
+	}
+
+}