From df19da0dde96ed63d338da1a3aefa7c36f8645d9 Mon Sep 17 00:00:00 2001
From: Janne Valkealahti <janne.valkealahti@gmail.com>
Date: Tue, 22 Nov 2022 07:47:52 +0000
Subject: [PATCH] Method execution should not error without value

- Do npe check when getting class type out from
  incoming value.
- Backport #572
- Fix #573
---
 .../shell/command/CommandExecution.java       |  4 +++-
 .../shell/command/CommandExecutionTests.java  | 20 +++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/spring-shell-core/src/main/java/org/springframework/shell/command/CommandExecution.java b/spring-shell-core/src/main/java/org/springframework/shell/command/CommandExecution.java
index 3c742e87..b1b74c5b 100644
--- a/spring-shell-core/src/main/java/org/springframework/shell/command/CommandExecution.java
+++ b/spring-shell-core/src/main/java/org/springframework/shell/command/CommandExecution.java
@@ -183,8 +183,10 @@ public interface CommandExecution {
 			if (parameterName == null) {
 				return false;
 			}
+			Class<?> sourceType = paramValues.get(parameterName) != null ? paramValues.get(parameterName).getClass()
+					: null;
 			return paramValues.containsKey(parameterName) && conversionService
-					.canConvert(paramValues.get(parameterName).getClass(), parameter.getParameterType());
+					.canConvert(sourceType, parameter.getParameterType());
 		}
 
 		@Override
diff --git a/spring-shell-core/src/test/java/org/springframework/shell/command/CommandExecutionTests.java b/spring-shell-core/src/test/java/org/springframework/shell/command/CommandExecutionTests.java
index 1ef21d22..d801bac0 100644
--- a/spring-shell-core/src/test/java/org/springframework/shell/command/CommandExecutionTests.java
+++ b/spring-shell-core/src/test/java/org/springframework/shell/command/CommandExecutionTests.java
@@ -100,6 +100,26 @@ public class CommandExecutionTests extends AbstractCommandTests {
 		assertThat(pojo1.method1Ctx).isNotNull();
 	}
 
+	@Test
+	public void testMethodArgWithoutValue() {
+		CommandRegistration r1 = CommandRegistration.builder()
+			.command("command1")
+			.description("help")
+			.withOption()
+				.longNames("arg1")
+				.description("some arg1")
+				.position(0)
+				.arity(OptionArity.EXACTLY_ONE)
+				.and()
+			.withTarget()
+				.method(pojo1, "method4")
+				.and()
+			.build();
+		execution.evaluate(r1, new String[]{"--arg1"});
+		assertThat(pojo1.method4Count).isEqualTo(1);
+		assertThat(pojo1.method4Arg1).isNull();
+	}
+
 	@Test
 	public void testMethodSinglePositionalArgs() {
 		CommandRegistration r1 = CommandRegistration.builder()