From fea1464562289c64b1bfe858f74d50970531a8a0 Mon Sep 17 00:00:00 2001
From: Sam Brannen <104798+sbrannen@users.noreply.github.com>
Date: Fri, 8 Mar 2024 15:29:42 +0100
Subject: [PATCH 1/2] Ensure SpEL can compile an expression indexing into a
 boolean array

Closes gh-32400
---
 .../springframework/expression/spel/ast/Indexer.java |  6 ++++++
 .../spel/SpelCompilationCoverageTests.java           | 12 ++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/spring-expression/src/main/java/org/springframework/expression/spel/ast/Indexer.java b/spring-expression/src/main/java/org/springframework/expression/spel/ast/Indexer.java
index b1fbc3225a..e0bc8be533 100644
--- a/spring-expression/src/main/java/org/springframework/expression/spel/ast/Indexer.java
+++ b/spring-expression/src/main/java/org/springframework/expression/spel/ast/Indexer.java
@@ -245,6 +245,12 @@ public class Indexer extends SpelNodeImpl {
 				}
 				case "B" -> {
 					mv.visitTypeInsn(CHECKCAST, "[B");
+					// byte and boolean arrays are both loaded via BALOAD
+					yield BALOAD;
+				}
+				case "Z" -> {
+					mv.visitTypeInsn(CHECKCAST, "[Z");
+					// byte and boolean arrays are both loaded via BALOAD
 					yield BALOAD;
 				}
 				case "C" -> {
diff --git a/spring-expression/src/test/java/org/springframework/expression/spel/SpelCompilationCoverageTests.java b/spring-expression/src/test/java/org/springframework/expression/spel/SpelCompilationCoverageTests.java
index 33e8604732..41c22b88a3 100644
--- a/spring-expression/src/test/java/org/springframework/expression/spel/SpelCompilationCoverageTests.java
+++ b/spring-expression/src/test/java/org/springframework/expression/spel/SpelCompilationCoverageTests.java
@@ -308,6 +308,18 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 			assertThat(getAst().getExitDescriptor()).isEqualTo("C");
 		}
 
+		@Test
+		void indexIntoPrimitiveBooleanArray() {
+			boolean[] booleans = { true, false };
+
+			expression = parser.parseExpression("[1]");
+
+			assertThat(expression.getValue(booleans)).isEqualTo(false);
+			assertCanCompile(expression);
+			assertThat(expression.getValue(booleans)).isEqualTo(false);
+			assertThat(getAst().getExitDescriptor()).isEqualTo("Z");
+		}
+
 		@Test
 		void indexIntoStringArray() {
 			String[] strings = { "a", "b", "c" };

From 528029a0ba4f651e9bc9799d2cfab02b2689643e Mon Sep 17 00:00:00 2001
From: Sam Brannen <104798+sbrannen@users.noreply.github.com>
Date: Fri, 8 Mar 2024 15:47:10 +0100
Subject: [PATCH 2/2] Document that SpEL expressions using array construction
 cannot be compiled

Closes gh-32401
---
 .../ROOT/pages/core/expressions/evaluation.adoc  |  1 +
 .../language-ref/array-construction.adoc         | 16 ++++++++++++----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/framework-docs/modules/ROOT/pages/core/expressions/evaluation.adoc b/framework-docs/modules/ROOT/pages/core/expressions/evaluation.adoc
index 43840d17d2..9c9f6953f6 100644
--- a/framework-docs/modules/ROOT/pages/core/expressions/evaluation.adoc
+++ b/framework-docs/modules/ROOT/pages/core/expressions/evaluation.adoc
@@ -518,6 +518,7 @@ following kinds of expressions cannot be compiled.
 * Expressions relying on the conversion service
 * Expressions using custom resolvers or accessors
 * Expressions using overloaded operators
+* Expressions using array construction syntax
 * Expressions using selection or projection
 
 Compilation of additional kinds of expressions may be supported in the future.
diff --git a/framework-docs/modules/ROOT/pages/core/expressions/language-ref/array-construction.adoc b/framework-docs/modules/ROOT/pages/core/expressions/language-ref/array-construction.adoc
index 01e181ae30..4bc9317422 100644
--- a/framework-docs/modules/ROOT/pages/core/expressions/language-ref/array-construction.adoc
+++ b/framework-docs/modules/ROOT/pages/core/expressions/language-ref/array-construction.adoc
@@ -13,7 +13,7 @@ Java::
 	int[] numbers1 = (int[]) parser.parseExpression("new int[4]").getValue(context);
 
 	// Array with initializer
-	int[] numbers2 = (int[]) parser.parseExpression("new int[]{1,2,3}").getValue(context);
+	int[] numbers2 = (int[]) parser.parseExpression("new int[] {1, 2, 3}").getValue(context);
 
 	// Multi dimensional array
 	int[][] numbers3 = (int[][]) parser.parseExpression("new int[4][5]").getValue(context);
@@ -26,14 +26,22 @@ Kotlin::
 	val numbers1 = parser.parseExpression("new int[4]").getValue(context) as IntArray
 
 	// Array with initializer
-	val numbers2 = parser.parseExpression("new int[]{1,2,3}").getValue(context) as IntArray
+	val numbers2 = parser.parseExpression("new int[] {1, 2, 3}").getValue(context) as IntArray
 
 	// Multi dimensional array
 	val numbers3 = parser.parseExpression("new int[4][5]").getValue(context) as Array<IntArray>
 ----
 ======
 
+[NOTE]
+====
 You cannot currently supply an initializer when you construct a multi-dimensional array.
+====
 
-
-
+[CAUTION]
+====
+Any expression that constructs an array – for example, via `new int[4]` or
+`new int[] {1, 2, 3}` – cannot be compiled. See
+xref:core/expressions/evaluation.adoc#expressions-compiler-limitations[Compiler Limitations]
+for details.
+====