Bug 544702 - [12] unexpected fall-through in switch statement withY20190225-0415

switch-labeled-rule

2 files changed, 49 insertions, 0 deletions

diff --git a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SwitchExpressionTest.java b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SwitchExpressionTest.java
index 512af7f814..9dc36ff9ca 100644
--- a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SwitchExpressionTest.java
+++ b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/SwitchExpressionTest.java
@@ -2130,4 +2130,28 @@ public class SwitchExpressionTest extends AbstractRegressionTest {
 		null,
 		new String[] {"--enable-preview"});
 	}
+	public void testBug544702_01() {
+		runConformTest(
+			new String[] {
+				"X.java",
+				"public class X {\n" +
+				"    @SuppressWarnings(\"preview\")\n" +
+				"	public int foo(int i) {\n" +
+				"    	int k = 10;\n" +
+				"    	switch (i) {\n" +
+				"    		case 0 -> { k = 0;}\n" +
+				"    		default -> k = -1;\n" +
+				"    	}\n" +
+				"        return k;\n" +
+				"    }\n" +
+				"    public static void main(String[] argv) {\n" +
+				"        System.out.println(new X().foo(0) == 0 ? \"Success\" : \"Failure\");\n" +
+				"    }\n" +
+				"\n" +
+				"}\n"
+		},
+		"Success",
+		null,
+		new String[] {"--enable-preview"});
+	}
 }
\ No newline at end of file
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/SwitchStatement.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/SwitchStatement.java
index adb1c90c0d..0f49d12bf4 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/SwitchStatement.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/SwitchStatement.java
@@ -84,6 +84,31 @@ public class SwitchStatement extends Expression {
 	private LocalVariableBinding dispatchStringCopy = null;
 
 	protected int getFallThroughState(Statement stmt, BlockScope blockScope) {
+		if (this.switchLabeledRules) {
+			if (stmt instanceof Expression || stmt instanceof ThrowStatement)
+				return BREAKING;
+			
+			if (stmt instanceof Block) {
+				Block block = (Block) stmt;
+				if (block.doesNotCompleteNormally()) {
+					return BREAKING;
+				}
+				// else add an implicit break
+				BreakStatement breakStatement = new BreakStatement(null, block.sourceEnd -1, block.sourceEnd);
+				breakStatement.isImplicit = true;
+
+				int l = block.statements == null ? 0 : block.statements.length;
+				if (l == 0) {
+					block.statements = new Statement[] {breakStatement};
+				} else {
+					Statement[] newArray = new Statement[l + 1];
+					System.arraycopy(block.statements, 0, newArray, 0, l);
+					newArray[l] = breakStatement;
+					block.statements = newArray;
+				}
+				return BREAKING;
+			}
+		}
 		return FALLTHROUGH;
 	}
 	protected void completeNormallyCheck(BlockScope blockScope) {