From c3860917346fb53ed3d23f11d112b58b8cd8448a Mon Sep 17 00:00:00 2001
From: Jan Lahoda <jlahoda@openjdk.org>
Date: Thu, 3 Aug 2023 08:37:15 +0000
Subject: [PATCH] 8312984: javac may crash on a record pattern with too few
 components

Reviewed-by: vromero
---
 .../share/classes/com/sun/tools/javac/comp/Flow.java |  4 +++-
 .../javac/patterns/PatternErrorRecovery-old.out      |  4 +++-
 .../tools/javac/patterns/PatternErrorRecovery.java   | 12 ++++++++++--
 .../tools/javac/patterns/PatternErrorRecovery.out    |  4 +++-
 4 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java
index d897dc3ef24..2fe5183bb11 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java
@@ -3480,7 +3480,9 @@ public class Flow {
             for (List<JCPattern> it = record.nested;
                  it.nonEmpty();
                  it = it.tail, i++) {
-                nestedDescriptions[i] = makePatternDescription(types.erasure(componentTypes[i]), it.head);
+                Type componentType = i < componentTypes.length ? componentTypes[i]
+                                                               : syms.errType;
+                nestedDescriptions[i] = makePatternDescription(types.erasure(componentType), it.head);
             }
             return new RecordPattern(record.type, componentTypes, nestedDescriptions);
         } else if (pattern instanceof JCAnyPattern) {
diff --git a/test/langtools/tools/javac/patterns/PatternErrorRecovery-old.out b/test/langtools/tools/javac/patterns/PatternErrorRecovery-old.out
index 6a149913c02..3b8f5d1b115 100644
--- a/test/langtools/tools/javac/patterns/PatternErrorRecovery-old.out
+++ b/test/langtools/tools/javac/patterns/PatternErrorRecovery-old.out
@@ -1,3 +1,5 @@
 PatternErrorRecovery.java:12:18: compiler.err.feature.not.supported.in.source.plural: (compiler.misc.feature.pattern.switch), 20, 21
+PatternErrorRecovery.java:17:19: compiler.err.feature.not.supported.in.source.plural: (compiler.misc.feature.deconstruction.patterns), 20, 21
+PatternErrorRecovery.java:17:27: compiler.err.illegal.start.of.type
 PatternErrorRecovery.java:11:18: compiler.err.pattern.expected
-2 errors
+4 errors
diff --git a/test/langtools/tools/javac/patterns/PatternErrorRecovery.java b/test/langtools/tools/javac/patterns/PatternErrorRecovery.java
index 2e73de015b3..d281fcc00a7 100644
--- a/test/langtools/tools/javac/patterns/PatternErrorRecovery.java
+++ b/test/langtools/tools/javac/patterns/PatternErrorRecovery.java
@@ -1,8 +1,8 @@
 /*
  * @test /nodynamiccopyright/
- * @bug 8268320
+ * @bug 8268320 8312984
  * @summary Verify user-friendly errors are reported for ill-formed pattern.
- * @compile/fail/ref=PatternErrorRecovery.out -XDrawDiagnostics -XDshould-stop.at=FLOW PatternErrorRecovery.java
+ * @compile/fail/ref=PatternErrorRecovery.out -XDrawDiagnostics -XDshould-stop.at=FLOW -XDdev PatternErrorRecovery.java
  * @compile/fail/ref=PatternErrorRecovery-old.out --release 20 -XDrawDiagnostics -XDshould-stop.at=FLOW PatternErrorRecovery.java
  */
 public class PatternErrorRecovery {
@@ -12,4 +12,12 @@ public class PatternErrorRecovery {
             case Object obj: break;
         }
     }
+    int errorRecoveryNoPattern2(Object o) {
+        return switch(o) {
+            case R(var v, ) -> 1;
+            default -> -1;
+        };
+    }
+
+    record R(String x) {}
 }
diff --git a/test/langtools/tools/javac/patterns/PatternErrorRecovery.out b/test/langtools/tools/javac/patterns/PatternErrorRecovery.out
index 13cc0faf70c..65a20619b1d 100644
--- a/test/langtools/tools/javac/patterns/PatternErrorRecovery.out
+++ b/test/langtools/tools/javac/patterns/PatternErrorRecovery.out
@@ -1,2 +1,4 @@
+PatternErrorRecovery.java:17:27: compiler.err.illegal.start.of.type
 PatternErrorRecovery.java:11:18: compiler.err.pattern.expected
-1 error
+PatternErrorRecovery.java:17:18: compiler.err.incorrect.number.of.nested.patterns: java.lang.String, java.lang.String,<any>
+3 errors