8312984: javac may crash on a record pattern with too few components

Backport-of: c3860917346fb53ed3d23f11d112b58b8cd8448a

Author: lahodaj

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java

@@ -3480,7 +3480,9 @@ public PatternDescription makePatternDescription(Type selectorType, JCPattern pa
             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) {

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

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 @@ void errorRecoveryNoPattern1(Object o) {
             case Object obj: break;
         }
     }
+    int errorRecoveryNoPattern2(Object o) {
+        return switch(o) {
+            case R(var v, ) -> 1;
+            default -> -1;
+        };
+    }
+
+    record R(String x) {}
 }

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