postfixCompletion proposal computer did not complete normally

[Madjosz]

When having "Java Postfix Template Proposals" enabled, with the following code

class MyClass {
    MyClass(Object o) {
    }
}

and the caret between ( and Object of the MyClass constructor, when activating Content Assist the following exception is thrown:

The 'org.eclipse.jdt.ui.postfixCompletion' proposal computer from the 'org.eclipse.jdt.ui' plug-in did not complete normally. The extension has thrown a runtime exception.

java.lang.IllegalArgumentException: 
    at org.eclipse.jdt.core.Signature.createCharArrayTypeSignature(Signature.java:1105)
    at org.eclipse.jdt.core.Signature.createTypeSignature(Signature.java:1305)
    at org.eclipse.jdt.internal.core.CompilationUnitStructureRequestor.convertTypeNamesToSigs(CompilationUnitStructureRequestor.java:292)
    at org.eclipse.jdt.internal.codeassist.CompletionUnitStructureRequestor.createMethodHandle(CompletionUnitStructureRequestor.java:143)
    at org.eclipse.jdt.internal.core.CompilationUnitStructureRequestor.enterMethod(CompilationUnitStructureRequestor.java:419)
    at org.eclipse.jdt.internal.core.CompilationUnitStructureRequestor.enterConstructor(CompilationUnitStructureRequestor.java:345)
    at org.eclipse.jdt.internal.compiler.SourceElementNotifier.notifySourceElementRequestor(SourceElementNotifier.java:334)
    at org.eclipse.jdt.internal.codeassist.CompletionElementNotifier.notifySourceElementRequestor(CompletionElementNotifier.java:197)
    at org.eclipse.jdt.internal.compiler.SourceElementNotifier.notifySourceElementRequestor(SourceElementNotifier.java:804)
    at org.eclipse.jdt.internal.codeassist.CompletionElementNotifier.notifySourceElementRequestor(CompletionElementNotifier.java:226)
    at org.eclipse.jdt.internal.compiler.SourceElementNotifier.notifySourceElementRequestor(SourceElementNotifier.java:488)
    at org.eclipse.jdt.internal.codeassist.CompletionElementNotifier.notifySourceElementRequestor(CompletionElementNotifier.java:202)
    at org.eclipse.jdt.internal.codeassist.InternalExtendedCompletionContext.computeEnclosingJavaElements(InternalExtendedCompletionContext.java:162)
    at org.eclipse.jdt.internal.codeassist.InternalExtendedCompletionContext.getEnclosingElement(InternalExtendedCompletionContext.java:255)
    at org.eclipse.jdt.internal.codeassist.InternalCompletionContext.getEnclosingElement(InternalCompletionContext.java:128)
    at org.eclipse.jdt.internal.ui.text.java.PostfixCompletionProposalComputer.updateTemplateEngine(PostfixCompletionProposalComputer.java:142)
    at org.eclipse.jdt.internal.ui.text.java.PostfixCompletionProposalComputer.analyzeCoreContext(PostfixCompletionProposalComputer.java:121)
    at org.eclipse.jdt.internal.ui.text.java.PostfixCompletionProposalComputer.computeCompletionEngine(PostfixCompletionProposalComputer.java:110)
    at org.eclipse.jdt.internal.ui.text.java.AbstractTemplateCompletionProposalComputer.computeCompletionProposals(AbstractTemplateCompletionProposalComputer.java:71)
    at org.eclipse.jdt.internal.ui.text.java.CompletionProposalComputerDescriptor.computeCompletionProposals(CompletionProposalComputerDescriptor.java:348)
    at org.eclipse.jdt.internal.ui.text.java.CompletionProposalCategory.computeCompletionProposals(CompletionProposalCategory.java:340)
    at org.eclipse.jdt.internal.ui.text.java.ContentAssistProcessor.collectProposals(ContentAssistProcessor.java:333)
    at org.eclipse.jdt.internal.ui.text.java.ContentAssistProcessor.computeCompletionProposals(ContentAssistProcessor.java:289)
    at org.eclipse.jface.text.contentassist.AsyncCompletionProposalPopup.lambda$10(AsyncCompletionProposalPopup.java:378)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:47)
    at org.eclipse.jface.text.contentassist.AsyncCompletionProposalPopup.lambda$9(AsyncCompletionProposalPopup.java:377)
    at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1768)
    at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.exec(CompletableFuture.java:1760)
    at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
    at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
    at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
    at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
    at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)

System information

Eclipse SDK Version: 2024-03 (4.31) Build id: I20231212-0120

openjdk version "21" 2023-09-19 LTS OpenJDK Runtime Environment Temurin-21+35 (build 21+35-LTS) OpenJDK 64-Bit Server VM Temurin-21+35 (build 21+35-LTS, mixed mode, sharing)

[jukzi]

can reproduce