If the system environment variables include kafka or KAFKA, the KafkaRuntimeConfigProducer throws an exception.

[shellj]

Describe the bug

If the system environment variables include kafka or KAFKA, the KafkaRuntimeConfigProducer throws an error.

Caused by: java.lang.StringIndexOutOfBoundsException: Range [6, 5) out of bounds for length 5
	at java.base/jdk.internal.util.Preconditions$1.apply(Preconditions.java:55)
	at java.base/jdk.internal.util.Preconditions$1.apply(Preconditions.java:52)
	at java.base/jdk.internal.util.Preconditions$4.apply(Preconditions.java:213)
	at java.base/jdk.internal.util.Preconditions$4.apply(Preconditions.java:210)
	at java.base/jdk.internal.util.Preconditions.outOfBounds(Preconditions.java:98)
	at java.base/jdk.internal.util.Preconditions.outOfBoundsCheckFromToIndex(Preconditions.java:112)
	at java.base/jdk.internal.util.Preconditions.checkFromToIndex(Preconditions.java:349)
	at java.base/java.lang.String.checkBoundsBeginEnd(String.java:4861)
	at java.base/java.lang.String.substring(String.java:2830)
	at java.base/java.lang.String.substring(String.java:2803)
	at io.quarkus.kafka.client.runtime.KafkaRuntimeConfigProducer.createKafkaRuntimeConfig(KafkaRuntimeConfigProducer.java:40)
	at io.quarkus.kafka.client.runtime.KafkaRuntimeConfigProducer_ProducerMethod_createKafkaRuntimeConfig_VzcC8CdA4ZIN2S227pAbEVHVF_c_Bean.doCreate(Unknown Source)
	at io.quarkus.kafka.client.runtime.KafkaRuntimeConfigProducer_ProducerMethod_createKafkaRuntimeConfig_VzcC8CdA4ZIN2S227pAbEVHVF_c_Bean.create(Unknown Source)
	at io.quarkus.kafka.client.runtime.KafkaRuntimeConfigProducer_ProducerMethod_createKafkaRuntimeConfig_VzcC8CdA4ZIN2S227pAbEVHVF_c_Bean.create(Unknown Source)
	at io.quarkus.arc.impl.AbstractSharedContext.createInstanceHandle(AbstractSharedContext.java:119)

The substring here throws an exception:

quarkus/extensions/kafka-client/runtime/src/main/java/io/quarkus/kafka/client/runtime/KafkaRuntimeConfigProducer.java

Lines 40 to 41 in 670b1ad

	String effectivePropertyName = propertyNameLowerCase.substring(CONFIG_PREFIX.length() + 1).toLowerCase()
	.replace("_", ".");

Expected behavior

Work without throwing any error

Actual behavior

throw exception: Caused by: java.lang.StringIndexOutOfBoundsException: Range [6, 5) out of bounds for length 5

How to Reproduce?

1. Configuring the system environment variable KAFKA=xxx.xxx.xxx.xxx:9092.
2. Start the kafka application

Output of uname -a or ver

Windows_NT minij 6.2 9200 x86_64 MS/Windows

Output of java -version

openjdk version "21" 2023-09-19 OpenJDK Runtime Environment (build 21+35-2513) OpenJDK 64-Bit Server VM (build 21+35-2513, mixed mode, sharing)

Quarkus version or git rev

3.10.1

Build tool (ie. output of mvnw --version or gradlew --version)

Apache Maven 3.9.1 (2e178502fcdbffc201671fb2537d0cb4b4cc58f8)

Additional information

No response

[quarkus-bot]

/cc @alesj (kafka), @cescoffier (kafka), @ozangunalp (kafka), @radcortez (config)

[gsmet]

@shellj thanks for the detailed report. Does #40741 make sense for you?

[shellj]

@shellj thanks for the detailed report. Does #40741 make sense for you?

Yes, that's perfect