Fix NPE in currentNameMatch/nextNameMatch when PropertyNameMatcher is null [databind#5811]

[Copilot]

When ObjectMapper.convertValue() is used with a custom deserializer wrapping a BeanDeserializer, the inner deserializer's _nameMatcher can be null at deserialization time, causing an NPE when BeanDeserializer passes it to p.currentNameMatch(null).

Changes

• ParserMinimalBase — null-guard in both currentNameMatch() and nextNameMatch(): return MATCH_UNKNOWN_NAME when matcher == null and current token is PROPERTY_NAME, allowing callers to fall back to slow-path string-based matching
• UTF8StreamJsonParser — null-guard in the optimized nextNameMatch(): skip quad-based fast path, parse name normally, return MATCH_UNKNOWN_NAME
• JsonParserSequence / FilteringParserDelegate — same null-guard in their nextNameMatch() overrides
• NextNameWithMatcherTest — added @Test annotations (existing tests were not being discovered by JUnit 5), added testNullMatcherNextNameMatch and testNullMatcherCurrentNameMatch covering all parser modes

Behavior when matcher is null

Current token	Return value
PROPERTY_NAME	MATCH_UNKNOWN_NAME
END_OBJECT	MATCH_END_OBJECT
anything else	MATCH_ODD_TOKEN

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• central.sonatype.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --enable-native-access=ALL-UNNAMED -classpath /usr/share/apache-maven-3.9.13/boot/plexus-classworlds-2.9.0.jar -Dclassworlds.conf=/usr/share/apache-maven-3.9.13/bin/m2.conf -Dmaven.home=/usr/share/apache-maven-3.9.13 -Dlibrary.jansi.path=/usr/share/apache-maven-3.9.13/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/jackson-core/jackson-core org.codehaus.plexus.classworlds.launcher.Launcher test -pl . -Dtest=NextNameWithMatcherTest -q jackson/core/JsonParser.java jackson/core/it/ModuleInfoIT.java jackson/core/it/iptables jackson/core/uni-w jackson/core/uni-t jackson/core/unisecurity (dns block)
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --enable-native-access=ALL-UNNAMED -classpath /home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.11/a2d47e15/boot/plexus-classworlds-2.9.0.jar -Dclassworlds.conf=/home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.11/a2d47e15/bin/m2.conf -Dmaven.home=/home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.11/a2d47e15 -Dlibrary.jansi.path=/home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.11/a2d47e15/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/jackson-core/jackson-core org.codehaus.plexus.classworlds.launcher.Launcher test -Dtest=NextNameWithMatcherTest -q (dns block)
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --enable-native-access=ALL-UNNAMED -classpath /usr/share/apache-maven-3.9.13/boot/plexus-classworlds-2.9.0.jar -Dclassworlds.conf=/usr/share/apache-maven-3.9.13/bin/m2.conf -Dmaven.home=/usr/share/apache-maven-3.9.13 -Dlibrary.jansi.path=/usr/share/apache-maven-3.9.13/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/jackson-core/jackson-core org.codehaus.plexus.classworlds.launcher.Launcher test -Dtest=NextNameWithMatcherTest -q --no-transfer-progress -Dmaven.repo.local=/home/REDACTED/.m2/repository (dns block)
• https://api.github.com/repos/FasterXML/jackson-base/branches
  • Triggering command: /usr/bin/curl curl -s REDACTED (http block)
• https://api.github.com/repos/FasterXML/jackson-base/contents/pom.xml
  • Triggering command: /usr/bin/curl curl -s REDACTED (http block)
• https://api.github.com/repos/FasterXML/jackson-parent/branches
  • Triggering command: /usr/bin/curl curl -s REDACTED (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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[cowtowncoder]

No, this is wrong kind of defensive coding. Name matcher must be set and we should not sprinkle null checks all over codebase.