Cannot invoke "java.lang.CharSequence.length()" because "this.text" is null

### Jenkins and plugins versions report

Environment

```
Jenkins: 2.555.1
OS: Linux - 6.8.0-53-generic
Java: 21.0.10 - Eclipse Adoptium (OpenJDK 64-Bit Server VM)
---
ant:520.vd082ecfb_16a_9
antisamy-markup-formatter:173.v680e3a_b_69ff3
apache-httpcomponents-client-4-api:4.5.14-269.vfa_2321039a_83
asm-api:9.10-211.v7d13903b_a_d89
blueocean-commons:1.27.25
blueocean-core-js:1.27.25
blueocean-dashboard:1.27.25
blueocean-i18n:1.27.25
blueocean-personalization:1.27.25
blueocean-rest:1.27.25
blueocean-web:1.27.25
bootstrap5-api:5.3.8-1038.vee76a_fe825ff
bouncycastle-api:2.30.1.84-291.v9f17b_21896e2
branch-api:2.1280.v0d4e5b_b_460ef
build-timeout:1.40
caffeine-api:3.2.3-194.v31a_b_f7a_b_5a_81
checks-api:402.vca_263b_f200e3
cloudbees-folder:6.1100.ve9eed61d16c4
commons-lang3-api:3.20.0-109.ve43756e2d2b_4
commons-text-api:1.15.0-218.va_61573470393
credentials:1502.v5c95e620ddfe
credentials-binding:720.v3f6decef43ea_
dark-theme:652.vea_da_dfea_e769
data-tables-api:2.3.8-1570.v1cb_1cd2a_0fb_c
display-url-api:2.217.va_6b_de84cc74b_
durable-task:671.v340ff7959010
echarts-api:6.0.0-1287.vfd24c22a_3d00
eddsa-api:0.3.0.1-29.v67e9a_1c969b_b_
email-ext:1933.v45cec755423f
font-awesome-api:7.2.0-990.vf220b_2a_496f9
gerrit-trigger:3.1971.v217d381e3a_5a_
git:5.10.1
git-client:6.6.0
gradle:2.19.1244.v1f9866817fec
gson-api:2.14.0-201.v8eefe5515533
htmlpublisher:427.1
instance-identity:203.v15e81a_1b_7a_38
ionicons-api:94.vcc3065403257
jackson-annotations2-api:2.21-7.v4777a_f3a_a_d47
jackson2-api:2.21.2-436.v29efdb_7418ff
jackson3-api:3.1.3-76.vd9b_7cd2e80b_8
jakarta-activation-api:2.1.4-1
jakarta-mail-api:2.1.5-1
jakarta-xml-bind-api:4.0.6-12.vb_1833c1231d3
javax-activation-api:1.2.0-8
jaxb:2.3.9-143.v5979df3304e6
jenkins-design-language:1.27.25
jjwt-api:0.13.0-141.vd58b_a_9592b_6c
job-import-plugin:143.v044a_2e819b_27
joda-time-api:2.14.2-193.v422b_efce56e0
jquery3-api:3.7.1-687.v68d468e40b_30
jsch:0.2.16-95.v3eecb_55fa_b_78
json-api:20251224-185.v0cc18490c62c
json-path-api:3.0.0-218.vcd4dd1355de2
jsoup:1.22.2-95.vc5d00f1eb_42d
junit:1403.vd9d1413fd205
ldap:807.v7d7de30930cf
localization-support:1.41.v186a_c1569458
localization-zh-cn:371.v23851f835d6b_
lockable-resources:1515.v380548282a_59
lucene-search:438.v6c127ca_fd62e
mailer:534.v1b_36f5864073
matrix-auth:3.2.10
matrix-project:870.v9db_fcfc2f45b_
metrics:4.2.37-494.v06f9a_939d33a_
mina-sshd-api-common:2.17.1-187.v0341274c2905
mina-sshd-api-core:2.17.1-187.v0341274c2905
okhttp-api:5.3.2-200.vedb_720a_cf1f8
parameterized-trigger:893.va_383a_9b_a_4c11
pipeline-build-step:584.vdb_a_2cc3a_d07a_
pipeline-graph-analysis:254.v0f63a_a_447dca_
pipeline-graph-view:903.v86ded4d9c36b_
pipeline-groovy-lib:797.v90ea_a_9b_e45a_0
pipeline-input-step:551.vdff487c5998c
pipeline-milestone-step:152.v6e22b_8cfc66c
pipeline-model-api:2.2277.v00573e73ddf1
pipeline-model-definition:2.2277.v00573e73ddf1
pipeline-model-extensions:2.2277.v00573e73ddf1
pipeline-rest-api:2.41
pipeline-stage-step:345.va_96187909426
pipeline-stage-tags-metadata:2.2277.v00573e73ddf1
pipeline-stage-view:2.41
plain-credentials:199.v9f8e1f741799
plugin-util-api:7.1341.v039f146993d9
prism-api:1.30.0-727.vc475481f034d
pubsub-light:1.19
resource-disposer:0.25
role-strategy:848.va_a_ea_673cf0b_c
scm-api:728.vc30dcf7a_0df5
script-security:1402.v94c9ce464861
snakeyaml-api:2.5-149.v72471e9c6371
snakeyaml-engine-api:3.0.1-5.vd98ea_ff3b_92e
sse-gateway:1.29
ssh-credentials:372.va_250881b_08cd
ssh-slaves:3.1097.v868116049892
structs:362.va_b_695ef4fdf9
theme-manager:346.v06cca_64c6a_37
timestamper:1.30
token-macro:477.vd4f0dc3cb_cf1
trilead-api:2.284.v1974ea_324382
variant:70.va_d9f17f859e0
woodstox-core-api:7.1.1-1.v4d297985f397
workflow-aggregator:608.v67378e9d3db_1
workflow-api:1413.v2ff1a_5e720fa_
workflow-basic-steps:1098.v808b_fd7f8cf4
workflow-cps:4331.v9d06ed4658ff
workflow-durable-task-step:1479.v56e587f413a_7
workflow-job:1571.1580.v18e46842c125
workflow-multibranch:821.vc3b_4ea_780798
workflow-scm-step:466.va_d69e602552b_
workflow-step-api:724.v538c2362b_dfb_
workflow-support:1015.v785e5a_b_b_8b_22
ws-cleanup:0.49
```

### What Operating System are you using (both controller, and any agents involved in the problem)?

jenkins runtime os:Debian GNU/Linux 13 \n \l(by call the container jenkins/jenkins:2.555.1-lts-jdk21)

### Reproduction steps

gerrit trigger config page:

### Expected Results

can trigger success

### Actual Results

1. trigger success but jenkins thrown many error log like below:
Exception thrown during event handling.
java.lang.NullPointerException: Cannot invoke "java.lang.CharSequence.length()" because "this.text" is null
at java.base/java.util.regex.Matcher.getTextLength(Unknown Source)
at java.base/java.util.regex.Matcher.reset(Unknown Source)
at java.base/java.util.regex.Matcher.(Unknown Source)
at java.base/java.util.regex.Pattern.matcher(Unknown Source)
at PluginClassLoader for gerrit-trigger//com.sonyericsson.hudson.plugins.gerrit.trigger.hudsontrigger.events.PluginCommentAddedContainsEvent.match(PluginCommentAddedContainsEvent.java:117)
at PluginClassLoader for gerrit-trigger//com.sonyericsson.hudson.plugins.gerrit.trigger.hudsontrigger.GerritTrigger.commentAddedMatch(GerritTrigger.java:1250)
at PluginClassLoader for gerrit-trigger//com.sonyericsson.hudson.plugins.gerrit.trigger.hudsontrigger.EventListener.gerritEvent(EventListener.java:213)
Caused: java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at PluginClassLoader for gerrit-trigger//com.sonymobile.tools.gerrit.gerritevents.GerritHandler.notifyListener(GerritHandler.java:579)
at PluginClassLoader for gerrit-trigger//com.sonymobile.tools.gerrit.gerritevents.GerritHandler.notifyListeners(GerritHandler.java:559)
at PluginClassLoader for gerrit-trigger//com.sonyericsson.hudson.plugins.gerrit.trigger.JenkinsAwareGerritHandler.notifyListeners(JenkinsAwareGerritHandler.java:80)
at PluginClassLoader for gerrit-trigger//com.sonymobile.tools.gerrit.gerritevents.workers.AbstractGerritEventWork.perform(AbstractGerritEventWork.java:46)
at PluginClassLoader for gerrit-trigger//com.sonymobile.tools.gerrit.gerritevents.workers.AbstractJsonObjectWork.perform(AbstractJsonObjectWork.java:77)
at PluginClassLoader for gerrit-trigger//com.sonymobile.tools.gerrit.gerritevents.workers.StreamEventsStringWork.perform(StreamEventsStringWork.java:74)
at PluginClassLoader for gerrit-trigger//com.sonymobile.tools.gerrit.gerritevents.GerritHandler$EventWorker.workEvent(GerritHandler.java:337)
at PluginClassLoader for gerrit-trigger//com.sonymobile.tools.gerrit.gerritevents.GerritHandler$EventWorker.run(GerritHandler.java:319)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.base/java.lang.Thread.run(Unknown Source)

### Anything else?

_No response_

### Are you interested in contributing a fix?

_No response_

Start at PluginCommentAddedContainsEvent.java:117, then trace how GerritTrigger.commentAddedMatch and EventListener.gerritEvent supply the comment text. Reproduce the Gerrit trigger event and inspect the null input path; done means the trigger succeeds without the reported NullPointerException or repeated error logs.

Written by the indexing model from the issue text.