(commons-text) branch master updated: Guard empty split result in DnsStringLookup.lookup (#765)

[ggregory]

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garydgregory pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/commons-text.git


The following commit(s) were added to refs/heads/master by this push:
     new f04ebec0 Guard empty split result in DnsStringLookup.lookup (#765)
f04ebec0 is described below

commit f04ebec055370aba39ce747a2a2b60697d8d1ac6
Author: Javid Khan <dxbja...@gmail.com>
AuthorDate: Wed Aug 26 02:05:02 2026 +0530

    Guard empty split result in DnsStringLookup.lookup (#765)
---
 src/main/java/org/apache/commons/text/lookup/DnsStringLookup.java | 3 +++
 .../java/org/apache/commons/text/lookup/DnsStringLookupTest.java  | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/src/main/java/org/apache/commons/text/lookup/DnsStringLookup.java 
b/src/main/java/org/apache/commons/text/lookup/DnsStringLookup.java
index 028879c2..bbc38984 100644
--- a/src/main/java/org/apache/commons/text/lookup/DnsStringLookup.java
+++ b/src/main/java/org/apache/commons/text/lookup/DnsStringLookup.java
@@ -87,6 +87,9 @@ final class DnsStringLookup extends AbstractStringLookup {
         }
         final String[] keys = key.trim().split("\\|");
         final int keyLen = keys.length;
+        if (keyLen == 0) {
+            return null;
+        }
         final String subKey = keys[0].trim();
         final String subValue = keyLen < 2 ? key : keys[1].trim();
         try {
diff --git 
a/src/test/java/org/apache/commons/text/lookup/DnsStringLookupTest.java 
b/src/test/java/org/apache/commons/text/lookup/DnsStringLookupTest.java
index b62dee6a..a5c5f252 100644
--- a/src/test/java/org/apache/commons/text/lookup/DnsStringLookupTest.java
+++ b/src/test/java/org/apache/commons/text/lookup/DnsStringLookupTest.java
@@ -73,6 +73,14 @@ class DnsStringLookupTest {
         assertTrue(matched);
     }
 
+    @Test
+    void testDelimiterOnlyKey() {
+        // A key that is only delimiter/whitespace splits to an empty array; 
must not throw.
+        assertNull(DnsStringLookup.INSTANCE.apply("|"));
+        assertNull(DnsStringLookup.INSTANCE.apply("||"));
+        assertNull(DnsStringLookup.INSTANCE.apply("  |  "));
+    }
+
     @Test
     void testNull() {
         assertNull(DnsStringLookup.INSTANCE.apply(null));