diff --git a/WHATSNEW b/WHATSNEW
index 09aabe7b8..ecc54180c 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -670,6 +670,10 @@ Other changes:
    processor.
    Bugzilla Issue 46612.
 
+ * the ZIP library will now ignore ZIP extra fields that don't specify
+   a size.
+   Bugzilla Report 42940.
+
 Changes from Ant 1.7.0 TO Ant 1.7.1
 =============================================
 
diff --git a/src/main/org/apache/tools/zip/ExtraFieldUtils.java b/src/main/org/apache/tools/zip/ExtraFieldUtils.java
index 0aa5cbd11..befd42322 100644
--- a/src/main/org/apache/tools/zip/ExtraFieldUtils.java
+++ b/src/main/org/apache/tools/zip/ExtraFieldUtils.java
@@ -117,10 +117,6 @@ public class ExtraFieldUtils {
             }
             start += (length + WORD);
         }
-        if (start != data.length) { // array not exhausted
-            throw new ZipException("data starting at " + start
-                + " is in unknown format");
-        }
 
         ZipExtraField[] result = new ZipExtraField[v.size()];
         return (ZipExtraField[]) v.toArray(result);
diff --git a/src/main/org/apache/tools/zip/ZipEntry.java b/src/main/org/apache/tools/zip/ZipEntry.java
index 3223454b9..d1e1deb2c 100644
--- a/src/main/org/apache/tools/zip/ZipEntry.java
+++ b/src/main/org/apache/tools/zip/ZipEntry.java
@@ -252,7 +252,7 @@ public class ZipEntry extends java.util.zip.ZipEntry implements Cloneable {
         try {
             setExtraFields(ExtraFieldUtils.parse(extra));
         } catch (Exception e) {
-            throw new RuntimeException(e.getMessage());
+            throw new RuntimeException(e.getMessage(), e);
         }
     }
 
diff --git a/src/main/org/apache/tools/zip/ZipExtraField.java b/src/main/org/apache/tools/zip/ZipExtraField.java
index 622ff1738..649fca005 100644
--- a/src/main/org/apache/tools/zip/ZipExtraField.java
+++ b/src/main/org/apache/tools/zip/ZipExtraField.java
@@ -64,7 +64,7 @@ public interface ZipExtraField {
     byte[] getLocalFileDataData();
 
     /**
-     * The actual data to put central directory - without Header-ID or
+     * The actual data to put into central directory - without Header-ID or
      * length specifier.
      * @return the data
      * @since 1.1
diff --git a/src/tests/antunit/taskdefs/unzip-test.xml b/src/tests/antunit/taskdefs/unzip-test.xml
index ed75de469..45a878f54 100644
--- a/src/tests/antunit/taskdefs/unzip-test.xml
+++ b/src/tests/antunit/taskdefs/unzip-test.xml
@@ -44,6 +44,16 @@
     <au:assertFileExists file="${output}/foo/file"/>
   </target>
 
+  <target name="testTwoByteExtraFieldInLFH"
+          description="https://issues.apache.org/bugzilla/show_bug.cgi?id=42940"
+          >
+    <mkdir dir="${input}"/>
+    <mkdir dir="${output}"/>
+    <copy file="zip/Bugzilla-42940.zip" tofile="${input}/test.zip"/>
+    <unzip src="${input}/test.zip" dest="${output}"/>
+    <au:assertFileExists file="${output}/META-INF/MANIFEST.MF"/>
+  </target>
+
   <target name="testArchiveIsClosedForInvalidZips"
           description="https://issues.apache.org/bugzilla/show_bug.cgi?id=46559"
           >
diff --git a/src/tests/antunit/taskdefs/zip/Bugzilla-46559.zip b/src/tests/antunit/taskdefs/zip/Bugzilla-46559.zip
index 2f7566082..711402b6d 100644
Binary files a/src/tests/antunit/taskdefs/zip/Bugzilla-46559.zip and b/src/tests/antunit/taskdefs/zip/Bugzilla-46559.zip differ
diff --git a/src/tests/junit/org/apache/tools/zip/ExtraFieldUtilsTest.java b/src/tests/junit/org/apache/tools/zip/ExtraFieldUtilsTest.java
index c405138f7..13e07193e 100644
--- a/src/tests/junit/org/apache/tools/zip/ExtraFieldUtilsTest.java
+++ b/src/tests/junit/org/apache/tools/zip/ExtraFieldUtilsTest.java
@@ -40,7 +40,7 @@ public class ExtraFieldUtilsTest extends TestCase implements UnixStat {
         a.setDirectory(true);
         dummy = new UnrecognizedExtraField();
         dummy.setHeaderId(new ZipShort(1));
-        dummy.setLocalFileDataData(new byte[0]);
+        dummy.setLocalFileDataData(new byte[] {0});
         dummy.setCentralDirectoryData(new byte[] {0});
 
         aLocal = a.getLocalFileDataData();
@@ -68,7 +68,7 @@ public class ExtraFieldUtilsTest extends TestCase implements UnixStat {
         assertEquals("mode field 1", 040755,
                      ((AsiExtraField) ze[0]).getMode());
         assertTrue("type field 2", ze[1] instanceof UnrecognizedExtraField);
-        assertEquals("data length field 2", 0,
+        assertEquals("data length field 2", 1,
                      ze[1].getLocalFileDataLength().getValue());
 
         byte[] data2 = new byte[data.length-1];