Avoid exception when getting zero-length xattrs

Closes: java-native-access#1041
matthiasblaesing · Dec 8, 2018 · fa5bc34 · fa5bc34
1 parent f67b15e
commit fa5bc34
Show file tree

Hide file tree

Showing 3 changed files with 16 additions and 0 deletions.
diff --git a/CHANGES.md b/CHANGES.md
@@ -14,6 +14,7 @@ Bug Fixes
 ---------
 * [#1036](https://github.com/java-native-access/jna/issues/1036): `Advapi32Util.registryValueExists` called on non existing key raises exception instead of returning `false` - [@matthiasblaesing](https://github.com/matthiasblaesing).
 * [#384](https://github.com/java-native-access/jna/issues/384): Android only supports loading libraries through the JVM `System#loadLibrary` mechanism, defaulting `jna.nosys` to `true` disabled that code path - [@matthiasblaesing](https://github.com/matthiasblaesing).
+* [#1041](https://github.com/java-native-access/jna/pull/1041): Avoid IllegalArgumentException when reading xattrs with zero length - [@jrobhoward](https://github.com/jrobhoward).
 
 Release 5.1.0
 =============

diff --git a/contrib/platform/src/com/sun/jna/platform/linux/XAttrUtil.java b/contrib/platform/src/com/sun/jna/platform/linux/XAttrUtil.java
@@ -255,6 +255,10 @@ public static Memory getXAttrAsMemory(String path, String name) throws IOExcepti
                 throw new IOException("errno: " + eno);
             }
 
+            if (retval.longValue() == 0) {
+                return null;
+            }
+
             valueMem = new Memory(retval.longValue());
             retval = XAttr.INSTANCE.getxattr(path, name, valueMem, new size_t(valueMem.size()));
             if (retval.longValue() < 0) {
@@ -352,6 +356,10 @@ public static Memory lGetXAttrAsMemory(String path, String name) throws IOExcept
                 throw new IOException("errno: " + eno);
             }
 
+            if (retval.longValue() == 0) {
+                return null;
+            }
+
             valueMem = new Memory(retval.longValue());
             retval = XAttr.INSTANCE.lgetxattr(path, name, valueMem, new size_t(valueMem.size()));
             if (retval.longValue() < 0) {
@@ -445,6 +453,10 @@ public static Memory fGetXAttrAsMemory(int fd, String name) throws IOException {
                 throw new IOException("errno: " + eno);
             }
 
+            if (retval.longValue() == 0) {
+                return null;
+            }
+
             valueMem = new Memory(retval.longValue());
             retval = XAttr.INSTANCE.fgetxattr(fd, name, valueMem, new size_t(valueMem.size()));
             if (retval.longValue() < 0) {

diff --git a/contrib/platform/src/com/sun/jna/platform/mac/XAttrUtil.java b/contrib/platform/src/com/sun/jna/platform/mac/XAttrUtil.java
@@ -58,6 +58,9 @@ public static String getXAttr(String path, String name) {
 		if (bufferLength < 0)
 			return null;
 
+		if (bufferLength == 0)
+			return "";
+
 		Memory valueBuffer = new Memory(bufferLength);
 		long valueLength = XAttr.INSTANCE.getxattr(path, name, valueBuffer, bufferLength, 0, 0);