8264777: Handle readNBytes(0): src/test

openjdk · May 10, 2021 · 4fae020 · 4fae020
1 parent 5272d5e
commit 4fae020
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Showing 2 changed files with 6 additions and 1 deletion.
diff --git a/src/java.base/share/classes/java/io/FileInputStream.java b/src/java.base/share/classes/java/io/FileInputStream.java
@@ -319,6 +319,8 @@ public byte[] readAllBytes() throws IOException {
     public byte[] readNBytes(int len) throws IOException {
         if (len < 0)
             throw new IllegalArgumentException("len < 0");
+        if (len == 0)
+            return new byte[0];
 
         long length = length();
         long position = position();

diff --git a/test/jdk/java/io/FileInputStream/ReadXBytes.java b/test/jdk/java/io/FileInputStream/ReadXBytes.java
@@ -86,7 +86,10 @@ public static void main(String args[]) throws IOException {
             int pos = RND.nextInt(size);
             int len = RND.nextInt(size - pos);
             fis.getChannel().position(pos);
-            byte[] nbytes = fis.readNBytes(len);
+            byte[] nbytes = fis.readNBytes(0);
+            if (nbytes.length != 0)
+                throw new RuntimeException("readNBytes() zero length");
+            nbytes = fis.readNBytes(len);
             if (nbytes.length != len)
                 throw new RuntimeException("readNBytes() length");
             if (!Arrays.equals(nbytes, 0, len, bytes, pos, pos + len))