changeset 32139:caacc3d1a348

8132539: (fs) Files.lines(path).collect() returns wrong value in JDK 9 with certain files Summary: Do not use the Spliterator approach for lines() if the FileChannel size is thought to be zero. Reviewed-by: chegar
author bpb
date Wed, 12 Aug 2015 07:55:24 -0700
parents 23830562d3d1
children 28ab875c1537 932b5c08592e
files jdk/src/java.base/share/classes/java/nio/file/Files.java jdk/test/java/nio/file/Files/StreamTest.java
diffstat 2 files changed, 19 insertions(+), 3 deletions(-) [+]
line wrap: on
line diff
--- a/jdk/src/java.base/share/classes/java/nio/file/Files.java	Wed Aug 12 14:38:09 2015 +0100
+++ b/jdk/src/java.base/share/classes/java/nio/file/Files.java	Wed Aug 12 07:55:24 2015 -0700
@@ -3835,7 +3835,9 @@
             // Obtaining the size from the FileChannel is much faster
             // than obtaining using path.toFile().length()
             long length = fc.size();
-            if (length <= Integer.MAX_VALUE) {
+            // FileChannel.size() may in certain circumstances return zero
+            // for a non-zero length file so disallow this case.
+            if (length > 0 && length <= Integer.MAX_VALUE) {
                 Spliterator<String> s = new FileChannelLinesSpliterator(fc, cs, 0, (int) length);
                 return StreamSupport.stream(s, false)
                         .onClose(Files.asUncheckedRunnable(fc));
--- a/jdk/test/java/nio/file/Files/StreamTest.java	Wed Aug 12 14:38:09 2015 +0100
+++ b/jdk/test/java/nio/file/Files/StreamTest.java	Wed Aug 12 07:55:24 2015 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -22,7 +22,7 @@
  */
 
 /* @test
- * @bug 8006884 8019526
+ * @bug 8006884 8019526 8132539
  * @library ..
  * @build PassThroughFileSystem FaultyFileSystem
  * @run testng StreamTest
@@ -685,4 +685,18 @@
             // expected
         }
     }
+
+    public void testProcFile() throws IOException {
+        if (System.getProperty("os.name").equals("Linux")) {
+            Path path = Paths.get("/proc/cpuinfo");
+            if (Files.exists(path)) {
+                String NEW_LINE = System.getProperty("line.separator");
+                String s =
+                    Files.lines(path).collect(Collectors.joining(NEW_LINE));
+                if (s.length() == 0) {
+                    fail("Files.lines(\"" + path + "\") returns no data");
+                }
+            }
+        }
+    }
 }