On 09/02/2018 18:01, Alan Bateman wrote:
:
I'll study the patch you have but I think we also need to create
issues to get us to the point where changing this system property in a
running VM doesn't impact running code.
Looking at it again, I think we should change java.io.UnixFileSystem
(and the Windows equivalent) to cache the value of user.dir to avoid
difficult to diagnose issues with bad code changing the value of this
property in a running VM. This should reduce the issue down to cases
where user.dir is changed on the command line (never supported either of
course) to a value that is not "/" but has trailing or duplicate slashes.
When reduced down then the alternatives are to change the native
canonicalize method as you have done or alternatively do it once at
UnixFileSystem initialization time so that canonicalize does not have to
deal with this case. The former would require changing the description
of the function (it currently reads "The input path is assumed to
contain no duplicate slashes"), the latter avoids any changes to the
native implementation.
-Alan
diff -r 0937e5f799df src/java.base/unix/classes/java/io/UnixFileSystem.java
--- a/src/java.base/unix/classes/java/io/UnixFileSystem.java Sat Feb
10 07:06:16 2018 -0500
+++ b/src/java.base/unix/classes/java/io/UnixFileSystem.java Mon Feb
12 10:49:40 2018 +0000
@@ -34,12 +34,14 @@
private final char slash;
private final char colon;
private final String javaHome;
+ private final String userDir;
public UnixFileSystem() {
Properties props = GetPropertyAction.privilegedGetProperties();
slash = props.getProperty("file.separator").charAt(0);
colon = props.getProperty("path.separator").charAt(0);
javaHome = props.getProperty("java.home");
+ userDir = props.getProperty("user.dir");
}
@@ -128,7 +130,11 @@
public String resolve(File f) {
if (isAbsolute(f)) return f.getPath();
- return resolve(System.getProperty("user.dir"), f.getPath());
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ sm.checkPropertyAccess("user.dir");
+ }
+ return resolve(userDir, f.getPath());
}
// Caches for canonicalization results to improve startup performance.
