From 05bfffa247c470d12a5b93326a05d3fd0d890ce0 Mon Sep 17 00:00:00 2001
From: Michael Barker <mikeb01@gmail.com>
Date: Sat, 3 Nov 2018 17:41:10 +0530
Subject: [PATCH 1/2] bz-62849 Check for filesystem loops due to symbolic
 links, in DirectoryScanner and Delete task

---
 src/etc/testcases/core/directoryscanner.xml       |  5 +++++
 .../org/apache/tools/ant/DirectoryScanner.java    | 12 ++++++++++++
 .../org/apache/tools/ant/taskdefs/Delete.java     | 15 ++++++++++++++-
 .../apache/tools/ant/DirectoryScannerTest.java    | 14 ++++++++++++++
 4 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/src/etc/testcases/core/directoryscanner.xml b/src/etc/testcases/core/directoryscanner.xml
index 7e8683a4a..71eb88bf7 100644
--- a/src/etc/testcases/core/directoryscanner.xml
+++ b/src/etc/testcases/core/directoryscanner.xml
@@ -38,4 +38,9 @@
         <touch file="${output}/alpha/beta/gamma/gamma.xml"/>
     </target>
 
+    <target name="symlink-nested-setup" depends="setUp">
+        <symlink link="${output}/alpha/beta/gamma/beta-link" resource="${output}/alpha/beta"/>
+        <touch file="${output}/alpha/beta/gamma/gamma.xml"/>
+    </target>
+
 </project>
diff --git a/src/main/org/apache/tools/ant/DirectoryScanner.java b/src/main/org/apache/tools/ant/DirectoryScanner.java
index a0e7837e4..15caa4025 100644
--- a/src/main/org/apache/tools/ant/DirectoryScanner.java
+++ b/src/main/org/apache/tools/ant/DirectoryScanner.java
@@ -1258,6 +1258,18 @@ public class DirectoryScanner
             final String name = vpath + newFile;
             final TokenizedPath newPath = new TokenizedPath(path, newFile);
             final File file = new File(dir, newFile);
+
+            try {
+                // check if it's a filesystem "loop" due to symbolic links
+                if (FileUtils.getFileUtils().isLeadingPath(file.getAbsoluteFile(),
+                    dir.getAbsoluteFile(), true)) {
+                    continue;
+                }
+            } catch (IOException e) {
+                System.err.println("Failed to determine if " + file + " causes a " +
+                        "filesystem loop due to symbolic link; continuing");
+            }
+
             final String[] children = file.list();
             if (children == null || (children.length == 0 && file.isFile())) {
                 if (isIncluded(newPath)) {
diff --git a/src/main/org/apache/tools/ant/taskdefs/Delete.java b/src/main/org/apache/tools/ant/taskdefs/Delete.java
index f887695b1..fdddbbf2d 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Delete.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Delete.java
@@ -19,6 +19,7 @@
 package org.apache.tools.ant.taskdefs;
 
 import java.io.File;
+import java.io.IOException;
 import java.util.Arrays;
 import java.util.Comparator;
 import java.util.Iterator;
@@ -771,7 +772,19 @@ public class Delete extends MatchingTask {
         }
         for (String s : list) {
             File f = new File(d, s);
-            if (f.isDirectory()) {
+
+            boolean isFsLoop = false;
+
+            try {
+                isFsLoop = SYMLINK_UTILS.isSymbolicLink(f) &&
+                    FileUtils.getFileUtils().isLeadingPath(f.getAbsoluteFile(),
+                        d.getAbsoluteFile(), true);
+            } catch (IOException e) {
+                log("Failed to check if " + f + " causes a filesystem loop due to " +
+                        "symbolic link; continuing");
+            }
+
+            if (f.isDirectory() && !isFsLoop) {
                 removeDir(f);
             } else {
                 log("Deleting " + f.getAbsolutePath(), quiet ? Project.MSG_VERBOSE : verbosity);
diff --git a/src/tests/junit/org/apache/tools/ant/DirectoryScannerTest.java b/src/tests/junit/org/apache/tools/ant/DirectoryScannerTest.java
index 819d4e50e..2abd94f31 100644
--- a/src/tests/junit/org/apache/tools/ant/DirectoryScannerTest.java
+++ b/src/tests/junit/org/apache/tools/ant/DirectoryScannerTest.java
@@ -132,6 +132,20 @@ public class DirectoryScannerTest {
                 new String[] {"alpha/beta/gamma"});
     }
 
+    @Test
+    public void testAllowRecursiveSymlinks() {
+
+        assumeTrue("Current system does not support Symlinks", supportsSymlinks);
+
+        buildRule.getProject().executeTarget("symlink-nested-setup");
+        DirectoryScanner ds = new DirectoryScanner();
+        ds.setBasedir(new File(buildRule.getProject().getProperty("output")));
+        ds.setIncludes(new String[] {"alpha/beta/gamma/"});
+        ds.scan();
+        compareFiles(ds, new String[] {"alpha/beta/gamma/gamma.xml"},
+            new String[] {"alpha/beta/gamma"});
+    }
+
     @Test
     public void testProhibitSymlinks() {
         assumeTrue("Current system does not support Symlinks", supportsSymlinks);

From 506c3ab47a1d69ecff691cc535ae8368d0aeb1db Mon Sep 17 00:00:00 2001
From: Jaikiran Pai <jaikiran@apache.org>
Date: Sat, 3 Nov 2018 17:48:47 +0530
Subject: [PATCH 2/2] Record the fix for bz-62849, contributed by Michael
 Barker

---
 CONTRIBUTORS     | 1 +
 WHATSNEW         | 5 +++++
 contributors.xml | 4 ++++
 3 files changed, 10 insertions(+)

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 7005c7562..7d4a3fd69 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -263,6 +263,7 @@ Matthew Kuperus Heun
 Matthew Watson
 Matthew Yanos
 Matthias Bhend
+Michael Barker
 Michael Bayne
 Michael Clarke
 Michael Davey
diff --git a/WHATSNEW b/WHATSNEW
index e5bfed371..ab6d0cdad 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -16,6 +16,11 @@ Fixed bugs:
    an incorrect compression level for a zip entry. This is now fixed.
    Bugzilla Report 62686
 
+ * A filesystem "loop" caused due to symbolic links could trigger an
+   out of memory error in the org.apache.tools.ant.DirectoryScanner
+   This has now been fixed.
+   Bugzilla Report 62849
+
 Other changes:
 --------------
  * generatekey task now supports SubjectAlternativeName during key
diff --git a/contributors.xml b/contributors.xml
index a62b1d477..88b7a8c1e 100644
--- a/contributors.xml
+++ b/contributors.xml
@@ -1073,6 +1073,10 @@
     <first>Matthew</first>
     <last>Yanos</last>
   </name>
+  <name>
+    <first>Michael</first>
+    <last>Barker</last>
+  </name>
   <name>
     <first>Michael</first>
     <last>Bayne</last>