diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 4c9fdc9ab..f1f480c98 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -230,6 +230,7 @@ Steve Morin
 Steven E. Newton
 Takashi Okamoto
 Tariq Master
+Trejkaz Xaoza
 Thomas Butz
 Thomas Christen
 Thomas Christensen
diff --git a/WHATSNEW b/WHATSNEW
index 45039138a..4426f7790 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -18,6 +18,7 @@ Fixed bugs:
 * Exception reporting in <copy> was broken. Bugzilla report 40300.
 * Handling of corrupt tar files, TarInputStream.read() never returns EOF.
   Bugzilla report 39924.
+* Some bugs in ReaderInputStream. Bugzilla report 39635.
 
 Other changes:
 --------------
diff --git a/contributors.xml b/contributors.xml
index 6aa1f4288..e7b3cf20d 100644
--- a/contributors.xml
+++ b/contributors.xml
@@ -958,6 +958,10 @@
     <first>Tom</first>
     <last>Eugelink</last>
   </name>
+  <name>
+    <first>Trejkaz</first>
+    <last>Xaoz</last>
+  </name>
   <name>
     <first>Ulrich</first>
     <last>Schmidt</last>
diff --git a/src/main/org/apache/tools/ant/util/ReaderInputStream.java b/src/main/org/apache/tools/ant/util/ReaderInputStream.java
index 3a9065673..95c2071f0 100755
--- a/src/main/org/apache/tools/ant/util/ReaderInputStream.java
+++ b/src/main/org/apache/tools/ant/util/ReaderInputStream.java
@@ -85,16 +85,13 @@ public class ReaderInputStream extends InputStream {
         } else {
             byte[] buf = new byte[1];
             if (read(buf, 0, 1) <= 0) {
-                result = -1;
+                return -1;
+            } else {
+                result = buf[0];
             }
-            result = buf[0];
-        }
-
-        if (result < -1) {
-            result += 256;
         }
 
-        return result;
+        return result & 0xFF;
     }
 
     /**
@@ -112,7 +109,9 @@ public class ReaderInputStream extends InputStream {
         if (in == null) {
             throw new IOException("Stream Closed");
         }
-
+        if (len == 0) {
+            return 0;
+        }
         while (slack == null) {
             char[] buf = new char[len]; // might read too much
             int n = in.read(buf);