Fix infinite loops in ObservableInputStream read(*) when an exception is

caught but not re-thrown.

Author: Gary Gregory

src/changes/changes.xml

@@ -108,6 +108,9 @@ The <action> type attribute can be add,update,fix,remove.
       <action issue="IO-705" dev="ggregory" type="fix" due-to="Hao Zhong, Gary Gregory">
         LockableFileWriter.close() should fail when the lock file cannot be deleted.
       </action>
+      <action issue="IO-705" dev="ggregory" type="fix" due-to="Hao Zhong, Gary Gregory">
+        Fix infinite loops in ObservableInputStream read(*) when an exception is caught but not re-thrown.
+      </action>
       <!-- ADD -->
       <action dev="ggregory" type="add" due-to="Gary Gregory">
         Add FileSystemProviders class.

src/main/java/org/apache/commons/io/input/ObservableInputStream.java

@@ -244,6 +244,7 @@ protected void noteFinished() throws IOException {
     private void notify(final byte[] buffer, final int offset, int result, IOException ioe) throws IOException {
         if (ioe != null) {
             noteError(ioe);
+            throw ioe;
         } else if (result == EOF) {
             noteFinished();
         } else if (result > 0) {
@@ -257,11 +258,12 @@ public int read() throws IOException {
         IOException ioe = null;
         try {
             result = super.read();
-        } catch (final IOException pException) {
-            ioe = pException;
+        } catch (final IOException ex) {
+            ioe = ex;
         }
         if (ioe != null) {
             noteError(ioe);
+            throw ioe;
         } else if (result == EOF) {
             noteFinished();
         } else {
@@ -276,8 +278,8 @@ public int read(final byte[] buffer) throws IOException {
         IOException ioe = null;
         try {
             result = super.read(buffer);
-        } catch (final IOException pException) {
-            ioe = pException;
+        } catch (final IOException ex) {
+            ioe = ex;
         }
         notify(buffer, 0, result, ioe);
         return result;
@@ -289,8 +291,8 @@ public int read(final byte[] buffer, final int offset, final int length) throws
         IOException ioe = null;
         try {
             result = super.read(buffer, offset, length);
-        } catch (final IOException pException) {
-            ioe = pException;
+        } catch (final IOException ex) {
+            ioe = ex;
         }
         notify(buffer, offset, result, ioe);
         return result;

src/test/java/org/apache/commons/io/input/ObservableInputStreamTest.java

@@ -19,6 +19,7 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
@@ -125,6 +126,27 @@ public long getFinishedCount() {
 
     }
 
+    @Test
+    public void testBrokenInputStreamRead() throws IOException {
+        try (final ObservableInputStream ois = new ObservableInputStream(new BrokenInputStream())) {
+            assertThrows(IOException.class, () -> ois.read());
+        }
+    }
+
+    @Test
+    public void testBrokenInputStreamReadBuffer() throws IOException {
+        try (final ObservableInputStream ois = new ObservableInputStream(new BrokenInputStream())) {
+            assertThrows(IOException.class, () -> ois.read(new byte[1]));
+        }
+    }
+
+    @Test
+    public void testBrokenInputStreamReadSubBuffer() throws IOException {
+        try (final ObservableInputStream ois = new ObservableInputStream(new BrokenInputStream())) {
+            assertThrows(IOException.class, () -> ois.read(new byte[2], 0, 1));
+        }
+    }
+
     /**
      * Tests that {@link Observer#data(int)} is called.
      */