fix: NonBlockingInputStream keeps thread alive after EOF (fixes #1879) (#1903)

NonBlockingInputStreamImpl was exiting its reading thread permanently
when the underlying stream returned -1. On terminal fds, a -1 from
FileInputStream.read() (native read() returning 0 bytes) is not
permanent EOF and can occur when VMIN=0. The thread now stays alive
and can service subsequent reads, matching NonBlockingReaderImpl
behavior.

Author: gnodet

terminal/src/main/java/org/jline/utils/NonBlockingInputStreamImpl.java

@@ -217,11 +217,6 @@ private void run() {
                     threadIsReading = false;
                     notify();
                 }
-
-                // If end of stream, exit the loop thread
-                if (byteRead < 0) {
-                    return;
-                }
             }
         } catch (Throwable t) {
             Log.warn("Error in NonBlockingInputStream thread", t);

terminal/src/test/java/org/jline/utils/NonBlockingTest.java

@@ -326,4 +326,27 @@ void testPumpBulkReadLargePayload() throws IOException {
         assertArrayEquals(payload, result);
         assertTrue(sawBulk, "At least one bulk read (n > 1) should have occurred");
     }
+
+    @Test
+    void testNonBlockingInputStreamRecoverAfterEof() throws IOException {
+        java.io.InputStream in = new java.io.InputStream() {
+            private int callCount = 0;
+
+            @Override
+            public int read() {
+                int n = callCount++;
+                if (n == 0) {
+                    return -1;
+                }
+                return 'A';
+            }
+        };
+        NonBlockingInputStreamImpl nbis = new NonBlockingInputStreamImpl("test", in);
+        try {
+            assertEquals(-1, nbis.read(200));
+            assertEquals('A', nbis.read(200));
+        } finally {
+            nbis.close();
+        }
+    }
 }