fix exception overwriting

cds-feature-attachments/src/main/java/com/sap/cds/feature/attachments/handler/applicationservice/readhelper/LazyProxyInputStream.java

@@ -58,11 +58,20 @@ public void close() throws IOException {
   }
 
   private InputStream getDelegate() {
-    attachmentStatusValidator.verifyStatus(status);
-
     if (delegate == null) {
       logger.debug("Creating delegate input stream");
-      delegate = inputStreamSupplier.get();
+      try {
+        delegate = inputStreamSupplier.get();
+        attachmentStatusValidator.verifyStatus(status);
+      } catch (RuntimeException originalException) {
+        try {
+          attachmentStatusValidator.verifyStatus(status);
+          throw originalException;
+        } catch (AttachmentStatusException statusException) {
+          originalException.addSuppressed(statusException);
+          throw originalException;
+        }
+      }
     }
     return delegate;
   }

cds-feature-attachments/src/test/java/com/sap/cds/feature/attachments/handler/applicationservice/readhelper/LazyProxyInputStreamTest.java

@@ -16,6 +16,7 @@
 
 import com.sap.cds.feature.attachments.generated.cds4j.sap.attachments.StatusCode;
 import com.sap.cds.feature.attachments.service.AttachmentService;
+import com.sap.cds.services.ServiceException;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.io.IOException;
 import java.io.InputStream;
@@ -137,4 +138,76 @@ void noExceptionIfCorrectStatus() {
 
     assertDoesNotThrow(() -> cut.read());
   }
+
+  @Test
+  void originalExceptionPreservedWhenSupplierFails() {
+    // Test the core fix: original exception from supplier should be preserved
+    // even when status validation also fails
+    ServiceException originalException = new ServiceException("Failed to retrieve document content for file with ID: test123");
+    AttachmentStatusException statusException = AttachmentStatusException.getNotCleanException();
+
+    // Mock supplier to throw original exception
+    when(attachmentService.readAttachment(any())).thenThrow(originalException);
+    // Mock status validator to also throw exception
+    doThrow(statusException).when(attachmentStatusValidator).verifyStatus(StatusCode.INFECTED);
+
+    cut = new LazyProxyInputStream(
+        () -> attachmentService.readAttachment(any()),
+        attachmentStatusValidator,
+        StatusCode.INFECTED);
+
+    // The original exception should be thrown, not the status exception
+    ServiceException thrownException = assertThrows(ServiceException.class, () -> cut.read());
+
+    // Verify the original exception is preserved
+    assertThat(thrownException).isEqualTo(originalException);
+    assertThat(thrownException.getMessage()).isEqualTo("Failed to retrieve document content for file with ID: test123");
+
+    // Verify the status exception is added as suppressed exception for context
+    assertThat(thrownException.getSuppressed()).hasSize(1);
+    assertThat(thrownException.getSuppressed()[0]).isInstanceOf(AttachmentStatusException.class);
+  }
+
+  @Test
+  void originalExceptionPreservedWhenStatusValidationPasses() {
+    // Test edge case: supplier fails but status validation passes
+    // In this case, we still want the original exception, not status exception
+    ServiceException originalException = new ServiceException("Network connection failed");
+
+    // Mock supplier to throw original exception
+    when(attachmentService.readAttachment(any())).thenThrow(originalException);
+    // Status validator should pass (no exception thrown)
+
+    cut = new LazyProxyInputStream(
+        () -> attachmentService.readAttachment(any()),
+        attachmentStatusValidator,
+        StatusCode.CLEAN);
+
+    // The original exception should be thrown
+    ServiceException thrownException = assertThrows(ServiceException.class, () -> cut.read());
+
+    // Verify the original exception is preserved
+    assertThat(thrownException).isEqualTo(originalException);
+    assertThat(thrownException.getMessage()).isEqualTo("Network connection failed");
+
+    // No suppressed exceptions should be present since status validation passed
+    assertThat(thrownException.getSuppressed()).isEmpty();
+  }
+
+  @Test
+  void statusValidationOnlyWhenSupplierSucceeds() {
+    // Test that status validation happens after successful stream creation
+    // This ensures we don't pre-emptively block access due to status when the underlying issue might be different
+
+    cut = new LazyProxyInputStream(
+        () -> attachmentService.readAttachment(any()),
+        attachmentStatusValidator,
+        StatusCode.CLEAN);
+
+    assertDoesNotThrow(() -> cut.read());
+
+    // Verify status was validated after supplier was called
+    verify(attachmentService).readAttachment(any());
+    verify(attachmentStatusValidator).verifyStatus(StatusCode.CLEAN);
+  }
 }