Make unwrapCorrupt Check Suppressed Ex.

* As discussed in elastic#24800 we want to check for suppressed corruption
indicating exceptions here as well to more reliably categorize
corruption related exceptions
* Closes elastic#24800, 41201

Author: original-brownbear

server/src/main/java/org/elasticsearch/ExceptionsHelper.java

@@ -176,9 +176,17 @@ public static <T extends Throwable> T useOrSuppress(T first, T second) {
     }
 
     public static IOException unwrapCorruption(Throwable t) {
-        return (IOException) unwrap(t, CorruptIndexException.class,
-                                       IndexFormatTooOldException.class,
-                                       IndexFormatTooNewException.class);
+        IOException corruptionException =
+            (IOException) unwrap(t, CorruptIndexException.class, IndexFormatTooOldException.class, IndexFormatTooNewException.class);
+        if (corruptionException == null && t != null) {
+            for (Throwable suppressed : t.getSuppressed()) {
+                corruptionException = unwrapCorruption(suppressed);
+                if (corruptionException != null) {
+                    return corruptionException;
+                }
+            }
+        }
+        return corruptionException;
     }
 
     public static Throwable unwrap(Throwable t, Class<?>... clazzes) {

server/src/test/java/org/elasticsearch/indices/recovery/RecoverySourceHandlerTests.java

@@ -438,10 +438,12 @@ protected void failEngine(IOException cause) {
             handler.sendFiles(store, metas.toArray(new StoreFileMetaData[0]), () -> 0);
             fail("exception index");
         } catch (RuntimeException ex) {
-            assertNull(ExceptionsHelper.unwrapCorruption(ex));
+            final IOException unwrappedCorruption = ExceptionsHelper.unwrapCorruption(ex);
             if (throwCorruptedIndexException) {
+                assertNotNull(unwrappedCorruption);
                 assertEquals(ex.getMessage(), "[File corruption occurred on recovery but checksums are ok]");
             } else {
+                assertNull(unwrappedCorruption);
                 assertEquals(ex.getMessage(), "boom");
             }
         } catch (CorruptIndexException ex) {