Correctly detect ContentLengthMismatchException and retry.

The retry doesn't work if the ContentLengthMismatchException is wrapped in an IOException.

PiperOrigin-RevId: 636107102
Change-Id: I721e0be325dfd7c4e8a3dd697f5d513f42bcb7aa

src/main/java/com/google/devtools/build/lib/bazel/repository/downloader/DownloadManager.java

@@ -340,7 +340,7 @@ private Path downloadInExecutor(
       throw new IOException(getRewriterBlockedAllUrlsMessage(originalUrls));
     }
 
-    for (int attempt = 0; attempt <= retries; ++attempt) {
+    for (int attempt = 0; ; ++attempt) {
       try {
         downloader.download(
             rewrittenUrls,
@@ -353,12 +353,12 @@ private Path downloadInExecutor(
             clientEnv,
             type);
         break;
-      } catch (ContentLengthMismatchException e) {
-        if (attempt == retries) {
-          throw e;
-        }
       } catch (InterruptedIOException e) {
         throw new InterruptedException(e.getMessage());
+      } catch (IOException e) {
+        if (!shouldRetryDownload(e, attempt)) {
+          throw e;
+        }
       }
     }
 
@@ -372,6 +372,24 @@ private Path downloadInExecutor(
     return destination;
   }
 
+  private boolean shouldRetryDownload(IOException e, int attempt) {
+    if (attempt >= retries) {
+      return false;
+    }
+
+    if (e instanceof ContentLengthMismatchException) {
+      return true;
+    }
+
+    for (var suppressed : e.getSuppressed()) {
+      if (suppressed instanceof ContentLengthMismatchException) {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
   /**
    * Downloads the contents of one URL and reads it into a byte array.
    *
@@ -447,8 +465,8 @@ public byte[] downloadAndReadOneUrlForBzlmod(
     }
 
     HttpDownloader httpDownloader = new HttpDownloader();
-    byte[] content = null;
-    for (int attempt = 0; attempt <= retries; ++attempt) {
+    byte[] content;
+    for (int attempt = 0; ; ++attempt) {
       try {
         content =
             httpDownloader.downloadAndReadOneUrl(
@@ -458,12 +476,12 @@ public byte[] downloadAndReadOneUrlForBzlmod(
                 eventHandler,
                 clientEnv);
         break;
-      } catch (ContentLengthMismatchException e) {
-        if (attempt == retries) {
-          throw e;
-        }
       } catch (InterruptedIOException e) {
         throw new InterruptedException(e.getMessage());
+      } catch (IOException e) {
+        if (!shouldRetryDownload(e, attempt)) {
+          throw e;
+        }
       }
     }
     if (content == null) {

src/test/java/com/google/devtools/build/lib/bazel/repository/downloader/HttpDownloaderTest.java

@@ -713,4 +713,49 @@ public void download_contentLengthMismatch_retries() throws Exception {
     String content = new String(ByteStreams.toByteArray(result.getInputStream()), UTF_8);
     assertThat(content).isEqualTo("content");
   }
+
+  @Test
+  public void download_contentLengthMismatchWithOtherErrors_retries() throws Exception {
+    Downloader downloader = mock(Downloader.class);
+    int retires = 5;
+    DownloadManager downloadManager = new DownloadManager(repositoryCache, downloader);
+    downloadManager.setRetries(retires);
+    AtomicInteger times = new AtomicInteger(0);
+    byte[] data = "content".getBytes(UTF_8);
+    doAnswer(
+            (Answer<Void>)
+                invocationOnMock -> {
+                  if (times.getAndIncrement() < 3) {
+                    IOException e = new IOException();
+                    e.addSuppressed(new ContentLengthMismatchException(0, data.length));
+                    e.addSuppressed(new IOException());
+                    throw e;
+                  }
+                  Path output = invocationOnMock.getArgument(5, Path.class);
+                  try (OutputStream outputStream = output.getOutputStream()) {
+                    ByteStreams.copy(new ByteArrayInputStream(data), outputStream);
+                  }
+
+                  return null;
+                })
+        .when(downloader)
+        .download(any(), any(), any(), any(), any(), any(), any(), any(), any());
+
+    Path result =
+        downloadManager.download(
+            ImmutableList.of(new URL("http://localhost")),
+            ImmutableMap.of(),
+            ImmutableMap.of(),
+            Optional.empty(),
+            "testCanonicalId",
+            Optional.empty(),
+            fs.getPath(workingDir.newFile().getAbsolutePath()),
+            eventHandler,
+            ImmutableMap.of(),
+            "testRepo");
+
+    assertThat(times.get()).isEqualTo(4);
+    String content = new String(result.getInputStream().readAllBytes(), UTF_8);
+    assertThat(content).isEqualTo("content");
+  }
 }