Fix CacheDataSource trying to read more after EOS

setBytesRemaining() doesn't work when called after closeCurrentSource()

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=182999254

library/core/src/main/java/com/google/android/exoplayer2/upstream/cache/CacheDataSource.java

@@ -240,14 +240,12 @@ public final class CacheDataSource implements DataSource {
         if (bytesRemaining != C.LENGTH_UNSET) {
           bytesRemaining -= bytesRead;
         }
-      } else {
+      } else if (currentDataSpecLengthUnset) {
+        setBytesRemaining(0);
+      } else if (bytesRemaining > 0 || bytesRemaining == C.LENGTH_UNSET) {
         closeCurrentSource();
-        if (currentDataSpecLengthUnset) {
-          setBytesRemaining(0);
-        } else if (bytesRemaining > 0 || bytesRemaining == C.LENGTH_UNSET) {
-          openNextSource(false);
-          return read(buffer, offset, readLength);
-        }
+        openNextSource(false);
+        return read(buffer, offset, readLength);
       }
       return bytesRead;
     } catch (IOException e) {

library/core/src/test/java/com/google/android/exoplayer2/upstream/cache/CacheDataSourceTest.java

@@ -15,10 +15,8 @@
  */
 package com.google.android.exoplayer2.upstream.cache;
 
-import static com.google.android.exoplayer2.C.LENGTH_UNSET;
 import static com.google.android.exoplayer2.upstream.cache.CacheAsserts.assertCacheEmpty;
 import static com.google.common.truth.Truth.assertThat;
-import static com.google.common.truth.Truth.assertWithMessage;
 import static org.junit.Assert.fail;
 
 import android.net.Uri;
@@ -35,7 +33,6 @@ import java.util.Arrays;
 import java.util.NavigableSet;
 import org.junit.After;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.robolectric.RobolectricTestRunner;
@@ -97,10 +94,8 @@ public final class CacheDataSourceTest {
     assertCacheAndRead(false, true);
   }
 
-  // Disabled test as we don't support caching of definitely unknown length content
-  @Ignore
   @Test
-  public void disabledTestCacheAndReadUnboundedRequestUnknownLength() throws Exception {
+  public void testCacheAndReadUnboundedRequestUnknownLength() throws Exception {
     assertCacheAndRead(true, true);
   }
 
@@ -130,7 +125,7 @@ public final class CacheDataSourceTest {
     // Read partial at EOS but don't cross it so length is unknown
     CacheDataSource cacheDataSource = createCacheDataSource(false, true);
     assertReadData(cacheDataSource, true, TEST_DATA.length - 2, 2);
-    assertThat(cache.getContentLength(testDataKey)).isEqualTo(LENGTH_UNSET);
+    assertThat(cache.getContentLength(testDataKey)).isEqualTo(C.LENGTH_UNSET);
 
     // Now do an unbounded request for whole data. This will cause a bounded request from upstream.
     // End of data from upstream shouldn't be mixed up with EOS and cause length set wrong.
@@ -140,21 +135,48 @@ public final class CacheDataSourceTest {
     // Now the length set correctly do an unbounded request with offset
     assertThat(
             cacheDataSource.open(
-                new DataSpec(testDataUri, TEST_DATA.length - 2, LENGTH_UNSET, testDataKey)))
+                new DataSpec(testDataUri, TEST_DATA.length - 2, C.LENGTH_UNSET, testDataKey)))
         .isEqualTo(2);
 
     // An unbounded request with offset for not cached content
     assertThat(
             cacheDataSource.open(
-                new DataSpec(Uri.parse("notCachedUri"), TEST_DATA.length - 2, LENGTH_UNSET, null)))
-        .isEqualTo(LENGTH_UNSET);
+                new DataSpec(
+                    Uri.parse("notCachedUri"), TEST_DATA.length - 2, C.LENGTH_UNSET, null)))
+        .isEqualTo(C.LENGTH_UNSET);
+  }
+
+  @Test
+  public void testCantResolvedLengthContentReadInOneConnectionAndLengthIsResolved()
+      throws Exception {
+    FakeDataSource upstream = new FakeDataSource();
+    upstream
+        .getDataSet()
+        .newData(testDataUri)
+        .appendReadData(TEST_DATA)
+        .setSimulateUnknownLength(true);
+    CacheDataSource cacheDataSource = new CacheDataSource(cache, upstream, 0);
+
+    cacheDataSource.open(new DataSpec(testDataUri, 0, C.LENGTH_UNSET, testDataKey));
+    TestUtil.readToEnd(cacheDataSource);
+    cacheDataSource.close();
+
+    assertThat(upstream.getAndClearOpenedDataSpecs()).hasLength(1);
+    assertThat(cache.getContentLength(testDataKey)).isEqualTo(TEST_DATA.length);
   }
 
   @Test
   public void testIgnoreCacheForUnsetLengthRequests() throws Exception {
-    CacheDataSource cacheDataSource = createCacheDataSource(false, true,
-        CacheDataSource.FLAG_IGNORE_CACHE_FOR_UNSET_LENGTH_REQUESTS);
-    assertReadData(cacheDataSource, true, 0, C.LENGTH_UNSET);
+    FakeDataSource upstream = new FakeDataSource();
+    upstream.getDataSet().setData(testDataUri, TEST_DATA);
+    CacheDataSource cacheDataSource =
+        new CacheDataSource(
+            cache, upstream, CacheDataSource.FLAG_IGNORE_CACHE_FOR_UNSET_LENGTH_REQUESTS);
+
+    cacheDataSource.open(new DataSpec(testDataUri, 0, C.LENGTH_UNSET, testDataKey));
+    TestUtil.readToEnd(cacheDataSource);
+    cacheDataSource.close();
+
     assertThat(cache.getKeys()).isEmpty();
   }
 
@@ -347,10 +369,8 @@ public final class CacheDataSourceTest {
       boolean unboundedRequest, boolean unknownLength) throws IOException {
     int length = unboundedRequest ? C.LENGTH_UNSET : TEST_DATA.length;
     assertReadData(cacheDataSource, unknownLength, 0, length);
-    assertWithMessage(
-            "When the range specified, CacheDataSource doesn't reach EOS so shouldn't "
-                + "cache content length")
-        .that(cache.getContentLength(testDataKey))
+    // If !unboundedRequest, CacheDataSource doesn't reach EOS so shouldn't cache content length
+    assertThat(cache.getContentLength(testDataKey))
         .isEqualTo(!unboundedRequest ? C.LENGTH_UNSET : TEST_DATA.length);
   }
 
@@ -360,7 +380,9 @@ public final class CacheDataSourceTest {
     if (length != C.LENGTH_UNSET) {
       testDataLength = Math.min(testDataLength, length);
     }
-    DataSpec dataSpec = new DataSpec(testDataUri, position, length, testDataKey);
+    DataSpec dataSpec =
+        new DataSpec(
+            testDataUri, position, length, testDataKey, DataSpec.FLAG_ALLOW_CACHING_UNKNOWN_LENGTH);
     assertThat(cacheDataSource.open(dataSpec)).isEqualTo(unknownLength ? length : testDataLength);
     cacheDataSource.close();