Fix sideloaded subtitles

- Fix NPE issue in SingleSampleMediaPeriod.
- Delay handling of EOS in TextRenderer until the last
  subtitle is fully played out.

Issue: #1882

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=134979286

library/src/main/java/com/google/android/exoplayer2/source/SingleSampleMediaPeriod.java

@@ -41,7 +41,7 @@ import java.util.Arrays;
   /**
   /**
    * The initial size of the allocation used to hold the sample data.
    * The initial size of the allocation used to hold the sample data.
    */
    */
-  private static final int INITIAL_SAMPLE_SIZE = 1;
+  private static final int INITIAL_SAMPLE_SIZE = 1024;
 
 
   private final Uri uri;
   private final Uri uri;
   private final DataSource.Factory dataSourceFactory;
   private final DataSource.Factory dataSourceFactory;
@@ -71,7 +71,6 @@ import java.util.Arrays;
     tracks = new TrackGroupArray(new TrackGroup(format));
     tracks = new TrackGroupArray(new TrackGroup(format));
     sampleStreams = new ArrayList<>();
     sampleStreams = new ArrayList<>();
     loader = new Loader("Loader:SingleSampleMediaPeriod");
     loader = new Loader("Loader:SingleSampleMediaPeriod");
-    sampleData = new byte[INITIAL_SAMPLE_SIZE];
   }
   }
 
 
   public void release() {
   public void release() {
@@ -269,7 +268,9 @@ import java.util.Arrays;
         int result = 0;
         int result = 0;
         while (result != C.RESULT_END_OF_INPUT) {
         while (result != C.RESULT_END_OF_INPUT) {
           sampleSize += result;
           sampleSize += result;
-          if (sampleSize == sampleData.length) {
+          if (sampleData == null) {
+            sampleData = new byte[INITIAL_SAMPLE_SIZE];
+          } else if (sampleSize == sampleData.length) {
             sampleData = Arrays.copyOf(sampleData, sampleData.length * 2);
             sampleData = Arrays.copyOf(sampleData, sampleData.length * 2);
           }
           }
           result = dataSource.read(sampleData, sampleSize, sampleData.length - sampleSize);
           result = dataSource.read(sampleData, sampleSize, sampleData.length - sampleSize);

library/src/main/java/com/google/android/exoplayer2/text/TextRenderer.java

@@ -160,21 +160,27 @@ public final class TextRenderer extends BaseRenderer implements Callback {
       }
       }
     }
     }
 
 
-    if (nextSubtitle != null && nextSubtitle.timeUs <= positionUs) {
-      // Advance to the next subtitle. Sync the next event index and trigger an update.
-      if (subtitle != null) {
-        subtitle.release();
-      }
-      subtitle = nextSubtitle;
-      nextSubtitle = null;
-      if (subtitle.isEndOfStream()) {
-        outputStreamEnded = true;
-        subtitle.release();
-        subtitle = null;
-        return;
+    if (nextSubtitle != null) {
+      if (nextSubtitle.isEndOfStream()) {
+        if (!textRendererNeedsUpdate && getNextEventTime() == Long.MAX_VALUE) {
+          if (subtitle != null) {
+            subtitle.release();
+            subtitle = null;
+          }
+          nextSubtitle.release();
+          nextSubtitle = null;
+          outputStreamEnded = true;
+        }
+      } else if (nextSubtitle.timeUs <= positionUs) {
+        // Advance to the next subtitle. Sync the next event index and trigger an update.
+        if (subtitle != null) {
+          subtitle.release();
+        }
+        subtitle = nextSubtitle;
+        nextSubtitle = null;
+        nextSubtitleEventIndex = subtitle.getNextEventTimeIndex(positionUs);
+        textRendererNeedsUpdate = true;
       }
       }
-      nextSubtitleEventIndex = subtitle.getNextEventTimeIndex(positionUs);
-      textRendererNeedsUpdate = true;
     }
     }
 
 
     if (textRendererNeedsUpdate) {
     if (textRendererNeedsUpdate) {