Suppress go/nullness warnings caused by Matcher#group(String) and Matcher#group(int)

This is required to align google3's stub (currently marked non-null) with Checker Framework's.

More information: go/matcher-nullness-lsc

Tested:
    TAP train for global presubmit queue
    http://test/OCL:303344687:BASE:303326748:1585344475427:29edc250
PiperOrigin-RevId: 303709053

extensions/cronet/src/main/java/com/google/android/exoplayer2/ext/cronet/CronetDataSource.java

@@ -818,6 +818,8 @@ public class CronetDataSource extends BaseDataSource implements HttpDataSource {
       Matcher matcher = CONTENT_RANGE_HEADER_PATTERN.matcher(contentRangeHeader);
       if (matcher.find()) {
         try {
+          // incompatible types in argument.
+          @SuppressWarnings("nullness:argument.type.incompatible")
           long contentLengthFromRange =
               Long.parseLong(matcher.group(2)) - Long.parseLong(matcher.group(1)) + 1;
           if (contentLength < 0) {

library/common/src/main/java/com/google/android/exoplayer2/util/Util.java

@@ -1021,13 +1021,16 @@ public final class Util {
   }
 
   /**
-   * Parses an xs:dateTime attribute value, returning the parsed timestamp in milliseconds since
+   * Parses an xs:dateTime attribute value, returning the parsed timestamp in milliseconds since the
-   * the epoch.
+   * epoch.
    *
    * @param value The attribute value to decode.
    * @return The parsed timestamp in milliseconds since the epoch.
    * @throws ParserException if an error occurs parsing the dateTime attribute value.
    */
+  // incompatible types in argument.
+  // dereference of possibly-null reference matcher.group(9)
+  @SuppressWarnings({"nullness:argument.type.incompatible", "nullness:dereference.of.nullable"})
   public static long parseXsDateTime(String value) throws ParserException {
     Matcher matcher = XS_DATE_TIME_PATTERN.matcher(value);
     if (!matcher.matches()) {
@@ -1719,6 +1722,8 @@ public final class Util {
     Matcher matcher = ESCAPED_CHARACTER_PATTERN.matcher(fileName);
     int startOfNotEscaped = 0;
     while (percentCharacterCount > 0 && matcher.find()) {
+      // incompatible types in argument.
+      @SuppressWarnings("nullness:argument.type.incompatible")
       char unescapedCharacter = (char) Integer.parseInt(matcher.group(1), 16);
       builder.append(fileName, startOfNotEscaped, matcher.start()).append(unescapedCharacter);
       startOfNotEscaped = matcher.end();

library/core/src/main/java/com/google/android/exoplayer2/metadata/icy/IcyDecoder.java

@@ -44,6 +44,8 @@ public final class IcyDecoder implements MetadataDecoder {
     iso88591Decoder = Charset.forName(C.ISO88591_NAME).newDecoder();
   }
 
+  // switching on a possibly-null value (key)
+  @SuppressWarnings("nullness:switching.nullable")
   @Override
   public Metadata decode(MetadataInputBuffer inputBuffer) {
     ByteBuffer buffer = Assertions.checkNotNull(inputBuffer.data);

library/core/src/main/java/com/google/android/exoplayer2/text/ssa/SsaStyle.java

@@ -229,6 +229,8 @@ import java.util.regex.Pattern;
       while (matcher.find()) {
         String braceContents = matcher.group(1);
         try {
+          // incompatible types in argument.
+          @SuppressWarnings("nullness:argument.type.incompatible")
           PointF parsedPosition = parsePosition(braceContents);
           if (parsedPosition != null) {
             position = parsedPosition;
@@ -237,7 +239,10 @@ import java.util.regex.Pattern;
           // Ignore invalid \pos() or \move() function.
         }
         try {
-          @SsaAlignment int parsedAlignment = parseAlignmentOverride(braceContents);
+          // incompatible types in argument.
+          @SuppressWarnings("nullness:argument.type.incompatible")
+          @SsaAlignment
+          int parsedAlignment = parseAlignmentOverride(braceContents);
           if (parsedAlignment != SSA_ALIGNMENT_UNKNOWN) {
             alignment = parsedAlignment;
           }
@@ -292,6 +297,8 @@ import java.util.regex.Pattern;
           Float.parseFloat(Assertions.checkNotNull(y).trim()));
     }
 
+    // incompatible types in argument.
+    @SuppressWarnings("nullness:argument.type.incompatible")
     @SsaAlignment
     private static int parseAlignmentOverride(String braceContents) {
       Matcher matcher = ALIGNMENT_OVERRIDE_PATTERN.matcher(braceContents);

library/core/src/main/java/com/google/android/exoplayer2/text/subrip/SubripDecoder.java

@@ -230,6 +230,8 @@ public final class SubripDecoder extends SimpleSubtitleDecoder {
         Cue.DIMEN_UNSET);
   }
 
+  // incompatible types in argument.
+  @SuppressWarnings("nullness:argument.type.incompatible")
   private static long parseTimecode(Matcher matcher, int groupOffset) {
     @Nullable String hours = matcher.group(groupOffset + 1);
     long timestampMs = hours != null ? Long.parseLong(hours) * 60 * 60 * 1000 : 0;

library/core/src/main/java/com/google/android/exoplayer2/text/webvtt/CssParser.java

@@ -322,9 +322,11 @@ import java.util.regex.Pattern;
   }
 
   /**
-   * Sets the target of a {@link WebvttCssStyle} by splitting a selector of the form
+   * Sets the target of a {@link WebvttCssStyle} by splitting a selector of the form {@code
-   * {@code ::cue(tag#id.class1.class2[voice="someone"]}, where every element is optional.
+   * ::cue(tag#id.class1.class2[voice="someone"]}, where every element is optional.
    */
+  // incompatible types in argument.
+  @SuppressWarnings("nullness:argument.type.incompatible")
   private void applySelectorToStyle(WebvttCssStyle style, String selector) {
     if ("".equals(selector)) {
       return; // Universal selector.

library/core/src/main/java/com/google/android/exoplayer2/text/webvtt/WebvttCueParser.java

@@ -322,6 +322,8 @@ public final class WebvttCueParser {
 
   // Internal methods
 
+  // incompatible types in argument.
+  @SuppressWarnings("nullness:argument.type.incompatible")
   @Nullable
   private static WebvttCueInfo parseCue(
       @Nullable String id,
@@ -354,6 +356,8 @@ public final class WebvttCueParser {
     return builder.build();
   }
 
+  // incompatible types in argument.
+  @SuppressWarnings("nullness:argument.type.incompatible")
   private static void parseCueSettingsList(String cueSettingsList, WebvttCueInfoBuilder builder) {
     // Parse the cue settings list.
     Matcher cueSettingMatcher = CUE_SETTING_PATTERN.matcher(cueSettingsList);

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

@@ -113,6 +113,8 @@ import java.util.regex.Pattern;
    * @return The span, or null if the file name is not correctly formatted, or if the id is not
    *     present in the content index, or if the length is 0.
    */
+  // incompatible types in argument.
+  @SuppressWarnings("nullness:argument.type.incompatible")
   @Nullable
   public static SimpleCacheSpan createCacheEntry(
       File file, long length, long lastTouchTimestamp, CachedContentIndex index) {
@@ -131,6 +133,8 @@ import java.util.regex.Pattern;
       return null;
     }
 
+    // incompatible types in argument.
+    @SuppressWarnings("nullness:argument.type.incompatible")
     int id = Integer.parseInt(matcher.group(1));
     @Nullable String key = index.getKeyForId(id);
     if (key == null) {
@@ -144,6 +148,8 @@ import java.util.regex.Pattern;
       return null;
     }
 
+    // incompatible types in argument.
+    @SuppressWarnings("nullness:argument.type.incompatible")
     long position = Long.parseLong(matcher.group(2));
     if (lastTouchTimestamp == C.TIME_UNSET) {
       lastTouchTimestamp = Long.parseLong(matcher.group(3));
@@ -159,6 +165,8 @@ import java.util.regex.Pattern;
    * @return Upgraded cache file or {@code null} if the file name is not correctly formatted or the
    *     file can not be renamed.
    */
+  // incompatible types in argument.
+  @SuppressWarnings("nullness:argument.type.incompatible")
   @Nullable
   private static File upgradeFile(File file, CachedContentIndex index) {
     @Nullable String key = null;
@@ -177,6 +185,8 @@ import java.util.regex.Pattern;
       return null;
     }
 
+    // incompatible types in argument.
+    @SuppressWarnings("nullness:argument.type.incompatible")
     File newCacheFile =
         getCacheFile(
             Assertions.checkStateNotNull(file.getParentFile()),

library/core/src/main/java/com/google/android/exoplayer2/util/ColorParser.java

@@ -63,6 +63,8 @@ public final class ColorParser {
     return parseColorInternal(colorExpression, true);
   }
 
+  // incompatible types in argument.
+  @SuppressWarnings("nullness:argument.type.incompatible")
   private static int parseColorInternal(String colorExpression, boolean alphaHasFloatFormat) {
     Assertions.checkArgument(!TextUtils.isEmpty(colorExpression));
     colorExpression = colorExpression.replace(" ", "");

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/WebvttExtractor.java

@@ -133,6 +133,8 @@ public final class WebvttExtractor implements Extractor {
     return Extractor.RESULT_END_OF_INPUT;
   }
 
+  // incompatible types in argument.
+  @SuppressWarnings("nullness:argument.type.incompatible")
   @RequiresNonNull("output")
   private void processSample() throws ParserException {
     ParsableByteArray webvttData = new ParsableByteArray(sampleData);
@@ -170,6 +172,8 @@ public final class WebvttExtractor implements Extractor {
       return;
     }
 
+    // incompatible types in argument.
+    @SuppressWarnings("nullness:argument.type.incompatible")
     long firstCueTimeUs = WebvttParserUtil.parseTimestampUs(cueHeaderMatcher.group(1));
     long sampleTimeUs = timestampAdjuster.adjustTsTimestamp(
         TimestampAdjuster.usToPts(firstCueTimeUs + tsTimestampUs - vttTimestampUs));

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/playlist/HlsPlaylistParser.java

@@ -823,6 +823,8 @@ public final class HlsPlaylistParser implements ParsingLoadable.Parser<HlsPlayli
     return Integer.parseInt(parseStringAttr(line, pattern, Collections.emptyMap()));
   }
 
+  // incompatible types in argument.
+  @SuppressWarnings("nullness:argument.type.incompatible")
   private static int parseOptionalIntAttr(String line, Pattern pattern, int defaultValue) {
     Matcher matcher = pattern.matcher(line);
     if (matcher.find()) {
@@ -855,6 +857,8 @@ public final class HlsPlaylistParser implements ParsingLoadable.Parser<HlsPlayli
     return parseOptionalStringAttr(line, pattern, null, variableDefinitions);
   }
 
+  // incompatible types in return.
+  @SuppressWarnings("nullness:return.type.incompatible")
   private static @PolyNull String parseOptionalStringAttr(
       String line,
       Pattern pattern,
@@ -885,6 +889,8 @@ public final class HlsPlaylistParser implements ParsingLoadable.Parser<HlsPlayli
     return stringWithReplacements.toString();
   }
 
+  // dereference of possibly-null reference matcher.group(1)
+  @SuppressWarnings("nullness:dereference.of.nullable")
   private static boolean parseOptionalBooleanAttribute(
       String line, Pattern pattern, boolean defaultValue) {
     Matcher matcher = pattern.matcher(line);