From fff7b8079a1d3cc8340274aff7df8cd3dcb7e8d3 Mon Sep 17 00:00:00 2001
From: ibaker <ibaker@google.com>
Date: Fri, 16 Apr 2021 11:45:36 +0100
Subject: [PATCH] Replace Util.toUpperInvariant() with Ascii.toUpperCase()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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Even when fixed to the US locale (and thus avoiding surprising behaviour
in e.g. Turkish locale with "i" and "I") there are unexpected behaviours
when upper and lower casing non-ASCII characters.

For example it's sometimes not symmetric, e.g.:
"ẞ".toLowerCase() -> "ß"
"ß".toUpperCase() -> "SS"

In all the ExoPlayer usages we are either dealing with known-ASCII
strings (e.g. MIME types) or comparing against ASCII constant strings
anyway, so it seems easier to just use Guava's ASCII-only class in these
cases.

Util.toUpperInvariant() is null-tolerant, while Ascii.toLowercase() is
not. Most usages in this change are clearly non-null. The BandwidthMeter
usages aren't annotated @Nullable, but the current code *would* work if
countryCode was null in both cases. These methods will now throw NPE if
they're passed null.

PiperOrigin-RevId: 368816287
---
 .../com/google/android/exoplayer2/util/Util.java   | 14 ++------------
 .../exoplayer2/upstream/DefaultBandwidthMeter.java |  3 ++-
 .../hls/playlist/HlsMediaPlaylistParserTest.java   |  4 ++--
 3 files changed, 6 insertions(+), 15 deletions(-)

diff --git a/library/common/src/main/java/com/google/android/exoplayer2/util/Util.java b/library/common/src/main/java/com/google/android/exoplayer2/util/Util.java
index 2d643673be..2e3e3d8567 100644
--- a/library/common/src/main/java/com/google/android/exoplayer2/util/Util.java
+++ b/library/common/src/main/java/com/google/android/exoplayer2/util/Util.java
@@ -760,16 +760,6 @@ public final class Util {
     return c == '\n' || c == '\r';
   }
 
-  /**
-   * Converts text to upper case using {@link Locale#US}.
-   *
-   * @param text The text to convert.
-   * @return The upper case text, or null if {@code text} is null.
-   */
-  public static @PolyNull String toUpperInvariant(@PolyNull String text) {
-    return text == null ? text : text.toUpperCase(Locale.US);
-  }
-
   /**
    * Formats a string using {@link Locale#US}.
    *
@@ -2151,11 +2141,11 @@ public final class Util {
       if (telephonyManager != null) {
         String countryCode = telephonyManager.getNetworkCountryIso();
         if (!TextUtils.isEmpty(countryCode)) {
-          return toUpperInvariant(countryCode);
+          return Ascii.toUpperCase(countryCode);
         }
       }
     }
-    return toUpperInvariant(Locale.getDefault().getCountry());
+    return Ascii.toUpperCase(Locale.getDefault().getCountry());
   }
 
   /**
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/DefaultBandwidthMeter.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/DefaultBandwidthMeter.java
index 8232d90668..1c0b3f2642 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/DefaultBandwidthMeter.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/DefaultBandwidthMeter.java
@@ -25,6 +25,7 @@ import com.google.android.exoplayer2.util.Clock;
 import com.google.android.exoplayer2.util.NetworkTypeObserver;
 import com.google.android.exoplayer2.util.SlidingPercentile;
 import com.google.android.exoplayer2.util.Util;
+import com.google.common.base.Ascii;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableListMultimap;
 import com.google.common.collect.ImmutableMap;
@@ -170,7 +171,7 @@ public final class DefaultBandwidthMeter implements BandwidthMeter, TransferList
      */
     public Builder setInitialBitrateEstimate(String countryCode) {
       initialBitrateEstimates =
-          getInitialBitrateEstimatesForCountry(Util.toUpperInvariant(countryCode));
+          getInitialBitrateEstimatesForCountry(Ascii.toUpperCase(countryCode));
       return this;
     }
 
diff --git a/library/hls/src/test/java/com/google/android/exoplayer2/source/hls/playlist/HlsMediaPlaylistParserTest.java b/library/hls/src/test/java/com/google/android/exoplayer2/source/hls/playlist/HlsMediaPlaylistParserTest.java
index 48f6a06b14..7cc9a75c1a 100644
--- a/library/hls/src/test/java/com/google/android/exoplayer2/source/hls/playlist/HlsMediaPlaylistParserTest.java
+++ b/library/hls/src/test/java/com/google/android/exoplayer2/source/hls/playlist/HlsMediaPlaylistParserTest.java
@@ -135,7 +135,7 @@ public class HlsMediaPlaylistParserTest {
         .isEqualTo("https://priv.example.com/key.php?r=2682");
     // 0xA7A == 2682.
     assertThat(segment.encryptionIV).isNotNull();
-    assertThat(Util.toUpperInvariant(segment.encryptionIV)).isEqualTo("A7A");
+    assertThat(segment.encryptionIV).ignoringCase().isEqualTo("A7A");
     assertThat(segment.byteRangeLength).isEqualTo(51740);
     assertThat(segment.byteRangeOffset).isEqualTo(2147586650L);
     assertThat(segment.url).isEqualTo("https://priv.example.com/fileSequence2682.ts");
@@ -148,7 +148,7 @@ public class HlsMediaPlaylistParserTest {
         .isEqualTo("https://priv.example.com/key.php?r=2682");
     // 0xA7B == 2683.
     assertThat(segment.encryptionIV).isNotNull();
-    assertThat(Util.toUpperInvariant(segment.encryptionIV)).isEqualTo("A7B");
+    assertThat(segment.encryptionIV).ignoringCase().isEqualTo("A7B");
     assertThat(segment.byteRangeLength).isEqualTo(C.LENGTH_UNSET);
     assertThat(segment.byteRangeOffset).isEqualTo(0);
     assertThat(segment.url).isEqualTo("https://priv.example.com/fileSequence2683.ts");