From 958331a8ea9f6df8d7e292440c99929b1c307042 Mon Sep 17 00:00:00 2001
From: Cody Henthorne <cody@signal.org>
Date: Tue, 8 Jun 2021 16:46:01 -0400
Subject: [PATCH] Fix bug with APNGParser over reading larger files and
 invalidating the stream.

---
 .../glide/cache/ApngStreamCacheDecoder.java   |  5 +++-
 .../securesms/glide/cache/LimitedReader.kt    | 27 +++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 app/src/main/java/org/thoughtcrime/securesms/glide/cache/LimitedReader.kt

diff --git a/app/src/main/java/org/thoughtcrime/securesms/glide/cache/ApngStreamCacheDecoder.java b/app/src/main/java/org/thoughtcrime/securesms/glide/cache/ApngStreamCacheDecoder.java
index fdce779f78..37954ba1ee 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/glide/cache/ApngStreamCacheDecoder.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/glide/cache/ApngStreamCacheDecoder.java
@@ -18,6 +18,9 @@ import java.nio.ByteBuffer;
 
 public class ApngStreamCacheDecoder implements ResourceDecoder<InputStream, APNGDecoder> {
 
+  /** Set to match {@link com.bumptech.glide.load.data.InputStreamRewinder}'s read limit */
+  private static final int READ_LIMIT = 5 * 1024 * 1024;
+
   private final ResourceDecoder<ByteBuffer, APNGDecoder> byteBufferDecoder;
 
   public ApngStreamCacheDecoder(ResourceDecoder<ByteBuffer, APNGDecoder> byteBufferDecoder) {
@@ -27,7 +30,7 @@ public class ApngStreamCacheDecoder implements ResourceDecoder<InputStream, APNG
   @Override
   public boolean handles(@NonNull InputStream source, @NonNull Options options) {
     if (options.get(ApngOptions.ANIMATE)) {
-      return APNGParser.isAPNG(new StreamReader(source));
+      return APNGParser.isAPNG(new LimitedReader(new StreamReader(source), READ_LIMIT));
     } else {
       return false;
     }
diff --git a/app/src/main/java/org/thoughtcrime/securesms/glide/cache/LimitedReader.kt b/app/src/main/java/org/thoughtcrime/securesms/glide/cache/LimitedReader.kt
new file mode 100644
index 0000000000..51abb3d79a
--- /dev/null
+++ b/app/src/main/java/org/thoughtcrime/securesms/glide/cache/LimitedReader.kt
@@ -0,0 +1,27 @@
+package org.thoughtcrime.securesms.glide.cache
+
+import org.signal.glide.common.io.Reader
+import java.io.IOException
+import kotlin.jvm.Throws
+
+/**
+ * Restrict the number of bytes that can be read to prevent breaking the input stream in Glide's
+ * eyes.
+ */
+class LimitedReader(private val reader: Reader, private val readLimit: Int) : Reader by reader {
+  @Throws(IOException::class)
+  override fun read(buffer: ByteArray?, start: Int, byteCount: Int): Int {
+    if (position() + byteCount >= readLimit) {
+      throw IOException("Read limit exceeded")
+    }
+    return reader.read(buffer, start, byteCount)
+  }
+
+  @Throws(IOException::class)
+  override fun skip(total: Long): Long {
+    if (position() + total >= readLimit) {
+      throw IOException("Read limit exceeded")
+    }
+    return reader.skip(total)
+  }
+}