1 files changed, 14 insertions, 2 deletions
diff --git a/java/src/main/java/com/google/protobuf/CodedInputStream.java b/java/src/main/java/com/google/protobuf/CodedInputStream.java
index 9125957d..f339c00e 100644
--- a/java/src/main/java/com/google/protobuf/CodedInputStream.java
+++ b/java/src/main/java/com/google/protobuf/CodedInputStream.java
@@ -467,7 +467,9 @@ public final class CodedInputStream {
   /**
    * The total number of bytes read before the current buffer.  The total
    * bytes read up to the current position can be computed as
-   * {@code totalBytesRetired + bufferPos}.
+   * {@code totalBytesRetired + bufferPos}.  This value may be negative if
+   * reading started in the middle of the current buffer (e.g. if the
+   * constructor that takes a byte array and an offset was used).
    */
   private int totalBytesRetired;
 
@@ -489,6 +491,7 @@ public final class CodedInputStream {
     this.buffer = buffer;
     bufferSize = off + len;
     bufferPos = off;
+    totalBytesRetired = -off;
     input = null;
   }
 
@@ -496,6 +499,7 @@ public final class CodedInputStream {
     buffer = new byte[BUFFER_SIZE];
     bufferSize = 0;
     bufferPos = 0;
+    totalBytesRetired = 0;
     this.input = input;
   }
 
@@ -546,7 +550,7 @@ public final class CodedInputStream {
    * Resets the current size counter to zero (see {@link #setSizeLimit(int)}).
    */
   public void resetSizeCounter() {
-    totalBytesRetired = 0;
+    totalBytesRetired = -bufferPos;
   }
 
   /**
@@ -616,6 +620,14 @@ public final class CodedInputStream {
   }
 
   /**
+   * The total bytes read up to the current position. Calling
+   * {@link #resetSizeCounter()} resets this value to zero.
+   */
+  public int getTotalBytesRead() {
+      return totalBytesRetired + bufferPos;
+  }
+
+  /**
    * Called with {@code this.buffer} is empty to read more bytes from the
    * input.  If {@code mustSucceed} is true, refillBuffer() gurantees that
    * either there will be at least one byte in the buffer when it returns