CodedOutputStream: avoid updating position to go beyond end of array.

In writeFixed32NoTag and writeFixed64NoTag

This is a partial roll-forward of cl/673588324.

PiperOrigin-RevId: 678435934

Author: mhansen

java/core/src/main/java/com/google/protobuf/CodedOutputStream.java

@@ -1346,6 +1346,7 @@ public final void writeUInt32NoTag(int value) throws IOException {
 
     @Override
     public final void writeFixed32NoTag(int value) throws IOException {
+      int position = this.position; // Perf: hoist field to register to avoid load/stores.
       try {
         buffer[position++] = (byte) (value & 0xFF);
         buffer[position++] = (byte) ((value >> 8) & 0xFF);
@@ -1355,6 +1356,7 @@ public final void writeFixed32NoTag(int value) throws IOException {
         throw new OutOfSpaceException(
             String.format("Pos: %d, limit: %d, len: %d", position, limit, 1), e);
       }
+      this.position = position; // Only update position if we stayed within the array bounds.
     }
 
     @Override
@@ -1389,6 +1391,7 @@ public final void writeUInt64NoTag(long value) throws IOException {
 
     @Override
     public final void writeFixed64NoTag(long value) throws IOException {
+      int position = this.position; // Perf: hoist field to register to avoid load/stores.
       try {
         buffer[position++] = (byte) ((int) (value) & 0xFF);
         buffer[position++] = (byte) ((int) (value >> 8) & 0xFF);
@@ -1402,6 +1405,7 @@ public final void writeFixed64NoTag(long value) throws IOException {
         throw new OutOfSpaceException(
             String.format("Pos: %d, limit: %d, len: %d", position, limit, 1), e);
       }
+      this.position = position; // Only update position if we stayed within the array bounds.
     }
 
     @Override

java/core/src/test/java/com/google/protobuf/CodedOutputStreamTest.java

@@ -294,12 +294,7 @@ public void testWriteFixed32NoTag_outOfBounds_throws() throws Exception {
     for (int i = 0; i < 4; i++) {
       Coder coder = outputType.newCoder(i);
       assertThrows(OutOfSpaceException.class, () -> coder.stream().writeFixed32NoTag(1));
-      // These OutputTypes are not behaving correctly yet.
-      if (outputType != OutputType.ARRAY
-          && outputType != OutputType.NIO_HEAP
-          && outputType != OutputType.NIO_HEAP_WITH_INITIAL_OFFSET) {
-        assertThat(coder.stream().spaceLeft()).isEqualTo(i);
-      }
+      assertThat(coder.stream().spaceLeft()).isEqualTo(i);
     }
   }
 
@@ -311,12 +306,7 @@ public void testWriteFixed64NoTag_outOfBounds_throws() throws Exception {
     for (int i = 0; i < 8; i++) {
       Coder coder = outputType.newCoder(i);
       assertThrows(OutOfSpaceException.class, () -> coder.stream().writeFixed64NoTag(1));
-      // These OutputTypes are not behaving correctly yet.
-      if (outputType != OutputType.ARRAY
-          && outputType != OutputType.NIO_HEAP
-          && outputType != OutputType.NIO_HEAP_WITH_INITIAL_OFFSET) {
-        assertThat(coder.stream().spaceLeft()).isEqualTo(i);
-      }
+      assertThat(coder.stream().spaceLeft()).isEqualTo(i);
     }
   }