in FLAC__stream_encoder_set_metadata(), copy the metadata array of pointers...

in FLAC__stream_encoder_set_metadata(), copy the metadata array of pointers instead of requiring the caller to keep it until initialization; the objects themselves are still owned by caller

include/FLAC/stream_encoder.h

@@ -1104,12 +1104,12 @@ FLAC_API FLAC__bool FLAC__stream_encoder_set_total_samples_estimate(FLAC__Stream
  *  the encoder may need to change the \a is_last flag inside them, and
  *  in some cases update seek point offsets.  Otherwise, the encoder will
  *  not modify or free the blocks.  It is up to the caller to free the
- *  metadata blocks after encoding.
+ *  metadata blocks after encoding finishes.
  *
  * \note
- * The encoder stores only the \a metadata pointer; the passed-in array
- * must survive at least until after FLAC__stream_encoder_init_*() returns.
- * Do not modify the array or free the blocks until then.
+ * The encoder stores only copies of the pointers in the \a metadata array;
+ * the metadata blocks themselves must survive at least until after
+ * FLAC__stream_encoder_finish() returns.  Do not free the blocks until then.
  *
  * \note
  * The STREAMINFO block is always written and no STREAMINFO block may

src/libFLAC/stream_encoder.c

@@ -1708,8 +1708,24 @@ FLAC_API FLAC__bool FLAC__stream_encoder_set_metadata(FLAC__StreamEncoder *encod
 	FLAC__ASSERT(0 != encoder->protected_);
 	if(encoder->protected_->state != FLAC__STREAM_ENCODER_UNINITIALIZED)
 		return false;
-	encoder->protected_->metadata = metadata;
-	encoder->protected_->num_metadata_blocks = num_blocks;
+	if(0 == metadata)
+		num_blocks = 0;
+	if(0 == num_blocks)
+		metadata = 0;
+	/* realloc() does not do exactly what we want so... */
+	if(encoder->protected_->metadata) {
+		free(encoder->protected_->metadata);
+		encoder->protected_->metadata = 0;
+		encoder->protected_->num_metadata_blocks = 0;
+	}
+	if(num_blocks) {
+		FLAC__StreamMetadata **m;
+		if(0 == (m = (FLAC__StreamMetadata**)malloc(sizeof(m[0]) * num_blocks)))
+			return false;
+		memcpy(m, metadata, sizeof(m[0]) * num_blocks);
+		encoder->protected_->metadata = m;
+		encoder->protected_->num_metadata_blocks = num_blocks;
+	}
 #if FLAC__HAS_OGG
 	if(!FLAC__ogg_encoder_aspect_set_num_metadata(&encoder->protected_->ogg_encoder_aspect, num_blocks))
 		return false;
@@ -2367,6 +2383,11 @@ void free_(FLAC__StreamEncoder *encoder)
 	unsigned i, channel;
 
 	FLAC__ASSERT(0 != encoder);
+	if(encoder->protected_->metadata) {
+		free(encoder->protected_->metadata);
+		encoder->protected_->metadata = 0;
+		encoder->protected_->num_metadata_blocks = 0;
+	}
 	for(i = 0; i < encoder->protected_->channels; i++) {
 		if(0 != encoder->private_->integer_signal_unaligned[i]) {
 			free(encoder->private_->integer_signal_unaligned[i]);