XAR reader: initialize file_queue with 0 and memcpy() if allocated only

Fixes #1338

1 files changed, 13 insertions, 4 deletions

diff --git a/libarchive/archive_read_support_format_xar.c b/libarchive/archive_read_support_format_xar.c
index 7f8be398..503ff58b 100644
--- a/libarchive/archive_read_support_format_xar.c
+++ b/libarchive/archive_read_support_format_xar.c
@@ -458,6 +458,11 @@ archive_read_support_format_xar(struct archive *_a)
 		return (ARCHIVE_FATAL);
 	}
 
+	/* initialize xar->file_queue */
+	xar->file_queue.allocated = 0;
+	xar->file_queue.used = 0;
+	xar->file_queue.files = NULL;
+
 	r = __archive_read_register_format(a,
 	    xar,
 	    "xar",
@@ -1221,10 +1226,12 @@ heap_add_entry(struct archive_read *a,
 	/* Expand our pending files list as necessary. */
 	if (heap->used >= heap->allocated) {
 		struct xar_file **new_pending_files;
-		int new_size = heap->allocated * 2;
+		int new_size;
 
 		if (heap->allocated < 1024)
 			new_size = 1024;
+		else
+			new_size = heap->allocated * 2;
 		/* Overflow might keep us from growing the list. */
 		if (new_size <= heap->allocated) {
 			archive_set_error(&a->archive,
@@ -1238,9 +1245,11 @@ heap_add_entry(struct archive_read *a,
 			    ENOMEM, "Out of memory");
 			return (ARCHIVE_FATAL);
 		}
-		memcpy(new_pending_files, heap->files,
-		    heap->allocated * sizeof(new_pending_files[0]));
-		free(heap->files);
+		if (heap->allocated) {
+			memcpy(new_pending_files, heap->files,
+			    heap->allocated * sizeof(new_pending_files[0]));
+			free(heap->files);
+		}
 		heap->files = new_pending_files;
 		heap->allocated = new_size;
 	}