File tar-1.27-revert-optimize-c-sparse.patch of Package tar.10815

---
 src/sparse.c |   54 ++++++++++++++++++++++++++----------------------------
 1 file changed, 26 insertions(+), 28 deletions(-)
--- a/src/sparse.c
+++ b/src/sparse.c
@@ -215,45 +215,43 @@ sparse_scan_file (struct tar_sparse_file
   struct tar_stat_info *st = file->stat_info;
   int fd = file->fd;
   char buffer[BLOCKSIZE];
-  size_t count = 0;
+  size_t count;
   off_t offset = 0;
   struct sp_array sp = {0, 0};
 
+  if (!lseek_or_error (file, 0))
+    return false;
+
   st->archive_file_size = 0;
 
-  if (ST_NBLOCKS (st->stat) == 0)
-    offset = st->stat.st_size;
-  else
-    {
-      if (!tar_sparse_scan (file, scan_begin, NULL))
-	return false;
+  if (!tar_sparse_scan (file, scan_begin, NULL))
+    return false;
 
-      while ((count = blocking_read (fd, buffer, sizeof buffer)) != 0
-	     && count != SAFE_READ_ERROR)
+  while ((count = blocking_read (fd, buffer, sizeof buffer)) != 0
+	 && count != SAFE_READ_ERROR)
+    {
+      /* Analyze the block.  */
+      if (zero_block_p (buffer, count))
 	{
-	  /* Analyze the block.  */
-	  if (zero_block_p (buffer, count))
-	    {
-	      if (sp.numbytes)
-		{
-		  sparse_add_map (st, &sp);
-		  sp.numbytes = 0;
-		  if (!tar_sparse_scan (file, scan_block, NULL))
-		    return false;
-		}
-	    }
-	  else
+	  if (sp.numbytes)
 	    {
-	      if (sp.numbytes == 0)
-		sp.offset = offset;
-	      sp.numbytes += count;
-	      st->archive_file_size += count;
-	      if (!tar_sparse_scan (file, scan_block, buffer))
+	      sparse_add_map (st, &sp);
+	      sp.numbytes = 0;
+	      if (!tar_sparse_scan (file, scan_block, NULL))
 		return false;
 	    }
-
-	  offset += count;
 	}
+      else
+	{
+	  if (sp.numbytes == 0)
+	    sp.offset = offset;
+	  sp.numbytes += count;
+	  st->archive_file_size += count;
+	  if (!tar_sparse_scan (file, scan_block, buffer))
+	    return false;
+	}
+
+      offset += count;
     }
 
   if (sp.numbytes == 0)