filemap: calculate dst size correctly

Fixed calculation of the dst file size using skip, seek and
length parameters. Current code does it incorrectly which
causes sparse_copy API to create unnecessary big output files.

(From OE-Core rev: e6d709a6382e4b913612f597e66ad07b0e351d5f)

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/scripts/lib/wic/filemap.py b/scripts/lib/wic/filemap.py
index 764dbbe588..6d11355a18 100644
--- a/scripts/lib/wic/filemap.py
+++ b/scripts/lib/wic/filemap.py
@@ -549,7 +549,11 @@ def sparse_copy(src_fname, dst_fname, skip=0, seek=0,
         dst_file = open(dst_fname, 'r+b')
     except IOError:
         dst_file = open(dst_fname, 'wb')
-        dst_file.truncate(os.path.getsize(src_fname))
+        if length:
+            dst_size = length + seek
+        else:
+            dst_size = os.path.getsize(src_fname) + seek - skip
+        dst_file.truncate(dst_size)
 
     written = 0
     for first, last in fmap.get_mapped_ranges(0, fmap.blocks_cnt):