When dealing with multi-stage decompression we want to specify the
target file name lest we just overload the cache name. It also allows
for something is little more friendly than the cache hash.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 tests/functional/qemu_test/testcase.py | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tests/functional/qemu_test/testcase.py b/tests/functional/qemu_test/testcase.py
index c2c916f6077..eaec1bea138 100644
--- a/tests/functional/qemu_test/testcase.py
+++ b/tests/functional/qemu_test/testcase.py
@@ -35,7 +35,7 @@
 
 class QemuBaseTest(unittest.TestCase):
 
-    def uncompress(self, compressed, format=None):
+    def uncompress(self, compressed, target=None, format=None):
         '''
         @params compressed: filename, Asset, or file-like object to uncompress
         @params format: optional compression format (gzip, lzma)
@@ -52,8 +52,11 @@ def uncompress(self, compressed, format=None):
         if isinstance(compressed, Asset):
             compressed.fetch()
 
-        (name, _ext) = os.path.splitext(str(compressed))
-        uncompressed = self.scratch_file(os.path.basename(name))
+        if target is not None:
+            uncompressed = self.scratch_file(target)
+        else:
+            (name, _ext) = os.path.splitext(str(compressed))
+            uncompressed = self.scratch_file(os.path.basename(name))
 
         uncompress(compressed, uncompressed, format)
 
-- 
2.47.3