Fix file URI retrieval to fix gzipped ASDF-in-FITS bug

CHANGES.rst

@@ -8,6 +8,9 @@
 1.4.0 (unreleased)
 ------------------
 
+- Improve the way URIs are detected for ASDF-in-FITS files in order to fix bug
+  with reading gzipped ASDF-in-FITS files. [#416]
+
 - Explicitly disallow access to entire tree for ASDF file objects that have
   been closed. [#407]
 

asdf/fits_embed.py

@@ -195,17 +195,15 @@ def open(cls, fd, uri=None, validate_checksums=False, extensions=None,
         if isinstance(fd, fits.hdu.hdulist.HDUList):
             hdulist = fd
         else:
-            file_obj = generic_io.get_file(fd, uri=uri)
-            uri = file_obj._uri if uri is None and file_obj._uri else ''
+            uri = generic_io.get_uri(fd)
             try:
-                hdulist = fits.open(file_obj)
+                hdulist = fits.open(fd)
                 # Since we created this HDUList object, we need to be
                 # responsible for cleaning up upon close() or __exit__
                 close_hdulist = True
             except IOError:
-                file_obj.close()
                 msg = "Failed to parse given file '{}'. Is it FITS?"
-                raise ValueError(msg.format(file_obj.uri))
+                raise ValueError(msg.format(uri))
 
         self = cls(hdulist, uri=uri, extensions=extensions,
                    ignore_version_mismatch=ignore_version_mismatch,

asdf/generic_io.py

@@ -34,7 +34,7 @@
 from . import util
 
 
-__all__ = ['get_file', 'resolve_uri', 'relative_uri']
+__all__ = ['get_file', 'get_uri', 'resolve_uri', 'relative_uri']
 
 
 _local_file_schemes = ['', 'file']
@@ -1102,6 +1102,22 @@ def _make_http_connection(init, mode, uri=None):
     return HTTPConnection(connection, size, parsed.path, uri or init,
                           first_chunk)
 
+def get_uri(file_obj):
+    """
+    Returns the uri of the given file object
+
+    Parameters
+    ----------
+    uri : object
+    """
+    if isinstance(file_obj, six.string_types):
+        return file_obj
+    if isinstance(file_obj, GenericFile):
+        return file_obj.uri
+
+    # A catch-all for types from Python's io module that have names
+    return getattr(file_obj, 'name', '')
+
 
 def get_file(init, mode='r', uri=None):
     """

asdf/tests/test_fits_embed.py

@@ -252,7 +252,7 @@ def test_version_mismatch_file():
     assert len(w) == 1
     assert str(w[0].message) == (
         "'tag:stsci.edu:asdf/core/complex' with version 7.0.0 found in file "
-        "'file://{}', but latest supported version is 1.0.0".format(testfile))
+        "'{}', but latest supported version is 1.0.0".format(testfile))
 
     # Make sure warning does not occur when warning is ignored (default)
     with catch_warnings() as w:
@@ -267,7 +267,7 @@ def test_version_mismatch_file():
     assert len(w) == 1
     assert str(w[0].message) == (
         "'tag:stsci.edu:asdf/core/complex' with version 7.0.0 found in file "
-        "'file://{}', but latest supported version is 1.0.0".format(testfile))
+        "'{}', but latest supported version is 1.0.0".format(testfile))
 
     # Make sure warning does not occur when warning is ignored (default)
     with catch_warnings() as w: