Merge pull request #388 from esheldon/gzip-finalize

work around cfitsio bug creating HDU for lossless gzip

Author: esheldon

CHANGES.md

@@ -11,6 +11,8 @@ Bug Fixes
 
     - Bug not writing compression qlevel when it is set to None/0.0
       This was preventing lossless gzip compression
+    - work around cfitsio bug when creating HDU for lossless gzip compression,
+      reopen file instead of just an update hdu list
 
 version 1.2.0
 --------------

fitsio/fitslib.py

@@ -1040,9 +1040,13 @@ def create_image_hdu(self,
             extver=extver,
         )
 
-        # don't rebuild the whole list unless this is the first hdu
-        # to be created
-        self.update_hdu_list(rebuild=False)
+        if compress is not None and qlevel is None or qlevel == 0.0:
+            # work around bug in cfitso
+            self.reopen()
+        else:
+            # don't rebuild the whole list unless this is the first hdu
+            # to be created
+            self.update_hdu_list(rebuild=False)
 
     def _ensure_empty_image_ok(self):
         """

fitsio/tests/test_image_compression.py

@@ -98,12 +98,11 @@ def test_compressed_write_read(compress):
         'gzip_2_lossless',
     ]
 )
-def _test_compressed_write_read_fitsobj(compress):
+def test_compressed_write_read_fitsobj(compress):
     """
     Test writing and reading a rice compressed image
 
-    This one fails because the compressed data do not seem to be
-    finalized
+    In this version, keep the fits object open
     """
     nrows = 5
     ncols = 20
@@ -117,6 +116,7 @@ def _test_compressed_write_read_fitsobj(compress):
 
     if 'lossless' in compress:
         qlevel = None
+        # qlevel = 9999
     else:
         qlevel = 16
 
@@ -160,14 +160,6 @@ def _test_compressed_write_read_fitsobj(compress):
                         0.2,
                         "%s compressed images ('%s')" % (compress, dtype),
                     )
-                # else:
-                #     # for integers we have chosen a wide range of values, so
-                #     # there will be no quantization and we expect no
-                #     # information loss
-                #     compare_array(
-                #         data, rdata,
-                #         "%s compressed images ('%s')" % (compress, dtype)
-                #     )
 
         with FITS(fname) as fits:
             for ii in range(len(dtypes)):