nansencenter#525: history is cut by gdal CreateCopy. This needs to be…

… overridden.

nansat/exporter.py

@@ -129,25 +129,29 @@ def export(self, filename='', bands=None, rm_metadata=None, add_geolocation=True
             # Rename variable names to get rid of the band numbers
             self.rename_variables(filename)
             # Rename attributes to get rid of "GDAL_" added by gdal
-            self.rename_attributes(filename)
+            self.correct_attributes(filename, history=self.vrt.dataset.GetMetadata()['history'])
 
         self.logger.debug('Export - OK!')
 
     @staticmethod
-    def rename_attributes(filename):
+    def correct_attributes(filename, history=None):
         """ Rename global attributes to get rid of the "GDAL_"-string
-        added by gdal.
+        added by gdal, remove attributes added by gdal that are
+        already present in the Nansat object, and correct the history
+        attribute (the latter may be reduced in length because
+        gdal.GetDriverByName(driver).CreateCopy limits the string
+        lenght to 161 characters).
         """
         GDAL = "GDAL_"
         del_attrs = []
         rename_attrs = []
         # Open new file to edit attribute names
         ds = Dataset(filename, 'r+')
         """ The netcdf driver adds the Conventions attribute with
-        value CF-1.5. This may be wrong, so it is better to use the
-        Conventions metadata from the Nansat object. Other attributes
-        added by gdal that are already present in Nansat, should also
-        be deleted."""
+        value CF-1.5. This in most cases wrong, so it is better to use
+        the Conventions metadata from the Nansat object. Other
+        attributes added by gdal that are already present in Nansat,
+        should also be deleted."""
         for attr in ds.ncattrs():
             if GDAL in attr:
                 if attr.replace(GDAL, "") in ds.ncattrs():
@@ -163,6 +167,9 @@ def rename_attributes(filename):
         # Rename attributes:
         for attr in rename_attrs:
             ds.renameAttribute(attr, attr.replace(GDAL, ""))
+        # Correct the history
+        if history is not None:
+            ds.history = history
         ds.close()
 
     @staticmethod