changelog: try iso8859-1 when utf-8 fails

Fall back to iso8859-1 when opening the changelog. Helps when importing
old versions.

Closes: #900841
Signed-off-by: Guido Günther <[email protected]>

Author: gsliepen

gbp/deb/changelog.py

@@ -128,8 +128,12 @@ def _parse(self):
         self._cp = cp
 
     def _read(self):
-        with open(self.filename, encoding='utf-8') as f:
-            self._contents = f.read()
+        try:
+            with open(self.filename, encoding='utf-8') as f:
+                self._contents = f.read()
+        except UnicodeDecodeError:
+            with open(self.filename, encoding='iso-8859-1') as f:
+                self._contents = f.read()
 
     def __getitem__(self, item):
         return self._cp[item]

gbp/git/vfs.py

@@ -33,7 +33,10 @@ def __init__(self, content, binary=False):
             if binary:
                 self._data = io.BytesIO(content)
             else:
-                self._data = io.StringIO(content.decode())
+                try:
+                    self._data = io.StringIO(content.decode())
+                except UnicodeDecodeError:
+                    self._data = io.StringIO(content.decode("iso-8859-1"))
 
         def readline(self):
             return self._data.readline()