Add common message text sanitization.

1 files changed, 35 insertions, 1 deletions

diff --git a/alot/settings/manager.py b/alot/settings/manager.py
index 1be5a0cc..a1e2ab6d 100644
--- a/alot/settings/manager.py
+++ b/alot/settings/manager.py
@@ -2,8 +2,9 @@
 # This file is released under the GNU GPL, version 3 or a later revision.
 # For further details see the COPYING file
 
-from   datetime           import datetime, timedelta
+from   datetime             import datetime, timedelta
 import email
+from   functools            import cached_property
 import importlib.util
 import itertools
 import logging
@@ -596,3 +597,36 @@ class SettingsManager:
             else:
                 rep = _pretty_datetime(d)
         return rep
+
+    def _make_trans_table(self, tab_width):
+        table = {}
+
+        # remove C1 control codes
+        for i in range(0x80, 0xa0):
+            table[i] = None
+
+        # replace C0 control codes with characters for their graphical
+        # representations i.e. "control pictures", which start at U+2400
+        for i in range(ord(' ')):
+            table[i] = 0x2400 + i
+
+        # "delete" character
+        table[0x7f] = 0x2421
+
+        # delete LF
+        table[ord('\r')] = None
+
+        # handle CR normally
+        del table[ord('\n')]
+
+        # expand tabs
+        table[ord('\t')] = ' ' * tab_width
+
+        return table
+
+    @cached_property
+    def sanitize_text_table(self):
+        return self._make_trans_table(self.get('tabwidth'))
+    @cached_property
+    def sanitize_header_table(self):
+        return self._make_trans_table(1)