contact/invoice import: better exception handling.

see #3904

gui/qt/contact_list.py

@@ -26,7 +26,7 @@ import webbrowser
 
 from electrum.i18n import _
 from electrum.bitcoin import is_address
-from electrum.util import block_explorer_URL
+from electrum.util import block_explorer_URL, FileImportFailed
 from electrum.plugins import run_hook
 from PyQt5.QtGui import *
 from PyQt5.QtCore import *
@@ -57,7 +57,10 @@ class ContactList(MyTreeWidget):
         filename, __ = QFileDialog.getOpenFileName(self.parent, "Select your wallet file", wallet_folder)
         if not filename:
             return
-        self.parent.contacts.import_file(filename)
+        try:
+            self.parent.contacts.import_file(filename)
+        except FileImportFailed as e:
+            self.parent.show_message(str(e))
         self.on_update()
 
     def create_menu(self, position):

gui/qt/invoice_list.py

@@ -25,7 +25,7 @@
 
 from .util import *
 from electrum.i18n import _
-from electrum.util import format_time
+from electrum.util import format_time, FileImportFailed
 
 
 class InvoiceList(MyTreeWidget):
@@ -61,7 +61,10 @@ class InvoiceList(MyTreeWidget):
         filename, __ = QFileDialog.getOpenFileName(self.parent, "Select your wallet file", wallet_folder)
         if not filename:
             return
-        self.parent.invoices.import_file(filename)
+        try:
+            self.parent.invoices.import_file(filename)
+        except FileImportFailed as e:
+            self.parent.show_message(str(e))
         self.on_update()
 
     def create_menu(self, position):

lib/contacts.py

@@ -23,9 +23,12 @@
 import re
 import dns
 import json
+import traceback
+import sys
 
 from . import bitcoin
 from . import dnssec
+from .util import FileImportFailed, FileImportFailedEncrypted
 
 
 class Contacts(dict):
@@ -51,8 +54,12 @@ class Contacts(dict):
         try:
             with open(path, 'r') as f:
                 d = self._validate(json.loads(f.read()))
-        except:
-            return
+        except json.decoder.JSONDecodeError:
+            traceback.print_exc(file=sys.stderr)
+            raise FileImportFailedEncrypted()
+        except BaseException:
+            traceback.print_exc(file=sys.stdout)
+            raise FileImportFailed()
         self.update(d)
         self.save()
 

lib/paymentrequest.py

@@ -40,6 +40,7 @@ except ImportError:
 from . import bitcoin
 from . import util
 from .util import print_error, bh2u, bfh
+from .util import FileImportFailed, FileImportFailedEncrypted
 from . import transaction
 from . import x509
 from . import rsakey
@@ -471,9 +472,12 @@ class InvoiceStore(object):
             with open(path, 'r') as f:
                 d = json.loads(f.read())
                 self.load(d)
-        except:
+        except json.decoder.JSONDecodeError:
             traceback.print_exc(file=sys.stderr)
-            return
+            raise FileImportFailedEncrypted()
+        except BaseException:
+            traceback.print_exc(file=sys.stdout)
+            raise FileImportFailed()
         self.save()
 
     def save(self):

lib/util.py

@@ -58,6 +58,19 @@ class InvalidPassword(Exception):
     def __str__(self):
         return _("Incorrect password")
 
+
+class FileImportFailed(Exception):
+    def __str__(self):
+        return _("Failed to import file.")
+
+
+class FileImportFailedEncrypted(FileImportFailed):
+    def __str__(self):
+        return (_('Failed to import file.') + ' ' +
+                _('Perhaps it is encrypted...') + '\n' +
+                _('Importing encrypted files is not supported.'))
+
+
 # Throw this exception to unwind the stack like when an error occurs.
 # However unlike other exceptions the user won't be informed.
 class UserCancelled(Exception):