Prompt for non-existing download directories.

Closes #2120

qutebrowser/browser/downloads.py

@@ -27,6 +27,7 @@ import collections
 import functools
 import pathlib
 import tempfile
+import errno
 
 import sip
 from PyQt5.QtCore import (pyqtSlot, pyqtSignal, Qt, QObject, QModelIndex,
@@ -137,7 +138,8 @@ def create_full_filename(basename, filename):
     encoding = sys.getfilesystemencoding()
     filename = utils.force_encoding(filename, encoding)
     basename = utils.force_encoding(basename, encoding)
-    if os.path.isabs(filename) and os.path.isdir(filename):
+    if os.path.isabs(filename) and (os.path.isdir(filename) or
+                                    os.path.join(filename, "") == filename):
         # We got an absolute directory from the user, so we save it under
         # the default filename in that directory.
         return os.path.join(filename, basename)
@@ -657,11 +659,42 @@ class AbstractDownloadItem(QObject):
             self._filename = create_full_filename(self.basename,
                                                   os.path.expanduser('~'))
 
+        dirname = os.path.dirname(self._filename)
+        if not os.path.exists(dirname):
+            txt = ("<b>{}</b> does not exist. Create it?".
+                   format(html.escape(
+                       os.path.join(dirname, ""))))
+            self._ask_create_parent_question("Create directory?", txt,
+                                             force_overwrite,
+                                             remember_directory)
+        else:
+            self._after_create_parent_question(force_overwrite,
+                                               remember_directory)
+
+    def _after_create_parent_question(self,
+                                      force_overwrite, remember_directory):
+        """After asking about parent directory.
+
+        Args:
+            force_overwrite: Force overwriting existing files.
+            remember_directory: If True, remember the directory for future
+                                downloads.
+        """
+        global last_used_directory
+
+        try:
+            os.makedirs(os.path.dirname(self._filename))
+        except OSError as e:
+            # Unlikely, but could be created before
+            # we get a chance to create it.
+            if e.errno != errno.EEXIST:
+                raise
+
         self.basename = os.path.basename(self._filename)
         if remember_directory:
             last_used_directory = os.path.dirname(self._filename)
 
-        log.downloads.debug("Setting filename to {}".format(filename))
+        log.downloads.debug("Setting filename to {}".format(self._filename))
         if force_overwrite:
             self._after_set_filename()
         elif os.path.isfile(self._filename):

qutebrowser/browser/qtnetworkdownloads.py

@@ -203,6 +203,17 @@ class DownloadItem(downloads.AbstractDownloadItem):
                               no_action=no_action, cancel_action=no_action,
                               abort_on=[self.cancelled, self.error])
 
+    def _ask_create_parent_question(self, title, msg,
+                                    force_overwrite, remember_directory):
+        no_action = functools.partial(self.cancel, remove_data=False)
+        message.confirm_async(title=title, text=msg,
+                              yes_action=(lambda:
+                                          self._after_create_parent_question(
+                                              force_overwrite,
+                                              remember_directory)),
+                              no_action=no_action, cancel_action=no_action,
+                              abort_on=[self.cancelled, self.error])
+
     def _set_fileobj(self, fileobj, *, autoclose=True):
         """"Set the file object to write the download to.
 

qutebrowser/browser/webengine/webenginedownloads.py

@@ -120,6 +120,22 @@ class DownloadItem(downloads.AbstractDownloadItem):
                              "state {} (not in requested state)!".format(
                                  filename, self, state_name))
 
+    def _ask_create_parent_question(self, title, msg,
+                                    force_overwrite, remember_directory):
+        no_action = functools.partial(self.cancel, remove_data=False)
+        question = usertypes.Question()
+        question.title = title
+        question.text = msg
+        question.mode = usertypes.PromptMode.yesno
+        question.answered_yes.connect(lambda:
+                                      self._after_create_parent_question(
+                                          force_overwrite, remember_directory))
+        question.answered_no.connect(no_action)
+        question.cancelled.connect(no_action)
+        self.cancelled.connect(question.abort)
+        self.error.connect(question.abort)
+        message.global_bridge.ask(question, blocking=True)
+
     def _ask_confirm_question(self, title, msg):
         no_action = functools.partial(self.cancel, remove_data=False)
         question = usertypes.Question()

tests/end2end/features/downloads.feature

@@ -256,8 +256,11 @@ Feature: Downloading things from a website.
         Then the error "Can only download the current page as mhtml." should be shown
 
     Scenario: :download with a directory which doesn't exist
-        When I run :download --dest (tmpdir)/downloads/somedir/filename http://localhost:(port)/
+        When I run :download --dest (tmpdir)/downloads/somedir/filename http://localhost:(port)/data/downloads/download.bin
-        Then the error "Download error: No such file or directory" should be shown
+        And I wait for "Asking question <qutebrowser.utils.usertypes.Question default=None mode=<PromptMode.yesno: 1> text='<b>*</b> does not exist. Create it?' title='Create directory?'>, *" in the log
+        And I run :prompt-accept yes
+        And I wait until the download filename is finished
+        Then the downloaded file filename should not exist
 
     ## mhtml downloads