Threw a bug when I tried to make a link out of '-->' (User error?)

[tscahill]

To Reproduce
Steps to reproduce the behavior:

1. Type "-->". Zim converts this into a right-pointing arrow. (Very nice!)
2. Press Ctrl-L. Voila!
   As the error says: "raise ValueError('Not a valid page name: %s (was: %s)' % (newname, name))
   ValueError: Not a valid page name: (was: →)"

Environment (please complete the following information):

• Version [e.g. 0.74.0] -- This is running as source (launched with ./zim.py)
• OS: [e.g. linux/windows/mac os]
• Language: especially for errors that might relate to character encoding or other locale specific issues

Traceback

`This is zim 0.74.3
Platform: posix (Manjaro 21.1)
Locale: en_CA UTF-8
FS encoding: utf-8
Python: (3, 9, 7, 'final', 0)
PyGObject: (3, 42, 0)

======= Traceback =======
File "/home/tim/Downloads/Linux/Zim/zim-desktop-wiki-master/zim/actions.py", line 159, in _on_activate
self.call()
File "/home/tim/Downloads/Linux/Zim/zim-desktop-wiki-master/zim/actions.py", line 130, in call
return self._action.func(self._instance, *args, **kwargs)
File "/home/tim/Downloads/Linux/Zim/zim-desktop-wiki-master/zim/gui/pageview/init.py", line 7144, in insert_link
InsertLinkDialog(self, self).run()
File "/home/tim/Downloads/Linux/Zim/zim-desktop-wiki-master/zim/gui/pageview/init.py", line 8068, in init
self._text_for_link = self._link_to_text(href)
File "/home/tim/Downloads/Linux/Zim/zim-desktop-wiki-master/zim/gui/pageview/init.py", line 8122, in _link_to_text
parts = HRef.new_from_wiki_link(link).parts()
File "/home/tim/Downloads/Linux/Zim/zim-desktop-wiki-master/zim/notebook/page.py", line 360, in new_from_wiki_link
names = Path.makeValidPageName(href.lstrip('+')) if href else ""
File "/home/tim/Downloads/Linux/Zim/zim-desktop-wiki-master/zim/notebook/page.py", line 157, in makeValidPageName
raise ValueError('Not a valid page name: %s (was: %s)' % (newname, name))
ValueError: Not a valid page name: (was: →)`

[introt]

Can confirm, not a user error; can be reproduced with any string that "reduces to an empty string" by makeValidPageName, eg. ) or ??.

[introt]

While the fix makes _link_to_text return an empty string, the dialog gets filled with the original string, making it possible to create invalid links that open the bug dialog when activated:

======= Traceback =======
  File "/home/introt/repos/zim-desktop-wiki/zim/gui/pageview/__init__.py", line 6513, in do_activate_link
    self._do_activate_link(link, hints)
  File "/home/introt/repos/zim-desktop-wiki/zim/gui/pageview/__init__.py", line 6522, in _do_activate_link
    href = HRef.new_from_wiki_link(link)
  File "/home/introt/repos/zim-desktop-wiki/zim/notebook/page.py", line 359, in new_from_wiki_link
    names = Path.makeValidPageName(href.lstrip('+')) if href else ""
  File "/home/introt/repos/zim-desktop-wiki/zim/notebook/page.py", line 156, in makeValidPageName
    raise ValueError('Not a valid page name: %s (was: %s)' % (newname, name))
ValueError: Not a valid page name:  (was: →)

Since one can create these invalid links via other means, eg. editing page source, I'd consider that a separate issue whose fix would be showing an error dialog like the one shown with links to non-existing anchors.

[introt]

Haven't looked into zim.errors.exception_handler, but here's a quick mock of a patch

diff --git a/zim/gui/pageview/__init__.py b/zim/gui/pageview/__init__.py
index 83c63c42..57a67568 100644
--- a/zim/gui/pageview/__init__.py
+++ b/zim/gui/pageview/__init__.py
@@ -6511,6 +6511,8 @@ class PageView(GSignalEmitterMixin, Gtk.VBox):
        def do_activate_link(self, link, hints):
                try:
                        self._do_activate_link(link, hints)
+               except ValueError:
+                       ErrorDialog(self, _('Invalid link: "%s"') % link).run() # T: error when invalid link clicked
                except:
                        zim.errors.exception_handler(
                                'Exception during activate-link(%r)' % ((link, hints),))

[introt]

Could also switch out zim.errors.exception_handler with show_error...

[introt]

Fixed by 458688c (the fix for #1932), though it does result in the aforementioned ValueError: Not a valid page name: (was: →) on click.