Fixes the warnings:

backend/comics/comics-document.c:767:21: style: Condition 'bytes<=0' is always true [knownConditionTrueFalse]

backend/epub/minizip/unzip.c:603:25: style: Condition 'unz_copyright[0]!=' '' is always false [knownConditionTrueFalse]

properties/ev-properties-view.c:197:33: style: Condition 'text' is always true [knownConditionTrueFalse]

shell/ev-sidebar-thumbnails.c:598:7: style: Condition '!loading_icon' is always true [knownConditionTrueFalse]

shell/main.c:115:6: style: Condition '!error' is always true [knownConditionTrueFalse]

This reverts commit bb8194a94310dae72bcbd745cd7f0f93e8d6fad1.

Commit cases a warning when closing atril window, see
https://github.com/mate-desktop/atril/pull/431#issuecomment-576002680
for more info

 ev_sidebar_thumbnails_document_changed_cb()

Clear the loading icon hash table if it already exists.

https://bugzilla.gnome.org/show_bug.cgi?id=770070

origin commit:
https://gitlab.gnome.org/GNOME/evince/commit/702c7c6

After activating or deactivating fullscreen mode, the sidebar
window is automatically moved to its start, while scroll bar
stays in its original position.

The sidebar window move is unwanted and unsolicited, and it's
most probably caused by GtkIconView or GtkScrolledWindow bug.

Workaround this by having the sidebar sync its window with the
current scroll position after a fullscreen operation, do that by
just emitting a "value-changed" on the current scroll adjustment.

https://bugzilla.gnome.org/show_bug.cgi?id=783404
origin commit:
https://git.gnome.org/browse/evince/commit/?id=2bfb8fa

Preload both before and after current visible scrolling range,
the same amount of thumbnails in it, to help prevent thumbnail
creation happening in the user's sight.

https://bugzilla.gnome.org/show_bug.cgi?id=342110#c15
origin commit:
https://git.gnome.org/browse/evince/commit/?id=1fc8c68

Evince renders thumbnails on-the-fly as they get into the
scrolling visible area, but at the same time it will remove
them as they get out of the visible scrolling area, so when
user scrolls back to same position he will notice thumbnails
be recreated.

In pro of a more icing user experience, let's adopt a mixed approach
and keep the thumbnails that the user has already navigated, so
when he scrolls back and forth in the same area no thumbnail
re-generation will be visible. This also matches behaviour with
other pdf readers.

https://bugzilla.gnome.org/show_bug.cgi?id=342110
origin commit:
https://git.gnome.org/browse/evince/commit/?id=121e4d9

Caused by GtkIconView doing an invalidate and relayout of *all*
items in the view anytime we update model data in any indiviual
item (which happens with all the items that are getting in and out
of the scrolling area while we scroll). This caused GtkIconView to
machine-gunned us with "size-allocate" signals, a signal we were
using to update thumbnails when the sidebar is resized.

Fixed by connecting to the GtkTreeModel "row-changed" signal before
GtkIconView does it, and stop emission from there.

As we don't depend now on "size-allocate" signals to show thumbnails
while we scroll, just queue a draw on the icon view when a
thumbnail finish rendering.

Thanks Jose Aliste for first spotting the problem.

https://bugzilla.gnome.org/show_bug.cgi?id=691448
origin commit:
https://git.gnome.org/browse/evince/commit/?id=6480c70

Fixes https://github.com/mate-desktop/atril/issues/255