textview: fix precondition assertions
authorChristian Hergert <chergert@redhat.com>
Tue, 24 Nov 2020 16:29:52 +0000 (08:29 -0800)
committerChristian Hergert <chergert@redhat.com>
Tue, 24 Nov 2020 16:29:52 +0000 (08:29 -0800)
commit1e994419ee172906b0d9edd7a3fe7490f9c2aba6
tree0ad9c0ef8b25be720ff624a368cce4826790e9ce
parent7b22c44b39d63cf6a1efb656921e56ac861803fc
textview: fix precondition assertions

It is a programmer error to call this with a child widget that has not
been placed within the GtkTextView.

Fixes #3386
gtk/gtktextview.c