Description of problem:
Crash occured while typing a Python script.

Version-Release number of selected component:
gnome-builder-3.18.1-2.fc23

Additional info:
reporter:       libreport-2.6.3
backtrace_rating: 4
cmdline:        /usr/bin/gnome-builder --gapplication-service
crash_function: IDE_IS_INDENTER
executable:     /usr/bin/gnome-builder
global_pid:     18939
kernel:         4.2.8-300.fc23.x86_64
runlevel:       N 5
type:           CCpp
uid:            1000

Truncated backtrace:
Thread no. 1 (10 frames)
 #0 IDE_IS_INDENTER at ide-indenter.h:30
 #1 ide_indenter_format at ide-indenter.c:85
 #2 ide_source_view_do_indent at ide-source-view.c:1962
 #3 ide_source_view_key_press_event at ide-source-view.c:2218
 #4 _gtk_marshal_BOOLEAN__BOXED at gtkmarshalers.c:86
 #9 gtk_widget_event_internal at gtkwidget.c:7692
 #10 gtk_window_propagate_key_event at gtkwindow.c:7775
 #11 gtk_window_key_press_event at gtkwindow.c:7808
 #12 _gtk_marshal_BOOLEAN__BOXED at gtkmarshalers.c:86
 #17 gtk_widget_event_internal at gtkwidget.c:7692