bug#20432: GDK_SCALE=2 GDK_DPI_SCALE=0.5 destroys GTK+ 3 scroll bar

["Jan D." <jan.h.d@swipnet.se>]

Hi.

Looks like you had an X protocol error.  Its possible we haven’t covered all cases for GDK_SCALE yet.

	Jan D.

> 15 maj 2015 kl. 04:59 skrev Paul Eggert <eggert@cs.ucla.edu>:
> 
> Jan D. wrote:
>>> By the way, on my Fedora 21 x86-64 host, setting GDK_SCALE=2
>>> GDK_DPI_SCALE=0.5 has no effect on emacs -Q, even with the recent
>>> fixes.  Perhaps this is due to the races you mentioned?
>> 
>> No, that just affects the initial frame size.
>> You should see an effect on toolbar and scroll bar size (they should be twice as
>> big).
> 
> Yes, you're right, it works.  I had misconfigured my Emacs (configured with the Lucid toolkit).  Sorry about the confusion.
> 
> I suppose I should mention that when I tried a properly-configured Emacs with GDK_SCALE=2 it dumped core for me.  I was running on Fedora 21 x86-64 (which has gtk3-3.14.13-1.fc21.x86_64) and displaying over the Internet to Ubuntu 15.04.  I can't reproduce the problem so it could be a timing thing.  The core dump occurs within gtk_window_get_size, which is called by xg_frame_set_char_size.   I wasn't running under a debugger, so I got only this backtrace:
> 
>> $ GDK_SCALE=2 src/emacs -Q
>> X protocol error: BadAccess (attempt to access private resource denied) on protocol request 130
>> When compiled with GTK, Emacs cannot recover from X disconnects.
>> This is a GTK bug: https://bugzilla.gnome.org/show_bug.cgi?id=85715
>> For details, see etc/PROBLEMS.
>> Fatal error 6: Aborted
>> Backtrace:
>> src/emacs[0x503bc2]
>> src/emacs[0x4ebb09]
>> src/emacs[0x503c53]
>> src/emacs[0x4be78e]
>> src/emacs[0x4c2a28]
>> src/emacs[0x4c2a8d]
>> /lib64/libX11.so.6(_XError+0x11d)[0x7f0edfd1d4dd]
>> /lib64/libX11.so.6(+0x42427)[0x7f0edfd1a427]
>> /lib64/libX11.so.6(+0x424e5)[0x7f0edfd1a4e5]
>> /lib64/libX11.so.6(_XReply+0x230)[0x7f0edfd1b490]
>> /lib64/libX11.so.6(XGetGeometry+0x8e)[0x7f0edfcffd9e]
>> /lib64/libgdk-3.so.0(+0x5d37f)[0x7f0ee1b7537f]
>> /lib64/libgdk-3.so.0(gdk_window_get_geometry+0x104)[0x7f0ee1b4e014]
>> /lib64/libgdk-3.so.0(gdk_screen_get_monitor_at_window+0x8f)[0x7f0ee1b4974f]
>> /lib64/libgtk-3.so.0(+0x332d79)[0x7f0ee2104d79]
>> /lib64/libgtk-3.so.0(+0x3367fb)[0x7f0ee21087fb]
>> /lib64/libgtk-3.so.0(gtk_window_get_size+0xab)[0x7f0ee210e88b]
>> src/emacs[0x4ddff8]
>> src/emacs[0x4c94fa]
>> src/emacs[0x4273b0]
>> src/emacs[0x4d2829]
>> src/emacs[0x55bb33]
>> src/emacs[0x58ecb3]
>> src/emacs[0x55b57f]
>> src/emacs[0x55b94b]
>> src/emacs[0x58ecb3]
>> src/emacs[0x55b94b]
>> src/emacs[0x58ecb3]
>> src/emacs[0x55b94b]
>> src/emacs[0x58ecb3]
>> src/emacs[0x55b94b]
>> src/emacs[0x58ecb3]
>> src/emacs[0x55aa08]
>> src/emacs[0x55ad0b]
>> src/emacs[0x55e2d1]
>> src/emacs[0x55a107]
>> src/emacs[0x4ee8ac]
>> src/emacs[0x559fe3]
>> src/emacs[0x4ebf08]
>> src/emacs[0x4f04bb]
>> src/emacs[0x4f0808]
>> ...
>> Aborted (core dumped)
> 
> 
> Addrline converts this to:
> 
> emacs_backtrace at /home/eggert/src/gnu/emacs/static-checking/src/sysdep.c:2188
> terminate_due_to_signal at /home/eggert/src/gnu/emacs/static-checking/src/emacs.c:374
> emacs_abort at /home/eggert/src/gnu/emacs/static-checking/src/sysdep.c:2201
> x_connection_closed at /home/eggert/src/gnu/emacs/static-checking/src/xterm.c:8525
> x_error_quitter at /home/eggert/src/gnu/emacs/static-checking/src/xterm.c:8617
> x_error_handler at /home/eggert/src/gnu/emacs/static-checking/src/xterm.c:8588
> ?? ??:0
> ?? ??:0
> ?? ??:0
> ?? ??:0
> ?? ??:0
> ?? ??:0
> ?? ??:0
> ?? ??:0
> ?? ??:0
> ?? ??:0
> ?? ??:0
> xg_clear_under_internal_border at /home/eggert/src/gnu/emacs/static-checking/src/gtkutil.c:848
> (inlined by) xg_frame_set_char_size at /home/eggert/src/gnu/emacs/static-checking/src/gtkutil.c:947
> x_set_window_size at /home/eggert/src/gnu/emacs/static-checking/src/xterm.c:9729
> adjust_frame_size at /home/eggert/src/gnu/emacs/static-checking/src/frame.c:491 (discriminator 8)
> Fx_create_frame at /home/eggert/src/gnu/emacs/static-checking/src/xfns.c:3305
> Ffuncall at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:2719
> exec_byte_code at /home/eggert/src/gnu/emacs/static-checking/src/bytecode.c:919
> funcall_lambda at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:2957
> backtrace_debug_on_exit at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:159
> (inlined by) Ffuncall at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:2791
> exec_byte_code at /home/eggert/src/gnu/emacs/static-checking/src/bytecode.c:919
> backtrace_debug_on_exit at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:159
> (inlined by) Ffuncall at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:2791
> exec_byte_code at /home/eggert/src/gnu/emacs/static-checking/src/bytecode.c:919
> backtrace_debug_on_exit at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:159
> (inlined by) Ffuncall at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:2791
> exec_byte_code at /home/eggert/src/gnu/emacs/static-checking/src/bytecode.c:919
> backtrace_debug_on_exit at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:159
> (inlined by) Ffuncall at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:2791
> exec_byte_code at /home/eggert/src/gnu/emacs/static-checking/src/bytecode.c:919
> apply_lambda at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:2829
> eval_sub at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:2256
> Feval at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:1997 (discriminator 3)
> internal_condition_case at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:1350
> top_level_1 at /home/eggert/src/gnu/emacs/static-checking/src/keyboard.c:1162
> internal_catch at /home/eggert/src/gnu/emacs/static-checking/src/eval.c:1110
> command_loop at /home/eggert/src/gnu/emacs/static-checking/src/keyboard.c:1118
> recursive_edit_1 at /home/eggert/src/gnu/emacs/static-checking/src/keyboard.c:729
> Frecursive_edit at /home/eggert/src/gnu/emacs/static-checking/src/keyboard.c:800