bug#20452: 25.0.50; [PATCH] Invalid compilation warning about GTK+ when using GTK+ 3

bug#20452: 25.0.50; [PATCH] Invalid compilation warning about GTK+ when using GTK+ 3

[Aku Kotkavuo]

When compiling the latest version of Emacs, I encountered a warning
about my GTK+ version during the configuration phase:

> configure: WARNING: Your version of Gtk+ will have problems with
>        closing open displays.  This is no problem if you just use
>        one display, but if you use more than one and close one of them
>        Emacs may crash.

This seemed curious to me, so I dug in a little deeper and noticed that
this part of the configure script was written in 2008 and was supposed
to warn users of GTK+ 2.8 and earlier, released in 2005. I'm using GTK+
3.14.

I wrote a tiny patch to fix the check.

(Maybe the whole warning should be removed? Is there someone still using
GTK+ 2.8 or older?)


From 25ada920247cda3ed9d074c7e3eab6313548370d Mon Sep 17 00:00:00 2001
From: Aku Kotkavuo <aku.kotkavuo@gmail.com>
Date: Wed, 29 Apr 2015 00:32:19 +0300
Subject: [PATCH] Don't warn about too old GTK+ when using GTK+ 3

---
 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index d2f21ee..2d2fefa 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2496,7 +2496,7 @@ if test x"$pkg_check_gtk" = xyes; then
     GTK_OBJ="gtkutil.o $GTK_OBJ"
     term_header=$gtk_term_header
     USE_X_TOOLKIT=none
-    if "$PKG_CONFIG" --atleast-version=2.10 gtk+-2.0; then
+    if "$PKG_CONFIG" --atleast-version=2.10 gtk+-2.0 || "$PKG_CONFIG" gtk+-3.0; then
       :
     else
       AC_MSG_WARN([[Your version of Gtk+ will have problems with
-- 
2.1.4

bug#20452: 25.0.50; [PATCH] Invalid compilation warning about GTK+ when using GTK+ 3

[Stefan Monnier]

> (Maybe the whole warning should be removed? Is there someone still using
> GTK+ 2.8 or older?)

IIUC This Gtk+ bug is still open.  Or am I confusing this with another issue?


        Stefan

bug#20452: 25.0.50; [PATCH] Invalid compilation warning about GTK+ when using GTK+ 3

[Jan D.]

Hi.

> 29 apr 2015 kl. 05:25 skrev Stefan Monnier <monnier@iro.umontreal.ca>:
> 
>> (Maybe the whole warning should be removed? Is there someone still using
>> GTK+ 2.8 or older?)
> 
> IIUC This Gtk+ bug is still open.  Or am I confusing this with another issue?


The bug is still open.  It looked like it was fixed for 2.10 (it did not crash), but that might have been a fluke.
Its easy to crash Gtk+ with multiple displays.  They just don’t care about the issue.

	Jan D.

bug#20452: 25.0.50; [PATCH] Invalid compilation warning about GTK+ when using GTK+ 3

[Glenn Morris]

"Jan D." wrote:

> The bug is still open. It looked like it was fixed for 2.10 (it did
> not crash), but that might have been a fluke. Its easy to crash Gtk+
> with multiple displays. They just don't care about the issue.

It sounds like Emacs's configure.ac is still wrong.
It's warning for gtk2 < 2.10, or any gtk3.
That seems like a nonsensical combination.

Cf emacs.c's 'due to a long standing Gtk bug...' warning,
which it seems to issue whenever USE_GTK is defined, regardless of
version.

bug#20452: 25.0.50; [PATCH] Invalid compilation warning about GTK+ when using GTK+ 3

[Aku Kotkavuo]

>> The bug is still open. It looked like it was fixed for 2.10 (it did
>> not crash), but that might have been a fluke. Its easy to crash Gtk+
>> with multiple displays. They just don't care about the issue.

Oh. I haven’t encountered this bug and assumed that it was fixed in 2.10.

Is there an open bug filed in GTK+ bugzilla for this? \x10I tried to search for something that matches the description but I came up empty.

> It sounds like Emacs's configure.ac is still wrong.
> It's warning for gtk2 < 2.10, or any gtk3.
> That seems like a nonsensical combination.
> 
> Cf emacs.c's 'due to a long standing Gtk bug...' warning,
> which it seems to issue whenever USE_GTK is defined, regardless of
> version.

If this affects everyone, maybe this warning should be replaced with an entry to etc/PROBLEMS?

bug#20452: 25.0.50; [PATCH] Invalid compilation warning about GTK+ when using GTK+ 3

[Stefan Monnier]

> Is there an open bug filed in GTK+ bugzilla for this?

Of course: http://bugzilla.gnome.org/show_bug.cgi?id=85715

> I tried to search for something that matches the description but
> I came up empty.

Indeed, we emit the above URL from emacs.c when we're about to crash,
but we could/should also include this URL in the configure.ac message,
I think.


        Stefan

bug#20452: 25.0.50; [PATCH] Invalid compilation warning about GTK+ when using GTK+ 3

[Glenn Morris]

Aku Kotkavuo wrote:

> If this affects everyone, maybe this warning should be replaced with
> an entry to etc/PROBLEMS?

There is one already.

    ** When Emacs is compiled with Gtk+, closing a display kills Emacs.

You may get the subtle hint (PROBLEMS, warnings at configure, runtime)
here that Emacs takes this more seriously than the Gtk people seem to...
:)

bug#20452: 25.0.50; [PATCH] Invalid compilation warning about GTK+ when using GTK+ 3

[Jan D.]

Fixed in trunk.

	Jan D.

> 29 apr 2015 kl. 15:30 skrev Stefan Monnier <monnier@iro.umontreal.ca>:
> 
>> Is there an open bug filed in GTK+ bugzilla for this?
> 
> Of course: http://bugzilla.gnome.org/show_bug.cgi?id=85715
> 
>> I tried to search for something that matches the description but
>> I came up empty.
> 
> Indeed, we emit the above URL from emacs.c when we're about to crash,
> but we could/should also include this URL in the configure.ac message,
> I think.
> 
> 
>        Stefan