GDK region assertion

amar.akshat · **Joined:** Mon Sep 17, 2012 9:36 am **Posts:** 3

Hi, I have a piece of code, which is sets up the label of a button multiple times very quickly in a loop. However in multiple runs, I am coming across an assertion which I am unable to figure out why?

I think there is something in gtk_label_set_markup() which I am missing.The assertion is:

Quote:

Gdk:ERROR:/build/buildd/gtk+2.0-2.24.6/gdk/gdkregion-generic.c:1110:miUnionNonO: assertion failed: (y1 < y2)

And the core dump says:

Quote:

(gdb) bt
#0 0x0045a416 in __kernel_vsyscall ()
#1 0x009e5c8f in __GI_raise (sig=6)
at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#2 0x009e92b5 in __GI_abort () at abort.c:92
#3 0x00bdc6ce in g_assertion_message ()
from /lib/i386-linux-gnu/libglib-2.0.so.0
#4 0x00bdcccf in g_assertion_message_expr ()
from /lib/i386-linux-gnu/libglib-2.0.so.0
#5 0x00381310 in ?? () from /usr/lib/i386-linux-gnu/libgdk-x11-2.0.so.0
#6 0x00382392 in ?? () from /usr/lib/i386-linux-gnu/libgdk-x11-2.0.so.0
#7 0x00382d24 in gdk_region_union ()
from /usr/lib/i386-linux-gnu/libgdk-x11-2.0.so.0
#8 0x0038cddb in ?? () from /usr/lib/i386-linux-gnu/libgdk-x11-2.0.so.0
#9 0x006cde27 in ?? () from /usr/lib/i386-linux-gnu/libgtk-x11-2.0.so.0
#10 0x006d4026 in ?? () from /usr/lib/i386-linux-gnu/libgtk-x11-2.0.so.0
#11 0x006d40b3 in gtk_widget_queue_resize ()
from /usr/lib/i386-linux-gnu/libgtk-x11-2.0.so.0
#12 0x00582fe2 in ?? () from /usr/lib/i386-linux-gnu/libgtk-x11-2.0.so.0
#13 0x00584658 in gtk_label_set_markup ()
from /usr/lib/i386-linux-gnu/libgtk-x11-2.0.so.0
#14 0x080850ea in set_button_label_text (text=0xb763751c "LT100223", rubno=6)

akalanka · **Joined:** Sun Sep 16, 2012 8:40 am **Posts:** 3

Can you post the code you have used before so I can take a look at it and then provide you a solution?

amar.akshat · **Joined:** Mon Sep 17, 2012 9:36 am **Posts:** 3

Code:

void set_text(gchar * text,  GtkWidget* widg)
{
        gchar bLRustr[256];
        g_strlcpy(bLRustr, "<span font_desc='", sizeof bLRustr);
        g_strlcat(bLRustr, tu->u_button_number_font, sizeof bLRustr);
        g_strlcat(bLRustr, "'><b>", sizeof bLRustr);
        g_strlcat(bLRustr, text, sizeof bLRustr);
        g_strlcat(bLRustr, "</b></span>", sizeof bLRustr);
        // set the Top Label on the Button
        gtk_label_set_markup(GTK_LABEL(widg),bLRustr);
}

Basically there are several functions like the one written above. During load testing, when I am setting the text of a label many times in a loop, the software crashes with an assertion,

Quote:

Gdk:ERROR:/build/buildd/gtk+2.0-2.24.6/gdk/gdkregion-generic.c:1110:miUnionNonO: assertion failed: (y1 < y2)

errol · **Posted:** Wed Sep 19, 2012 7:57 am

Hi,

It is a bit hard to tell what has really happened with such a short section of code and not knowing what the inputs are. My only thoughts are

- You may be providing invalid input causing bad mark-up.
- You could be overflowing the buffer again causing bad mark-up. Note you have space only for another 222 characters of data.

To avoid the second case I would use something like the example below. This still does not guard against invalid mark-up.
Note you will need to include the header file <glib/gprintf.h>.

Code:

void set_text(gchar * text,  GtkWidget* widg)
{
        gchar *bLRustr;

        bLRustr = g_strdup_printf("<span font_desc='%s'><b>%s</b></span>",
            tu->u_button_number_font, text);

        // set the Top Label on the Button
        gtk_label_set_markup(GTK_LABEL(widg), bLRustr);

        g_free(bLRustr);
}

amar.akshat · **Joined:** Mon Sep 17, 2012 9:36 am **Posts:** 3

I do understand your point, and that was my first thought as well,
however in the stack trace, if you notice the text I am passing is

Quote:

LT100223

Code:

#13 0x00584658 in gtk_label_set_markup ()
from /usr/lib/i386-linux-gnu/libgtk-x11-2.0.so.0
#14 0x080850ea in set_button_label_text (text=0xb763751c "LT100223", rubno=6)

I dont see a reason why it should get corrupted with a string of length 8.
Having said that, your idea is noble, and I shall try and load test with that.

errol · **Posted:** Thu Sep 20, 2012 5:42 pm

I ignored your stack trace as it did not seam to correspond to your sample code.

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GDK region assertion

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