Segmentation fault when drawing on canvas created with chafa_canvas_new_similar

[GuardKenzie]

What am I doing?

When trying to draw using chafa_canvas_draw_all_pixels to a canvas created with chafa_canvas_new_similar I get a segmentation fault.

I might be doing something wrong since I don't have a lot of experience with C but I have provided a minimum working example that demonstrates the issue.

Some things to note:

• I get no segmentation fault if I change the pixel mode to kitty.
• The issue persists whether using symbol tags CHAFA_SYMBOL_TAG_HALF or CHAFA_SYMBOL_TAG_ALL.
• There is no segmentation fault when drawing to the original canvas.
• The issue persists if I create a proper canvas config and initiate the canvas with that.

To reproduce

1. Create a ChafaCanvas canvas using chafa_canvas_new
2. Create another ChafaCanvas using chafa_canvas_new_similar(canvas)
3. Draw to the second canvas using chafa_canvas_draw_all_pixels

Minimum working example

#include <chafa.h>

#define PIX_WIDTH  3
#define PIX_HEIGHT 3
#define N_CHANNELS 4

int
main (int argc, char *argv [])
{
    const guint8 pixels [PIX_WIDTH * PIX_HEIGHT * N_CHANNELS] =
    {
        0xff, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff,
        0x00, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0xff,
        0xff, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff
    };

    ChafaCanvas *canvas, *canvas2;

    canvas  = chafa_canvas_new(NULL);
    canvas2 = chafa_canvas_new_similar(canvas);

    chafa_canvas_draw_all_pixels (canvas2,
                                  CHAFA_PIXEL_RGBA8_UNASSOCIATED,
                                  pixels,
                                  PIX_WIDTH,
                                  PIX_HEIGHT,
                                  PIX_WIDTH * N_CHANNELS);

    return 0;
}

Backtrace

(gdb) bt full
#0  0x00007ffff7f6a560 in ?? () from /usr/lib/libchafa.so.0
No symbol table info available.
#1  0x00007ffff7f51b2e in ?? () from /usr/lib/libchafa.so.0
No symbol table info available.
#2  0x00007ffff7f52015 in ?? () from /usr/lib/libchafa.so.0
No symbol table info available.
#3  0x00007ffff7f53130 in ?? () from /usr/lib/libchafa.so.0
No symbol table info available.
#4  0x00007ffff7e87673 in g_thread_pool_thread_proxy (data=<optimized out>)
    at ../glib/glib/gthreadpool.c:352
        task = 0x5555555a6f70
        pool = 0x55555559cfa0
#5  0x00007ffff7e81e05 in g_thread_proxy (data=0x55555555ab00)
    at ../glib/glib/gthread.c:831
        thread = 0x55555555ab00
        __func__ = "g_thread_proxy"
#6  0x00007ffff7c9e8fd in start_thread (arg=<optimized out>)
    at pthread_create.c:442
        ret = <optimized out>
        pd = <optimized out>
        out = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140737297594048, 
                -8044589460357361681, -128, 11, 140737488345696, 
                140737289203712, 8044565556210978799, 8044571403542220783}, 
              mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, 
            data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#7  0x00007ffff7d20a60 in clone3 ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
No locals.

System info

os: arch linux
kernel: 5.15.85-1-lts
chafa version: 1.12.4

[hpjansson]

Thanks for reporting this! The fix will be in the next tarball release, hopefully later this month.

[GuardKenzie]

Awesome! Thank you!

[hpjansson]

1.14 is taking longer than expected, so I made 1.12.5 as a bugfix release in the meantime. Sorry for the delay!

[GuardKenzie]

Hey no worries! Thanks for the release! 🧡