Segmentation fault in opengl_utils.pyx

[SanAndreyas]

Software Versions

• Python: 3.11
• OS: Debian
• Kivy: 2.2.1
• Kivy installation method: pip

Describe the bug
Program received signal SIGSEGV, Segmentation fault.

import io
from kivy.core.image import Image as CoreImage
data = io.BytesIO(open("image.png", "rb").read())
texture = CoreImage(data, ext="png", filename="image.png").texture

Crashes !ONLY! when accessing ".texture".

Crash DUMP:
#0 0x0000000000000000 in ?? ()
#1 0x00007ffff5ce317a in __pyx_f_4kivy_8graphics_12opengl_utils_gl_get_extensions (__pyx_skip_dispatch=__pyx_skip_dispatch@entry=0) at /project/kivy/graphics/opengl_utils.c:3090
#2 0x00007ffff5ce47e4 in __pyx_f_4kivy_8graphics_12opengl_utils_gl_has_extension (__pyx_v_name=0x7ffff6857f00, __pyx_skip_dispatch=__pyx_skip_dispatch@entry=0) at /project/kivy/graphics/opengl_utils.c:3441
#3 0x00007ffff5ce8008 in __pyx_f_4kivy_8graphics_12opengl_utils_gl_has_capability (__pyx_v_cap=2, __pyx_skip_dispatch=) at /project/kivy/graphics/opengl_utils.c:3945
#4 0x00007ffff5e61db4 in __pyx_pf_4kivy_8graphics_7texture_2texture_create_from_data (__pyx_self=, __pyx_v_mipmap=, __pyx_v_im=) at /project/kivy/graphics/texture.c:10360
#5 __pyx_pw_4kivy_8graphics_7texture_3texture_create_from_data (__pyx_self=, __pyx_args=, __pyx_kwds=) at /project/kivy/graphics/texture.c:10245
#6 0x0000555555758c47 in cfunction_call (func=0x7ffff6821710, args=, kwargs=) at Objects/methodobject.c:542

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Expected behavior
No crash

To Reproduce
import io
from kivy.core.image import Image as CoreImage
data = io.BytesIO(open("image.png", "rb").read())
texture = CoreImage(data, ext="png", filename="image.png").texture

Code and Logs and screenshots

Crash DUMP:
#0  0x0000000000000000 in ?? ()
#1  0x00007ffff5ce317a in __pyx_f_4kivy_8graphics_12opengl_utils_gl_get_extensions (__pyx_skip_dispatch=__pyx_skip_dispatch@entry=0) at /project/kivy/graphics/opengl_utils.c:3090
#2  0x00007ffff5ce47e4 in __pyx_f_4kivy_8graphics_12opengl_utils_gl_has_extension (__pyx_v_name=0x7ffff6857f00, __pyx_skip_dispatch=__pyx_skip_dispatch@entry=0) at /project/kivy/graphics/opengl_utils.c:3441
#3  0x00007ffff5ce8008 in __pyx_f_4kivy_8graphics_12opengl_utils_gl_has_capability (__pyx_v_cap=2, __pyx_skip_dispatch=<optimized out>) at /project/kivy/graphics/opengl_utils.c:3945
#4  0x00007ffff5e61db4 in __pyx_pf_4kivy_8graphics_7texture_2texture_create_from_data (__pyx_self=<optimized out>, __pyx_v_mipmap=<optimized out>, __pyx_v_im=<optimized out>) at /project/kivy/graphics/texture.c:10360
#5  __pyx_pw_4kivy_8graphics_7texture_3texture_create_from_data (__pyx_self=<optimized out>, __pyx_args=<optimized out>, __pyx_kwds=<optimized out>) at /project/kivy/graphics/texture.c:10245
#6  0x0000555555758c47 in cfunction_call (func=0x7ffff6821710, args=<optimized out>, kwargs=<optimized out>) at Objects/methodobject.c:542

Additional context
Crashes !ONLY! when accessing ".texture".
Used latest version of SDL as well as older 2.26.5

[misl6]

This happens only when using CoreImage directly?

[SanAndreyas]

texture = CoreImage(data, ext="png", filename="image.png").texture # crashes
image = CoreImage(data, ext="png", filename="image.png") # does not crash

If I create the texture from a .png file directly and not from data, it works.
As you can see at #5 it crashes only when taking the texture from data in function texture_create_from_data() which eventually calls gl_get_extensions() where the actual seg fault happends.

[mak8kammerer]

Texture class use OpenGL functions. The OpenGL context is not created in your code, which leads to a segmentation fault.

[SanAndreyas]

Texture class use OpenGL functions. The OpenGL context is not created in your code, which leads to a segmentation fault.

Thank you for your analysis. Your suggestion indeed fixed the issue ( no segmentation fault ).

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.graphics import Color, Rectangle


class MyWidget(Widget):
    def __init__(self, **kwargs):
        super(MyWidget, self).__init__(**kwargs)
        with self.canvas:
            import io
            from kivy.core.image import Image as CoreImage
            data = io.BytesIO(open("image.png", "rb").read())
            texture = CoreImage(data, ext="png", filename="image.png").texture
            self.rect = Rectangle(pos=(100, 100), size=(200, 200), texture=texture)


class MyApp(App):
    def build(self):
        return MyWidget()


if __name__ == '__main__':
    MyApp().run()

[SanAndreyas]

I have now actually found on the texture page documentation the following:

Warning

Using Texture before OpenGL has been initialized will lead to a crash. If you need to create textures before the application has started, import Window first: from kivy.core.window import Window

from kivy.core.window import Window

import io
from kivy.core.image import Image as CoreImage
data = io.BytesIO(open("image.png", "rb").read())
texture = CoreImage(data, ext="png", filename="image.png").texture

This fixed the crash, seems to be a known limitation.