Bug 137689 – gl.detachShader breaks shader program

• Status: RESOLVED
• Resolution: FIXED
• Component: WebGL

Calling gl.detachShader after linking results in a program that doesn't draw anything (without error messages to the console). AFAIK this should not happen and using detachShader and deleteShader is encouraged to reduce memory usage.
Here's a good test from when firefox had similar problems https://bugzilla.mozilla.org/show_bug.cgi?id=867253

[Radar WebKit Bug Importer]

<rdar://problem/34025056>

[Dean Jackson]

I am unable to reproduce this. See the attached test case which both detaches and deletes the shaders after linking the program, but before they are used in a draw call (and before they are used to get attribute and uniform locations).

[Dean Jackson]

Created attachment 318952 [details]
Testcase

[Dean Jackson]

Also, the original demo on flohofwoe doesn't seem to work any more, in any browser. It also downloads rather than running directly.

[Dean Jackson]

Oops. My test case is bad. This is really broken.

[Dean Jackson]

Created attachment 320217 [details]
Testcase

Better testcase. The triangle should be red.

[Dean Jackson]

Created attachment 320329 [details]
Patch

[Sam Weinig]

Comment on attachment 320329 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=320329&action=review

> Source/WebCore/ChangeLog:20
> +        This fixes the bug, but the whole area is still a bit messy. For one,
> +        we're keeping around all the shader information even after it is
> +        no longer used.

Seems like we should have a bug tracking this issue.

> Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:996
> +    LinkedShaderMap::iterator result = m_linkedShaderMap.find(program);

Use auto here?

> Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:1053
> +    LinkedShaderMap::iterator result = m_linkedShaderMap.find(program);

auto?

[Dean Jackson]

(In reply to Sam Weinig from comment #8)
> 
> Seems like we should have a bug tracking this issue.
> 

https://bugs.webkit.org/show_bug.cgi?id=98204

[Dean Jackson]

Committed r221831: <http://trac.webkit.org/changeset/221831>