Bug 1862039 - Pref webgl_gl_khr_no_error off on Linux. r=gfx-reviewer…

…s,jgilbert,jrmuizel

Ideally we'd check whether we are using mesa, but we have to make the decision before creating the context and need the latter to know whether mesa is involved.

Differential Revision: https://phabricator.services.mozilla.com/D193053

dom/canvas/test/webgl-conf/generated-mochitest.ini

@@ -7661,7 +7661,7 @@ subsuite = webgl2-core
 skip-if = 1
 [generated/test_2_conformance2__transform_feedback__transform_feedback.html]
 subsuite = webgl2-core
-skip-if = (os == 'linux' && debug) || (os == 'android' && debug)
+skip-if = (os == 'linux') || (os == 'android' && debug)
 [generated/test_2_conformance2__transform_feedback__two-unreferenced-varyings.html]
 subsuite = webgl2-core
 [generated/test_2_conformance2__transform_feedback__unwritten-output-defaults-to-zero.html]

dom/canvas/test/webgl-conf/mochitest-errata.ini

@@ -61,7 +61,7 @@ fail-if = (os == 'linux')
 [generated/test_2_conformance2__transform_feedback__transform_feedback.html]
 # Linux: Assertion failure: [GFX1]: void mozilla::gl::GLContext::fTransformFeedbackVaryings(GLuint, GLsizei, const GLchar *const *, GLenum): Generated unexpected GL_INVALID_OPERATION error
 # Android: void mozilla::gl::GLContext::fDeleteTransformFeedbacks(GLsizei, const GLuint *): Generated unexpected GL_INVALID_OPERATION error.
-skip-if = (os == 'linux' && debug) || (os == 'android' && debug)
+skip-if = (os == 'linux') || (os == 'android' && debug)
 [generated/test_2_conformance__context__context-attributes-alpha-depth-stencil-antialias.html]
 # contextAttribs.antialias should be true. Was false
 fail-if = (os == 'linux')

modules/libpref/init/StaticPrefList.yaml

@@ -15184,6 +15184,12 @@
   type: RelaxedAtomicBool
 #ifdef XP_WIN
   value: false
+#elif defined(MOZ_WIDGET_GTK)
+  # Bug 1862039 - All versions of Mesa as of Nov 2023 have issues with
+  # GL_CONTEXT_FLAG_NO_ERROR_BIT. We should aspire to reenable it at
+  # some point when the bugs are fixed.
+  # See also https://gitlab.freedesktop.org/mesa/mesa/-/issues/10062
+  value: false
 #else
   value: true
 #endif