diff --git a/components/script/dom/webglrenderingcontext.rs b/components/script/dom/webglrenderingcontext.rs
index 8e4757a58417..628f69e736bd 100644
--- a/components/script/dom/webglrenderingcontext.rs
+++ b/components/script/dom/webglrenderingcontext.rs
@@ -1866,6 +1866,9 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
if !self.validate_framebuffer_complete() {
return;
}
+ if mask & !(constants::DEPTH_BUFFER_BIT | constants::STENCIL_BUFFER_BIT | constants::COLOR_BUFFER_BIT) != 0 {
+ return self.webgl_error(InvalidValue);
+ }
self.send_command(WebGLCommand::Clear(mask));
self.mark_as_dirty();
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 47eea45772bc..c84b409d5a6c 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -39229,6 +39229,12 @@
{}
]
],
+ "mozilla/webgl/clear.html": [
+ [
+ "/_mozilla/mozilla/webgl/clear.html",
+ {}
+ ]
+ ],
"mozilla/webgl/context_creation_error.html": [
[
"/_mozilla/mozilla/webgl/context_creation_error.html",
@@ -70864,6 +70870,10 @@
"c333c7b99156d63fcd3ad28014c7915a12cf8169",
"testharness"
],
+ "mozilla/webgl/clear.html": [
+ "14cc534be5da96b0cc128d5c44f662b2fdfb294c",
+ "testharness"
+ ],
"mozilla/webgl/clearcolor.html": [
"942ee78ec987d17f63253ed97d6de958dbe8730d",
"reftest"
diff --git a/tests/wpt/mozilla/tests/mozilla/webgl/clear.html b/tests/wpt/mozilla/tests/mozilla/webgl/clear.html
new file mode 100644
index 000000000000..b03c9a450f2f
--- /dev/null
+++ b/tests/wpt/mozilla/tests/mozilla/webgl/clear.html
@@ -0,0 +1,23 @@
+
+
+WebGLRenderingContext.clear testing (issue #20623)
+
+
+