Auto merge of #23653 - Manishearth:nested, r=jdm

Improve support for nested dictionaries

Fixes https://github.com/servo/servo/issues/23640

Some IDLs need `= null`, that's something that needs to be updated upstream too.

After talking with @bzbarsky I realized that it was our IDLs which were incorrect, causing Options to appear where we don't want them to. In the media code we _do_ want Options. `= null` is the correct fix for that (and should be upstreamed).

r? @jdm

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1 files changed, 2 insertions, 1 deletions

diff --git a/components/script/dom/bindings/codegen/parser/WebIDL.py b/components/script/dom/bindings/codegen/parser/WebIDL.py
index 31692bd1a2e..df88cf120dd 100644
--- a/components/script/dom/bindings/codegen/parser/WebIDL.py
+++ b/components/script/dom/bindings/codegen/parser/WebIDL.py
@@ -4611,7 +4611,8 @@ class IDLArgument(IDLObjectWithIdentifier):
 
         if ((self.type.isDictionary() or
              self.type.isUnion() and self.type.unroll().hasDictionaryType()) and
-            self.optional and not self.defaultValue and not self.variadic):
+            self.optional and not self.defaultValue and not self.variadic and
+            not self.dictionaryMember):
             # Default optional non-variadic dictionary arguments to null,
             # for simplicity, so the codegen doesn't have to special-case this.
             self.defaultValue = IDLNullValue(self.location)