Ensure stable IDs for dfn refs in domintro sections

This change ensures that dfn references/links inside sections which follow
the class=domintro convention are output with IDs ending with “-dev” —
and most likely, without any additional ①, ②, etc., suffix.

Otherwise, without this change, dfn references/links inside class=domintro
sections are output with IDs of the form “ref-foo-①”, etc. — just as the
IDs output for such references/links outside of class=domintro sections.

So this change helps make it likely that dfn references/links inside
class=domintro sections end up with stable IDs useful for referencing from
MDN and other places — rather than “ref-foo-②”, etc.  IDs that might change
if some new reference to a term is added to a spec somewhere preceding a
class=domintro section where the term is referenced.

Relates to mdn/browser-compat-data#11088

bikeshed/dfnpanels.py

@@ -45,7 +45,10 @@ def addDfnPanels(doc, dfns):
             for i, el in enumerate(els):
                 refID = el.get("id")
                 if refID is None:
-                    refID = f"ref-for-{id}"
+                    if hasAncestor(el, lambda x: hasClass(x, "domintro")):
+                        refID = f"{id}-dev"
+                    else:
+                        refID = f"ref-for-{id}"
                     el.set("id", safeID(doc, refID))
                 if i == 0:
                     appendChild(

bikeshed/h/dom.py

@@ -803,7 +803,7 @@ def dedupIDs(doc):
                     continue
             if el.get("data-silently-dedup") is not None:
                 warnAboutDupes = False
-            if dupeId.startswith("ref-for-"):
+            if dupeId.startswith("ref-for-") or dupeId.endswith("-dev"):
                 warnAboutDupes = False
             # Try to de-dup the id by appending an integer after it.
             if warnAboutDupes:

bikeshed/unsortedJunk.py

@@ -1072,7 +1072,10 @@ def decorateAutolink(doc, el, linkType, linkText, ref):
     if el.get("id") is None:
         _, _, id = ref.url.partition("#")
         if id:
-            el.set("id", f"ref-for-{id}")
+            if hasAncestor(el, lambda x: hasClass(x, "domintro")):
+                el.set("id", f"{id}-dev")
+            else:
+                el.set("id", f"ref-for-{id}")
             el.set("data-silently-dedup", "")
 
     # Get all the values that the type expands to, add it as a title.