documentation: Remove duplicate heading IDs on server side.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

tools/documentation_crawler/documentation_crawler/spiders/common/spiders.py

@@ -40,8 +40,6 @@ EXCLUDED_URLS = [
 
 VNU_IGNORE = [
     # Real errors that should be fixed.
-    r"Duplicate ID “[^”]*”\.",
-    r"The first occurrence of ID “[^”]*” was here\.",
     r"Attribute “markdown” not allowed on element “div” at this point\.",
     r"No “p” element in scope but a “p” end tag seen\.",
     (

web/src/portico/help.js

@@ -97,9 +97,6 @@ function render_code_sections() {
 new SimpleBar($(".markdown")[0]);
 new SimpleBar($(".sidebar")[0]);
 
-// Remove ID attributes from sidebar links so they don't conflict with index page anchor links
-$(".help .sidebar h1, .help .sidebar h2, .help .sidebar h3").removeAttr("id");
-
 // Scroll to anchor link when clicked. Note that landing-page.js has a
 // similar function; this file and landing-page.js are never included
 // on the same page.

zerver/views/documentation.py

@@ -68,6 +68,7 @@ class ApiURLView(TemplateView):
         return context
 
 
+sidebar_headings = XPath("//*[self::h1 or self::h2 or self::h3 or self::h4]")
 sidebar_links = XPath("//a[@href=$url]")
 
 
@@ -239,6 +240,12 @@ class MarkdownDirectoryView(ApiURLView):
             home_link.text = context["doc_root_title"] + " home"
             tree.insert(0, home_h1)
         url = context["doc_root"] + article
+        # Remove ID attributes from sidebar headings so they don't conflict with index page headings
+        headings = sidebar_headings(tree)
+        assert isinstance(headings, list)
+        for h in headings:
+            assert isinstance(h, _Element)
+            h.attrib.pop("id", "")
         # Highlight current article link
         links = sidebar_links(tree, url=url)
         assert isinstance(links, list)