From 8f56f86df5635cca21d24e3c03fb605ed9a956e1 Mon Sep 17 00:00:00 2001
From: atlas <atlas@hyperhive.local>
Date: Wed, 2 Sep 2026 11:42:04 +0200
Subject: [PATCH] ci: refuse relative markdown links in rust doc comments

check-doc-refs.sh's relative arm resolved every link against the linking
file's directory. That is right for markdown and wrong for a .rs doc
comment: rustdoc emits the href verbatim onto a page under
target/doc/<crate>/<module...>/, so the link resolves against THAT
directory instead.

The consequence was a false pass, not a miss -- a link resolving from the
source dir got certified while rendering broken in the published docs.
Reproduced against main's script: a `](../../docs/README.md)` planted in
hive-forge/src/client.rs resolves from hive-forge/src/ and the old rule
exits 0.

Refused rather than resolved rustdoc-aware. The repo has zero relative
links in .rs doc comments (measured on 54daf9ac), so nothing needs the
second reader, and the backticked repo-root form the root arm already
gates renders correctly under both. Inferring module nesting would be
machinery in service of a form nothing uses.

Closes #3928
---
 scripts/check-doc-refs.sh | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/scripts/check-doc-refs.sh b/scripts/check-doc-refs.sh
index b4ead89e..24894438 100755
--- a/scripts/check-doc-refs.sh
+++ b/scripts/check-doc-refs.sh
@@ -60,6 +60,26 @@ while IFS=: read -r file lineno match; do
   [ -n "${match:-}" ] || continue
   exempt "$file" "$lineno" && continue
   link="${match#](}"
+  # A `.rs` doc comment has a second renderer, and it does not count `../`
+  # the way the rest of this arm assumes. rustdoc emits the href verbatim
+  # onto a page at `target/doc/<crate>/<module…>/`, so the link resolves
+  # against *that* directory, not the source file's. Resolving from the
+  # source therefore certifies links that render broken — a false pass, not
+  # a miss, and worse than no check.
+  #
+  # Refused rather than resolved rustdoc-aware: the repo has zero relative
+  # links in `.rs` doc comments (measured on this commit), so nothing needs
+  # the second reader, and the backticked repo-root form the root arm above
+  # already gates works under both. Inferring module nesting would be
+  # machinery in service of a form nothing uses.
+  case "$file" in
+    *.rs)
+      dead=$((dead + 1))
+      printf '::error file=%s,line=%s::relative markdown link in a rust doc comment renders against the rustdoc output directory, not this file; use a backticked repo-root pointer instead: %s\n' \
+        "$file" "$lineno" "$link"
+      continue
+      ;;
+  esac
   # Resolved from the linking file's directory, so `../` counts the same way
   # the renderer counts it. `-m` keeps a link that escapes the repo root
   # resolvable enough to report rather than erroring out here.