From 530412529079dc8cd9c37c7d66120785474e6cc6 Mon Sep 17 00:00:00 2001
From: Rowan Cockett <rowanc1@gmail.com>
Date: Mon, 6 Jan 2025 08:45:10 -0700
Subject: [PATCH] =?UTF-8?q?=F0=9F=8F=B7=EF=B8=8F=20Label=20duplication=20w?=
 =?UTF-8?q?arning?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .changeset/lucky-squids-hug.md    | 5 +++++
 packages/myst-common/src/utils.ts | 7 ++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/lucky-squids-hug.md

diff --git a/.changeset/lucky-squids-hug.md b/.changeset/lucky-squids-hug.md
new file mode 100644
index 000000000..0f5c57940
--- /dev/null
+++ b/.changeset/lucky-squids-hug.md
@@ -0,0 +1,5 @@
+---
+"myst-common": patch
+---
+
+Improve label duplication warning
diff --git a/packages/myst-common/src/utils.ts b/packages/myst-common/src/utils.ts
index 10b9d400f..bf7098228 100644
--- a/packages/myst-common/src/utils.ts
+++ b/packages/myst-common/src/utils.ts
@@ -90,11 +90,16 @@ export function createHtmlId(identifier?: string): string | undefined {
  */
 export function transferTargetAttrs(sourceNode: GenericNode, destNode: GenericNode, vfile?: VFile) {
   if (sourceNode.label) {
-    if (destNode.label && vfile) {
+    if (destNode.label && vfile && destNode.label !== sourceNode.label) {
       fileWarn(vfile, `label "${destNode.label}" replaced with "${sourceNode.label}"`, {
         node: destNode,
       });
     }
+    if (destNode.label && vfile && destNode.label === sourceNode.label) {
+      fileWarn(vfile, `duplicate label "${destNode.label}" replacement`, {
+        node: destNode,
+      });
+    }
     destNode.label = sourceNode.label;
     delete sourceNode.label;
   }