From c782d0cc8c3f9eb8234b275cc33b19eb9732f882 Mon Sep 17 00:00:00 2001
From: Yarl Baudig <yarl-baudig@mailoo.org>
Date: Sun, 2 Nov 2025 09:09:52 +0100
Subject: [PATCH] graph: graphml backend: emit label
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* guix/graph.scm (emit-graphml-prologue): Declare label attribute.
(emit-graphml-node): Define label attribute.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>
---
 guix/graph.scm | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/guix/graph.scm b/guix/graph.scm
index 9f1111a0ae2799e4950a7e33f9a9da3016e00ad8..e661c95467221929c5ab066244bdcb0c1317a783 100644
--- a/guix/graph.scm
+++ b/guix/graph.scm
@@ -341,6 +341,7 @@ nodeArray.push(nodes[\"~a\"]);~%"
     xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"
     xsi:schemaLocation=\"http://graphml.graphdrawing.org/xmlns
      http://graphml.graphdrawing.org/xmlns/1.0/graphml.xsd\">
+  <key id=\"d0\" for=\"node\" attr.name=\"label\" attr.type=\"string\"/>
   <graph id=\"G\" edgedefault=\"directed\">~%"))
 
 (define (emit-graphml-epilogue port)
@@ -348,8 +349,11 @@ nodeArray.push(nodes[\"~a\"]);~%"
 </graphml>"))
 
 (define (emit-graphml-node id label port)
-  (format port "    <node id=\"~a\"/>~%"
-          (string-replace-substring (object->string id) "\"" "\\\"")))
+  (format port "    <node id=\"~a\">
+      <data key=\"d0\">~a</data>
+    </node>~%"
+          (string-replace-substring (object->string id) "\"" "\\\"")
+          label))
 
 (define (emit-graphml-edge id1 id2 port)
   (format port "    <edge source=\"~a\" target=\"~a\"/>~%"