From: Magnus Jacobsson <Magnus.Jacobsson@berotec.se>
Date: Wed, 13 Jul 2022 06:17:54 +0000 (+0200)
Subject: gvLayoutJobs: initialize also root graph if it isn't already
X-Git-Tag: 5.0.1~31^2~7
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=23c2388d7bc353265bebe96dd9792422a749027e;p=graphviz

gvLayoutJobs: initialize also root graph if it isn't already

The root graph info is needed by gvLayoutJobs when doing subgraph
layout. This fixes a heap-buffer-overflow detected by ASan in the
test_subgraph_layout test.
---

diff --git a/lib/gvc/gvlayout.c b/lib/gvc/gvlayout.c
index 00ae33a4d..a8cde85c0 100644
--- a/lib/gvc/gvlayout.c
+++ b/lib/gvc/gvlayout.c
@@ -58,8 +58,10 @@ int gvLayoutJobs(GVC_t * gvc, Agraph_t * g)
 
     agbindrec(g, "Agraphinfo_t", sizeof(Agraphinfo_t), true);
     GD_gvc(g) = gvc;
-    if (g != agroot(g))
-	GD_gvc(agroot(g)) = gvc;
+    if (g != agroot(g)) {
+        agbindrec(agroot(g), "Agraphinfo_t", sizeof(Agraphinfo_t), true);
+        GD_gvc(agroot(g)) = gvc;
+    }
 
     if ((p = agget(g, "layout"))) {
         gvc->layout.engine = NULL;