From: Matthew Fernandez <matthew.fernandez@gmail.com>
Subject: gvc: detect plugin installation failure and display an error
References: bsc#1219491
Patch-Mainline: 10.0.1
Git-commit: a95f977f5d809915ec4b14836d2b5b7f5e74881e
Git-repo: git@gitlab.com:graphviz/graphviz.git.git

Gitlab: fixes #2441
Reported-by: GJDuck

A malformed config6 file that leads to plugin search failing no longer causes
out-of-bounds memory reads. This now causes an error message and graceful
failure. #2441


Signed-off-by:  <trenn@suse.com>
Index: graphviz-2.49.3/lib/gvc/gvconfig.c
===================================================================
--- graphviz-2.49.3.orig/lib/gvc/gvconfig.c
+++ graphviz-2.49.3/lib/gvc/gvconfig.c
@@ -183,6 +183,10 @@ static int gvconfig_plugin_install_from_
 	do {
 	    api = token(&nest, &s);
 	    gv_api = gvplugin_api(api);
+	    if (gv_api == (api_t)-1) {
+		agerr(AGERR, "config error: %s %s not found\n", path, api);
+		return 0;
+	    }
 	    do {
 		if (nest == 2) {
 		    type = token(&nest, &s);